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Study Question: What are the downstream endocrine and paracrine consequences of letrozole (LZ) cotreatment during ovarian stimulation and is follicle growth and recruitment affected?Summary Answer: Letrozole cotreatment induces marked changes in both the follicular and luteal phase endocrinology causing potentiation of follicle diameter and an improved corpus luteum function without affecting the secondarily recruited follicle cohort.What Is Known Already: Letrozole is a third-generation aromatase inhibitor that is well-established as an effective ovulatory agent, while its possible benefits in standard in vitro fertilization protocols are less thoroughly investigated.Study Design, Size, Duration: This study included a double-blinded, placebo-controlled, randomized study with LZ or placebo intervention during ovarian stimulation for IVF treatment, an observational preceding baseline natural cycle and a succeeding follow-up visit. Participants were enrolled between August 2016 and November 2018. Data from the randomized, stimulated cycle were part of a larger RCT, which was previously published.Participants/materials, Setting, Methods: The study was conducted at a public fertility clinic at Herlev Hospital, Denmark, including 31 healthy, normo-responding women eligible for IVF treatment. They underwent a natural baseline cycle and were subsequently randomized to receive either LZ 5 mg (n = 16) or placebo (n = 15) daily during ovarian stimulation from cycle day (CD) 2-3 until induction of ovulation. Throughout both cycles, monitoring was performed every third day with transvaginal ultrasound for assessment of follicle count and diameter, and blood analyses for the determination of twelve endocrine and paracrine parameters. A follow-up assessment was performed at CD2-3 in the succeeding cycle. In the randomized part of the study, we determined differences in blood parameters, follicle recruitment, and follicle diameter. In the observational part of the study, we assessed follicle recruitment in between cycles and its correlation to endocrine parameters.Main Results and the Role Of Chance: Letrozole cotreatment significantly suppressed oestradiol (E2) concentrations in the follicular phase (area under the curve (AUC) -58% (95% CI [-70%; -43%], P < 0.001)) and luteal phase (AUC -39% [-63%; -1%], P = 0.046). This had a marked effect on the endocrine and paracrine output with increased follicular phase luteinizing hormone (AUC +37% [3%; 82%], P = 0.033), androstenedione (AUC +36% [6%; 74%], P = 0.016), testosterone (AUC +37% [7%; 73%], P = 0.013) and 17-OH-progesterone (AUC +114% [10%; 318%], P = 0.027). Furthermore, follicle-stimulating hormone (FSH) was increased at stimulation day 5 in the LZ group (P < 0.05). In the luteal phase, increased corpus luteum output was reflected by elevated progesterone (AUC +44% [1%; 104%], P = 0.043), inhibin A (AUC +52% [11%; 108%], P = 0.011), androstenedione (AUC +31% [9%; 58%], P = 0.006) and testosterone (AUC +29% [6%; 57%], P = 0.012) in the LZ group. The altered balance between oestrogens and androgens was reflected in a markedly reduced SHBG concentration in the LZ group throughout the luteal phase (AUC -35% [-52%; -11%], P = 0.009). Endocrine and paracrine parameters were similar between groups at the follow-up visit. Letrozole cotreatment significantly increased the mean number of follicles >16 mm at oocyte retrieval (7.2 vs 5.2, difference: 2.0, 95% CI [0.1; 3.8], P = 0.036), while the mean total number of follicles at oocyte retrieval was the same (23.7 vs 23.5, difference: 0.2 [-5.8; 6.1], P = 0.958), and the mean FSH consumption during the stimulated cycle was similar (1500 vs 1520 IU, difference -20 IU [-175; 136], P = 0.794). Between cycles, the mean antral follicle count at CD2-3 was unchanged (natural cycle 19.0, stimulated cycle 20.9, follow-up cycle 19.7, P = 0.692) and there was no effect of LZ cotreatment on the recruitment of the next follicle cohort (test for interaction, P = 0.821).Limitations, Reasons For Caution: This study included a relatively small, selected group of healthy women with an expected normal ovarian function and reserve, and the effects of LZ may therefore be different in other patient groups.Wider Implications Of the Findings: We confirm some previous findings concerning increased follicle growth and increased endogenous FSH and androgen production, which support the rationale for further studies on the use of LZ cotreatment, for example, as a form of endogenous androgen priming sensitizing the follicle to FSH. Letrozole appears to improve the luteal phase with better stimulation of corpus luteum and progesterone secretion.Study Funding/competing Interest(s): The authors declare no conflicts of interest relating to the present work.Trial Registration Number: NCT02939898. [ABSTRACT FROM AUTHOR]

Study Question: Are GnRH tests and serum inhibin B levels sufficiently discriminating to distinguish transient constitutional delay of growth and puberty (CDGP) from congenital hypogonadotropic hypogonadism (CHH) that affects reproductive health for life?Summary Answer: Both parameters lack the specificity to discriminate CDGP from CHH.What Is Known Already: GnRH tests and inhibin B levels have been proposed to differentiate CDGP from CHH. However, their diagnostic accuracies have been hampered by the small numbers of CHH included and enrichment of CHH patients with more severe forms.Study Design, Size, Duration: The aim of this study was to assess the diagnostic performance of GnRH tests and inhibin B measurements in a large cohort of CHH male patients with the whole reproductive spectrum. From 2008 to 2018, 232 males were assessed: 127 with CHH, 74 with CDGP and 31 healthy controls.Participants/materials, Setting, Methods: The participants were enrolled in two French academic referral centres. The following measurements were taken: testicular volume (TV), serum testosterone, inhibin B, LH and FSH, both at baseline and following the GnRH test.Main Results and the Role Of Chance: Among CHH patients, the LH response to the GnRH test was very variable and correlated with TV. Among CDGP patients, the LH peak was also variable and 47% of CHH patients had peak LH levels overlapping with the CDGP group. However, no patients with CDGP had an LH peak below 4.0 IU/l, while 53% CHH patients had LH peak below this threshold. Among CHH patients, inhibin B levels were also variable and correlated with TV and peak LH. Inhibin B was significantly lower in CHH patients than in CDGP patients but 50% of CHH values overlapped with CDGP values. Interestingly, all patients with CDGP had inhibin B levels above 35 pg/ml but 50% of CHH patients also had levels above this threshold.Limitations, Reasons For Caution: As CHH is very rare, an international study would be necessary to recruit a larger CHH cohort and consolidate the conclusion reached here.Wider Implications Of the Findings: Peak LH and basal inhibin B levels are variable in both CHH and CDGP with significant overlap. Both parameters lack specificity and sensitivity to efficiently discriminate CHH from CDGP. This reflects the varying degree of gonadotropin deficiency inherent to CHH. These two diagnostic procedures may misdiagnose partial forms of isolated (non-syndromic) CHH, allowing them to be erroneously considered as CDGP.Study Funding/competing Interest(s): This study was funded by Agence Française de Lutte contre le Dopage: Grant Hypoproteo AFLD-10 (to J.Y.); Agence Nationale de la Recherche (ANR): Grant ANR-09-GENO-017-01 (to J.Y.); European Cooperation in Science and Technology, COST Action BM1105; Programme Hospitalier de Recherche Clinique (PHRC), French Ministry of Health: PHRC-2009 HYPO-PROTEO (to J.Y.); and Programme Hospitalier de Recherche Clinique (PHRC) "Variété", French Ministry of Health, N° P081216/IDRCB 2009-A00892-55 (to P.C.). There are no competing interests.Trial Registration Number: N/A. [ABSTRACT FROM AUTHOR]

Study Question: What is the peripubertal outcome of recombinant human FSH (r-hFSH) treatment during minipuberty in boys with congenital hypogonadotropic hypogonadism (CHH)?Summary Answer: Sertoli-cell response to r-hFSH, given during the minipuberty of infancy, appears insufficient to maintain Sertoli cell function throughout childhood, as evaluated by inhibin B measurements.What Is Known Already: Severe CHH in boys can be diagnosed during the minipuberty of infancy. Combined gonadotropin treatment at that age is suggested to improve testicular endocrine function and future fertility, yet long-term evidence is lacking.Study Design, Size, Duration: In this retrospective cohort study, we describe five CHH boys treated with r-hFSH in Helsinki University Hospital or Kuopio University Hospital between 2004 and 2018. Immediate follow-up data (0.1-1.4 months after cessation of the gonadotropin therapy) was available for four boys and long-term observations (at the age of 10.0-12.8 years) was available for three boys. As a retrospective control cohort, we provide inhibin B values of eight untreated CHH boys at the age of 12.7-17.8 years.Participants/materials, Setting, Methods: Four patients had combined pituitary hormone deficiency, and one had CHARGE syndrome due to a CHD7 mutation. The patients were treated at the age of 0.7-4.2 months with r-hFSH (3.4 IU/kg-7.5 IU/kg per week in 2 or 3 s.c. doses for 3-4.5 months) combined with T (25 mg i.m. monthly for three months for the treatment of micropenis). Inhibin B was chosen as the primary outcome measure.Main Results and the Role Of Chance: During the r-hFSH + T treatment, inhibin B increased from 76 ± 18 ng/l to 176 ± 80 ng/l (P = 0.04) and penile length increased by 81 ± 50% (P = 0.04). Unexpectedly, two boys with robust inhibin B responses in infancy demonstrated low inhibin B values in peripuberty: declining from 290 ng/l (4 months) to 16 ng/l (12.4 years), and from 207 ng/l (6 months) to 21 ng/l (12.8 years). All boys underwent orchiopexy at 2.0 ± 0.7 years of age. Inhibin B values in long-term follow-up, available for the three boys, did not significantly differ from the untreated CHH controls.Limitations, Reasons For Caution: Limitations of this retrospective study are the small number and heterogeneity of the patients and their treatment schemes.Wider Implications Of the Findings: We describe the first long-term follow-up data on CHH boys treated with r-hFSH and T as infants. The results from this small patient series suggest that the effects of infant r-hFSH treatment may be transient, and further longitudinal studies are required to determine the efficacy of this treatment approach to optimise the fertility potential in this patient population.Study Funding/competing Interest(s): This work was supported by the Finnish foundation for Pediatric Research, the Academy of Finland and the Emil Aaltonen Foundation. The authors have no competing interests.Trial Registration Number: Non-applicable. [ABSTRACT FROM AUTHOR]

STUDY QUESTION What is the daily variation in serum inhibin B (InhB) and anti-Müllerian hormone (AMH) in relation to the LH surge in women of reproductive age. SUMMARY ANSWER AMH is secreted in a biphasic follicular/luteal pattern in women with higher AMH secretion, while InhB secretion is episodic in the early to mid-follicular phase and immediately after the LH surge but not in the luteal phase. WHAT IS KNOWN ALREADY In women of reproductive age with a mean serum AMH >1 ng/ml, levels are highest in Days 2–7 of the cycle. InhB concentrations are highest in the follicular phase of the cycle. STUDY DESIGN, SIZE, DURATION In this cohort study conducted in an academic center, blood samples were collected daily from 20 women during one normal menstrual cycle. PARTICIPANTS/MATERIALS, SETTING, METHODS Regularly menstruating 30- to 40-year-old women had daily serum InhB, AMH, LH and FSH levels measured. Intracycle variability of InhB and AMH were assessed after aligning to the LH surge. MAIN RESULTS AND THE ROLE OF CHANCE When classified into quartiles of AMH concentration, the lowest AMH levels did not vary across the cycle; the highest AMH levels showed a mid-follicular increase, mid-cycle decrease and mid-luteal increase. A surge of InhB was noted following the LH surge in 16/20 cycles. Episodic increases in InhB occurred in 17/20 cycles prior to the LH surge. In the luteal phase, InhB decreased or became undetectable and did not demonstrate episodic secretion. Old and new assays for AMH and InhB were compared in all samples, with the AMH assays demonstrating good correlation (Rsq = 0.9625) but the InhB assays showing less correlation (Rsq = 0.4903). LIMITATIONS, REASONS FOR CAUTION The study population is small and in the mid-to-late reproductive age group. Single daily sampling may not detect more frequent variability (i.e. pulses) in hormone levels. WIDER IMPLICATIONS OF THE FINDINGS These data suggest different regulatory mechanisms for InhB and AMH secretion, and confirm an ‘aging ovary’ pattern of AMH and InhB secretion, which is consistent with decreased ovarian reserve. We also demonstrated comparability of the AMH Gen II assay with the previous version in standard usage but our data raised concerns about comparability of the InhB Gen II assay. STUDY FUNDING/COMPETING INTEREST(S) General Clinical Research Center for phlebotomy work has been supported in part by NIH grant UL1RR024986. Recruitment and data analyses were supported by the Center for Integrated Approaches to Complex Diseases (SD Harlow, Director). The authors report no conflicts of interest. TRIAL REGISTRATION NUMBER N/A. [ABSTRACT FROM AUTHOR]

In this report, we describe a case of a solely inhibin B producing fibrothecoma presenting with secondary amenorrhoea and hot flushes. Typical laboratory findings were an elevated LH, elevated inhibin B, low FSH and low estrogen. The World Health Organization classification of amenorrhoea was not applicable since the combination of low estrogen and low FSH suggested a central cause, whereas actually there was an ovarian cause. With staging laparotomy, a bilateral borderline tumour was detected in combination with a fibrothecoma. This report underpins the concept of inhibin B being a selective FSH secretion inhibitor of ovarian origin. Furthermore, a literature review on these topics is included. [ABSTRACT FROM PUBLISHER]

Background: The significance of polycystic ovarian morphology (PCOM) during adolescence is not clear. The aim of this study was to determine the relationship between PCOM and anti-Müllerian hormone (AMH), inhibin B, testosterone and insulin levels in healthy girls during the second decade of life. We also determined whether AMH could be used as a surrogate marker of PCOM during adolescence. Methods: Seventy-four non-obese adolescents (age range: 13.5-19.75 years old) with regular menstrual cycles participated in this study. Transabdominal ultrasound and blood samples were obtained during the follicular phase. Results: PCOM was present in 33.8% of the subjects. Girls with PCOM had higher AMH levels than girls without PCOM (72.5 ± 6.1 versus 33.4 ± 2.6 pmol/l; P < 0.0001) and lower FSH levels (5.4 ± 0.3 versus 6.2 ± 0.2 mUI/ml; P < 0.036). Similar levels of inhibin B, androgens and LH were observed in girls with and without PCOM. PCOM prevalence and AMH levels were not associated with age (P = 0.745 and 0.2, respectively) or BMI-SDS (P = 0.951 and 0.096, respectively). AMH levels positively correlated with the of 2-5 mm follicle number. AMH levels ≥ 60.15 pmol/l had a sensitivity and specificity of 64.0 and 89.8%, respectively, to diagnose PCOM (area under the curve = 0.873). Conclusions: These data confirm that PCOM in healthy non-hyperandrogenic girls with regular menstrual cycles is prevalent and is not associated with hyperandrogenism. The elevated AMH and lower FSH levels observed in healthy girls with regular menses and PCOM suggest that this ovarian pattern is secondary to a larger number of 2-5 mm follicles. An elevated AMH level is suggestive of the presence of PCOM during adolescence. [ABSTRACT FROM AUTHOR]

BACKGROUND Ovarian function in Turner syndrome (TS) patients depends on the specific karyotype. This retrospective clinical study evaluates the pituitary–gonadal axis during infancy, childhood and adolescence in TS patients according to karyotype and ovarian function. METHODS A cohort of 70 TS patients (0–16 years) followed at a tertiary referral centre for paediatric endocrinology were included. Longitudinal measurements of reproductive hormones (FSH, LH, inhibin B and estradiol) prior to hormonal replacement treatment in 66 patients related to karyotype (A, 45,X; or B, miscellaneous karyotypes) and ovarian function (spontaneous puberty or absent spontaneous puberty) were compared with an age-matched reference range of 2406 healthy Danish females. RESULTS The prevalence of spontaneous puberty was 6% for 45,X and 54% for miscellaneous karyotypes, P = 0.001. In all TS patients, gonadotrophins were higher during infancy and at expected puberty compared with levels at mid-childhood, where 21/25 and 23/27 had FSH and LH levels, respectively, within the reference range. In patients with absent spontaneous puberty, 10/12 had FSH in the reference range during the mid-childhood nadir. 45,X-TS patients had undetectable inhibin B at 0–16 years. Ovarian failure was predicted in 20/20 patients with exclusively undetectable inhibin B, while 9/10 with detectable inhibin B entered puberty spontaneously. Estradiol levels were elevated from 4 to 8 years. CONCLUSIONS Ovarian function in TS patients is associated with the specific karyotype, and multiple undetectable inhibin B values during mid-childhood may predict absence of spontaneous puberty, although the specificity of the test is low. The biphasic age pattern of gonadotrophins was preserved in all patients, and spontaneous gonadotrophins are not useful as a diagnostic marker for TS in girls aged 6–10 years. [ABSTRACT FROM AUTHOR]

BACKGROUND Currently, no published data exist about the gonadal function of children born after ICSI. To evaluate potential risk of testicular seminal dysfunction in boys born to fathers with compromised spermatogenesis, serum inhibin B (as a marker for spermatogenesis) was assessed. METHODS We recruited 50 pubertal adolescents from the oldest cohort of infants born following ICSI. Cross-sectional serum inhibin B levels of all 50 ICSI adolescents, and longitudinal serum inhibin B (assessed at 8 and 14 years) in 25 boys, are reported. RESULTS A statistically significant increase in inhibin B levels was observed between 8 (mean 69 ng/l, SD ± 35) and 14 years (mean 145 ng/l, SD ± 41; P < 0.001). In three quarters of the ICSI boys an increase in serum inhibin B levels of at least 30% between 8 and 14 years was observed. In all but 4 of the 14-year-old ICSI boys serum inhibin B was normal. Serum inhibin B levels in boys from fathers with severe oligozoospermia did not differ from concentrations in boys from fathers without severe oligozoospermia (154 ± 51 and 142 ± 47 ng/l, respectively; P = 0.4). CONCLUSIONS The majority of ICSI boys have a significant increase in serum inhibin B, attaining normal values for pubertal status at the age of 14 years. ICSI adolescents from fathers with severely compromised spermatogenesis do not have lower inhibin B levels than those with fathers with normal spermatograms. Further follow-up of the spermatogenic potential of ICSI teenagers up to young adulthood is mandatory to confirm a normal reproductive capacity. [ABSTRACT FROM AUTHOR]

Objective: The aim of this study was to evaluate whether values of FSH, LH, estradiol, anti-Müllerian hormone (AMH), inhibin B, antral follicle count (AFC) and ovarian volume (OV) determined on day 7 of the hormone-free interval are similar to values measured on days 2-5 of two subsequent natural menstrual cycles. In addition, values measured on day 7 of the hormone-free interval were examined for the purpose of predicting values measured on days 2-5 during the second natural cycle. Methods: In this study, 25 women using hormonal contraception provided a blood sample and underwent transvaginal ultrasound measurements on day 7 of the hormone-free interval and on cycle days 2-5 of two subsequent natural cycles. Changes were compared by repeated measures ANOVA and multivariate linear regression was used for prediction purposes. Results: Mean (SD) age of the participants was 26.3 (6.2) years. Overall significant decreases in FSH and inhibin B and significant increases in AMH, AFC and ovarian volume values were measured after discontinuation of hormonal contraception (P < 0.001, P = 0.04, P = 0.01, P < 0.001 and P = 0.004, respectively). Significant changes occurred both from day 7 of the hormone-free interval to natural cycle 1 as well as from natural cycle 1 to natural cycle 2. FSH, AMH and AFC values measured during days 2-5 of natural cycle 2 could be predicted by the corresponding values measured on day 7 of the hormone-free interval. Conclusion: Hormonal and ultrasound markers of ovarian function in hormonal contraception users measured at the end of the hormone-free interval do not seem to represent subsequent natural early follicular phase values. However, these values can, in some cases (FSH, AMH and AFC), be used to predict early follicular phase values using calculated prediction equations, which need to be validated in future research. [ABSTRACT FROM AUTHOR]

Background: Inhibin B (Inh B) is produced by pre-antral and early antral follicles whereas estradiol (E(2)) is a product of follicles undergoing antrum formation. This temporal distinction is evident in the patterns of Inh B and E(2) release earlier and later during the follicular phase of the menstrual cycle, respectively. However, in previous studies of women with polycystic ovary syndrome (PCOS) and normal controls, release of these granulosa cell (GC) products appears to be simultaneous in response to FSH stimulation. In order to reconcile these disparate findings, we conducted dose-response studies in both PCOS women and normal controls to determine whether GC product responses were due to the amount of FSH administered. In addition, we compared FSH-stimulated responses in PCOS women at various stages of recovery following ovarian suppression with a long-acting GnRH agonist to examine whether Inh B and E(2) responses reflected the level of ovarian follicle activity (i.e. circulating E(2) levels).Methods: Women with PCOS, 18-35 years (n = 23), and normal ovulatory controls, 18-35 years (n = 10) were recruited for study. Dose-responses were assessed over 24 h following intravenous administration of 0 (saline), 37.5, 75 and 150 IU of recombinant human FSH (r-hFSH) in PCOS and normal women. In addition, E(2) and Inh B responses to 150 IU of r-hFSH were assessed at baseline and 4, 6 and 8 weeks following suppression of ovarian steroidogenesis by a long-acting GnRH agonist in PCOS women.Results: In PCOS women and normal controls, serum Inh B and E(2) exhibit similar and simultaneous dose-responsiveness to FSH stimulation. During recovery from ovarian suppression, basal and stimulated Inh B release appear to be restored earlier than that of E(2) in PCOS women.Conclusions: These findings are consistent with the notion that, in PCOS women, the level of ovarian follicle activity largely determines the earlier release of Inh B compared with E(2). [ABSTRACT FROM AUTHOR]

Background: The aim was to evaluate the role of serum inhibin A and activin A in the prediction of the outcome of women with 'pregnancies of unknown location' (PULs). Methods: Serum human chorionic gonadotrophin (hCG), progesterone, inhibin A and activin A levels were measured at 0 and 48 h. Differences in the mean levels and the change in levels over 48 h expressed as a ratio (48/0 h) were examined between the three outcome groups--failing PUL, intrauterine pregnancy (IUP) or ectopic pregnancy. Variables were incorporated into logistic regression models to predict the pregnancy outcomes, which were evaluated using receiver operator characteristic curves. Results: One hundred and forty-one women were classified as PULs: 67 failing PULs (47.5%), 58 IUPs (41.1%) and 16 ectopic pregnancies (11.4%). Activin A levels were not significantly different between the three outcome groups. Inhibin A levels were significantly lower in failing PULs. The logistic regression model based on serum inhibin levels gave an area under the curve (AUC) of 0.88 for failing PUL, 0.87 for IUP and 0.60 for ectopic pregnancy. The model based on serum activin levels gave an AUC of 0.61 for failing PUL, 0.64 for IUP and 0.51 for ectopic pregnancy, and the model based on serum hCG levels gave an AUC of 0.95 for failing PUL, 0.97 for IUP and 0.67 for ectopic pregnancy. Conclusions: Serum activin A levels at 0 and 48 h are not helpful in predicting the outcome of PULs. Although serum inhibin A levels may be of use in the prediction of failing PULs and IUPs in the PUL populations, they do not perform as well as serum hCG levels. [ABSTRACT FROM AUTHOR]

BACKGROUND: Laparoscopic ovarian diathermy (LOD) frequently induces ovulation in patients with polycystic ovary syndrome (PCOS). The mechanism by which this effect occurs remains largely unexplained. The aim of this study was to measure changes in inhibin B production in response to LOD to see whether this could explain the mechanism of action of LOD. METHODS: This prospective study included 50 anovulatory women with PCOS. All women underwent LOD. Blood samples were collected before and after LOD to measure plasma concentrations of inhibin B, gonadotrophins and androgens. RESULTS: The pre-operative median plasma concentration of inhibin B was 110.0 pg/ml (range 19.0–567.0 pg/ml). There was a statistically significant inverse correlation (r = –0.286; P < 0.05) between body mass index (BMI) and inhibin B. Non-obese women with PCOS (BMI ≤ 30 kg/m2; n = 37) displayed significantly (P < 0.05) higher plasma inhibin B concentrations [122.0 pg/ml (range 19.0–567.0 pg/ml)] compared with those [51.0 pg/ml (range 27.0–201.0 pg/ml)] of obese PCOS women (BMI > 30 kg/m2; n = 13). Following LOD, 39 women ovulated. No statistically significant change of inhibin B after LOD was observed in the overall group of women with PCOS or in the subgroup of non-obese PCOS women with higher pre-operative inhibin B. CONCLUSIONS: The lack of any change of inhibin B after LOD makes it unlikely that this hormone has any role to play in the mechanism of action of LOD. [ABSTRACT FROM AUTHOR]

BACKGROUND: To investigate whether second trimester serum inhibin levels differ in pregnancies conceived by assisted reproduction technology (ART). METHODS: In Israel, serum samples from twin pregnancies were obtained for inhibin testing from women either referred for routine ultrasound monitoring, follow up after multi-fetal reduction or amniocentesis, largely for advanced maternal age. In the UK, inhibin had been tested prospectively in singleton and twin pregnancies of women having routine Down’s syndrome (DS) screening. Results were available from 207 ART pregnancies: 170 singletons and 37 twins. This includes 15 twins from Israel, known to have been reduced from triplets to twins. Comparison was made with 4384 spontaneous pregnancies: 4334 singletons and 50 twins. Results were expressed in multiples of the gestation-specific median (MoM) for normal spontaneous pregnancies. RESULTS: In ART singletons, the median maternal inhibin level was higher (1.11 MoM) than in spontaneous singletons (0.99 MoM, P < 0.001, two-tail Wilcoxon Rank Sum Test). In twins, there was no material difference between ART and spontaneous pregnancies with medians of 1.98 and 2.18 MoM, respectively (P = 0.62). There was no effect of multi-fetal reduction, with medians of 1.76 and 1.81 MoM in reduced and non-reduced twins, respectively (P = 0.46). CONCLUSION: It appears that serum inhibin levels are increased on average in ART singletons but not in ART twin pregnancies. More data will be needed before deciding whether risk calculation parameters need to be altered when using inhibin for DS screening in pregnancy. [ABSTRACT FROM AUTHOR]

BACKGROUND: We aimed to examine the serum levels of inhibin A, vascular endothelial growth factor (VEGF), tumour necrosis factor α (TNFα), estradiol (E2) and progesterone levels after triggering of final oocyte maturation with GnRH agonist compared with HCG in patients with polycystic ovaries (PCO) and to investigate the relationship between these markers and ovarian hyperstimulation syndrome (OHSS). METHODS: Twenty-eight patients with PCO, undergoing controlled ovarian hyperstimulation with FSH and GnRH antagonist for IVF–embryo transfer treatment, were randomized for triggering of final oocyte maturation with GnRH agonist (GnRH agonist group, n = 15) or HCG (HCG group, n = 13). Blood samples were obtained on the day of randomization and thereafter every 2–7 days. Serum levels of inhibin A, VEGF, TNFα, E2 and progesterone, the incidence of OHSS, ovarian size and pelvic fluid accumulation were evaluated. RESULTS: Serum inhibin A, E2 and progesterone levels were significantly lower in the GnRH agonist group compared with the HCG group, particularly on the day of embryo transfer (P < 0.0001). Serum VEGF and TNFα levels were similar between the two groups. Four patients in the HCG group developed severe OHSS, whereas no patient had any symptoms or signs of OHSS in the GnRH-agonist group (P < 0.05). CONCLUSIONS: In patients with PCO treated with FSH/GnRH antagonist, final oocyte maturation with GnRH agonist instead of HCG reduces significantly inhibin A, E2 and progesterone levels during the luteal phase. This phenomenon reflects the inhibition of the corpus luteum function and may explain, at least in part, the mechanism of OHSS prevention in high-risk patients. Our results do not support a crucial role for VEGF or TNFα in OHSS. [ABSTRACT FROM AUTHOR]

BACKGROUND: Premature ovarian failure (POF) is characterized by hypergonadotropic amenorrhoea before the age of 40. Inhibin α-subunit (INHα) gene is proposed as a candidate gene due to its role in negative feedback control of FSH. METHODS: Polymorphism –16C>T of INHα gene was studied in 61 POF patients and 82 controls above 40 years old (C > 40). Substitution 769G>A was studied in 59 POF patients, 76 C > 40 and 73 controls below 40 years old (C < 40). RESULTS: No significant difference in risk of POF development for –16T allele was found when comparing idiopathic POF (I-POF) with C > 40 (Odds ratio = 1.46; 95% confidence interval = 0.63–3.19). Implication of –16C>T polymorphism in serum inhibin levels was analysed in 46 controls, and no significant differences (P > 0.05) were found between CC and CT + TT genotype groups when comparing either mid-follicular phase Pro-αC and inhibin B values or mid-luteal phase Pro-αC and inhibin A values. Heterozygosity for substitution 769G>A was found in 1 of 59 POF woman, 2 of 76 C > 40 and 6 of 73 C < 40. Presence of this substitution in a relevant number of control subjects is herein described for the first time. CONCLUSION: Our results indicate that –16C>T and 769G>A variants in INHα gene may not be associated to POF disease. [ABSTRACT FROM AUTHOR]

BACKGROUND: The association of normal serum levels of immunoassayable gonadotrophins with anovulation during lactational amenorrhoea (LA) has not been fully explained. METHODS: Serum FSH polymorphism was analysed in 10 women during LA between days 60 and 70 post-partum and again, in the mid-follicular phase (MFP), after resuming menstrual cyclicity. FSH microheterogeneity was characterized according to charge, using preparative isoelectric focusing, and according to the inner structure of carbohydrate chains, using lectin chromatography. RESULTS: A significantly higher proportion of FSH charge isoforms isolated below pH 4.10 and a lower proportion of FSH isoforms bearing highly branched oligosaccharides were observed during LA when compared to MFP. Further analysis with higher resolution showed that FSH charge isoforms, isolated in the lower pH range in LA, corresponded to FSH molecules bearing highly branched and biantennary oligosaccharides. FSH isoforms bearing hybrid-type oligosaccharides were only present during LA. The circulating FSH isoform mix was significantly less bioactive in LA than in MFP. LA is characterized by a more acidic mix of FSH isoforms, containing hormone bearing less processed oligosaccharides, with decreased biopotency in comparison with the follicular phase. CONCLUSIONS: This FSH microheterogeneity may be one of the critical factors contributing to incomplete follicular development and anovulation during LA. [ABSTRACT FROM AUTHOR]

BACKGROUND: Comparisons of follicular development and hormonal profile in the same women during and after lactational amenorrhoea (LA) are scarce. We report follicular growth, pituitary and ovarian hormone serum levels in the same women during LA and in follicular phases after resumption of menstrual cyclicity. METHODS: Serum samples were obtained from 10 women during LA between days 60 and 89 post-partum and between days 1 and 4 (early follicular phase; EFP) and 7 and 10 (mid-follicular phase; MFP) of the second and third cycles after LA. RESULTS: The number of follicles >3 mm and diameter of the largest follicle were significantly higher during LA when compared to EFP and MFP. Serum levels of inhibin B were similar in LA and EFP and increased significantly in MFP. Pro-αC was significantly higher in EFP than in LA and MFP. Estradiol was similar during all stages. In comparison with EFP and MFP, LA is associated with higher prolactin levels, normal or slightly elevated gonadotrophins and increased number and size of follicles without a parallel increase in estradiol, inhibin B and Pro-αC. CONCLUSIONS: During LA, there is a profound dissociation between follicular growth and follicular endocrine activity, which suggests an alteration in the stimulus–response relationship at the follicular level. [ABSTRACT FROM AUTHOR]

BACKGROUND: FSH hypersecretion occurs in mothers of dizygotic (DZ) twins. Twinning is inherited via both sexes and transmitted through the female. FSH hypersecretion may thus occur in male DZ twins. METHODS: We assayed FSH and its counter-regulatory hormone, Inhibin B, in 108 adult male DZ and 100 monozygotic (MZ) twins (as controls) and compared our results to published norms. RESULTS: Inhibin B was elevated and higher in DZ compared with MZ twins with similar FSH. CONCLUSION: The normal FSH: Inhibin B endocrine feedback axis is different in adult male DZ twins. This contributes to the theory that the answer to human DZ twinning lies in the actions of FSH and Inhibin, and in their mutual interaction. [ABSTRACT FROM AUTHOR]

BACKGROUND: We evaluated basal and dynamic hormonal markers [(FSH, inhibin B, estradiol and anti-Mullerian hormone (AMH)] during the follicular phase and luteal phase of the menstrual cycle and ultrasonic ovarian morphology as predictors of IVF outcome. METHODS: Fifty-six women, aged <38 years, with normal day 3 FSH levels were included prospectively. Serum estradiol, inhibin B and AMH were measured before and 24 h after administration of 300 IU of recombinant FSH on cycle day 34 and during the luteal phase. Ovarian volume and antral follicle count (AFC) were evaluated on cycle day 34. The predictive value of oocyte number and pregnancy were assessed using uni- and multivariate analysis. RESULTS:Poor responders (<6 oocytes) had significantly lower luteal AMH levels, while high responders (>20 oocytes) had significantly higher AFC, AMH and luteal stimulated inhibin B and estradiol than normal responders. Multivariate regression analyses showed that the best models for predicting oocyte number included AFC, follicular phase AMH and stimulated inhibin B. Only AMH showed a significant difference between pregnant and non-pregnant women at both cycle phases. CONCLUSIONS: In young women (<38 years), AFC or basal AMH and stimulated inhibin B predict ovarian response for IVF. The only predictor for pregnancy is follicular or luteal phase AMH. [ABSTRACT FROM AUTHOR]

BACKGROUND: New biological markers of male fecundity are needed for use in large-scale epidemiological studies. We studied the association between male inhibin B and fecundability. METHODS: Four hundred and thirty Danish couples without previous reproductive experience were followed from termination of contraception until pregnancy or for a maximum of six menstrual cycles. At enrolment we obtained semen samples (n = 418) and blood samples to measure reproductive hormones, including inhibin B (n = 343). RESULTS: The fecundability odds ratio for an increment of male inhibin B by 1 log pg/ml was 1.428 (95% confidence interval 1.022–1.994), adjusted for factors influencing the crude estimate. Only inhibin B values below 100 pg/ml were strongly related to fecundability. We designed a receiver operating characteristic curve based on the 29 males with serum inhibin B #100 pg/ml. The area under the curve (AUC) for inhibin B was 0.787 and the corresponding AUCs for sperm density and FSH were 0.913 and 0.800, respectively. CONCLUSION: Serum inhibin B may be a reliable marker of male fecundity for epidemiological research and may have some advantages over sperm density. Our findings do not support the replacement of sperm density by male inhibin B when obtaining sperm data is an option. [ABSTRACT FROM AUTHOR]

BACKGROUND: We sought to identify indicators of antral follicle count which would be serviceable to clinicians seeking to estimate the number of ovarian follicles without relying on sonographic counts. METHODS: We examined the relations of chronological age and four potential indicators of ovarian ageovarian volume, FSH, dimeric inhibin B and estradiolto antral follicle count in 176 recently pregnant women. We identified the regression models which best predict low antral follicle count (=10 follicles). RESULTS: Chronological age, ovarian volume, FSH and inhibin B were each significantly associated with antral follicle count. Fifty-three (30.1%) women had =10 antral follicles. In the total sample, at the cutpoint corresponding to 80% sensitivity, the positive predictive value for a regression model with all four variables was 60%. All regression models performed less well in women <35 years (13.9% with low count) than in women =35 years (52.0% with low count). In older women, the positive predictive value for the model with all four variables was 79%, compared with 60% for a model with chronological age alone. CONCLUSIONS: Our models provide a basis for advising women aged =35 years who are either trying to conceive or wish to learn whether they may postpone childbearing. [ABSTRACT FROM AUTHOR]

BACKGROUND: Microdissection testicular sperm extraction (TESE) has provided new hope for successful sperm retrieval to patients with Sertoli cell-only syndrome (SCO). We determined expression of the inhibin a subunit, glial cell line-derived neurotrophic factor (GDNF) and stem cell factor (SCF) in Sertoli cells obtained from patients with SCO immunohistochemically and compared expression rates with rates of microdissection TESE sperm retrieval. METHODS: Testicular biopsy specimens were obtained from 52 men with non-obstructive azoospermia who underwent microdissection TESE and were diagnosed with SCO by histological analysis. RESULTS: All specimens showed intense staining for the inhibin a subunit. Moderate or intense staining for GDNF was observed in 65.8% of specimens. All but one showed moderate or intense staining for SCF. Among specimens negative for GDNF, the sperm retrieval rate was significantly higher (100%) for specimens with intense staining for SCF than for specimens with no or moderate staining (30.7%) (P<0.05) for SCF. CONCLUSION: GDNF expression differs among patients with SCO. The sperm retrieval rate was high in cases of no staining for GDNF and intense staining for SCF. [ABSTRACT FROM AUTHOR]

BACKGROUND: Our aim was to compare the intercycle reproducibility of serum anti-Mllerian hormone (AMH) measurements with that of other markers of ovarian follicular status. METHODS: Forty-seven normo-ovulatory, infertile women underwent serum AMH, inhibin B, estradiol and FSH measurements and early antral follicle (212?mm in diameter) counts by transvaginal ultrasound on cycle day 3 during three consecutive menstrual cycles. Reproducibility of measurements was estimated using intra-class correlation coefficient (ICC) calculation. We also assessed the number of replicate measurements theoretically needed to reach satisfactory reliability of results. RESULTS: Serum AMH showed significantly higher reproducibility (ICC, 0.89; 95% confidence interval, 0.830.94) than inhibin B (0.76; 0.660.86; P<0.03), estradiol (0.22; 0.030.41; P<0.0001) and FSH levels (0.55; 0.390.71; P<0.01), and early antral follicle counts (0.73; 0.620.84; P<0.001), and reached satisfactory reliability with a single measurement. CONCLUSIONS: The improved cycle-to-cycle consistency of AMH as compared with other markers of ovarian follicular status is in keeping with its peculiar production by follicles at several developmental stages and further supports its role as a cost-effective, reliable marker of ovarian fertility potential. [ABSTRACT FROM AUTHOR]

BACKGROUND: Phthalates are used in personal and consumer products, food packaging materials, and polyvinyl chloride plastics and have been measured in the majority of the general population of the USA. Consistent experimental evidence shows that some phthalates are developmental and reproductive toxicants in animals. This study explored the association between environmental levels of phthalates and altered reproductive hormone levels in adult men. METHODS: Between 1999 and 2003, 295 men were recruited from Massachusetts General Hospital. Selected phthalate metabolites were measured in urine. Linear regression models explored the relationship between specific gravity-adjusted urinary phthalate monoester concentrations and serum levels of reproductive hormones, including FSH, LH, sex hormone-binding globulin, testosterone, and inhibin B. RESULTS: An interquartile range (IQR) change in monobenzyl phthalate (MBzP) exposure was significantly associated with a 10% [95% confidence interval (CI): -16, -4.0] decrease in FSH concentration. Additionally, an IQR change in monobutyl phthalate (MBP) exposure was associated with a 4.8% (95% CI: 0, 10) increase in inhibin B but this was of borderline significance. CONCLUSIONS: Although we found associations between MBP and MBzP urinary concentrations and altered levels of inhibin B and FSH, the hormone concentrations did not change in the expected patterns. Therefore, it is unclear whether these associations represent physiologically relevant alterations in these hormones, or whether they represent associations found as a result of conducting multiple comparisons. [ABSTRACT FROM AUTHOR]

BACKGROUND: The aim of this study was to investigate the predictive accuracy and clinical value of performing either a single or a repeated clomiphene citrate challenge test (CCCT) in predicting poor response in IVF, compared to that of currently used basal ovarian reserve markers. METHODS: Sixty-three patients undergoing their first IVF treatment were prospectively included. After measurement of basal markers on cycle day 3 (cd3) [FSH, inhibin B and antral follicle count (AFC)], a CCCT was performed. FSH and inhibin B levels were measured on day 10 (cd10). A second CCCT was performed after a washout period of one cycle. In all patients the tests were followed by an IVF treatment. Poor response (<4 oocytes or cancellation due to impaired (<3 follicles) or absent follicular growth) was used as primary outcome measure. RESULTS: Both the single as well as the repeated CCCT markers had a rather good discriminative potential for the prediction of poor response (area under the receiver operating characteristic curve (ROCAUC): FSH cd10 = 0.79, inhibin B cd10 = 0.79, mean FSH cd10 = 0.82 and mean inhibin B cd10 = 0.88). This compared well with the performance of the basal markers (FSH 0.82, inhibin B 0.72 and AFC 0.83). In a multivariate analysis on only the basal variables, FSH cd3 and AFC were selected (ROCAUC 0.89). Only stepwise forward analysis on the repeated CCCT variables revealed a better discriminating potential for the prediction of poor response (ROCAUC 0.92). At a specificity level of ∼0.97, sensitivity and the positive predictive value were marginally improved in the CCCT models. CONCLUSIONS: Performing a CCCT (single or repeated) has a rather good ability to predict poor response in IVF. However, it appears that the predictive accuracy and clinical value of the CCCT is not clearly better than that of basal FSH in combination with an AFC. Therefore, the use of the CCCT as a predictor of outcome in IVF should not be advocated. [ABSTRACT FROM AUTHOR]

BACKGROUND: Serum FSH elevations and decreases in inhibin B have been consistently demonstrated in the early follicular phase of cycles in women of advanced reproductive age. However, secretory products of the dominant follicle (estradiol and inhibin A) in the serum of older ovulatory women are maintained at levels similar to those of their younger counterparts. The goal of this investigation was to determine if ovarian secretory capacity is dependent on relative FSH levels and if basal measures of ovarian reserve reflect ovarian secretory capacity. METHODS: We administered equivalent low, but effective doses of recombinant FSH for 5 days to a group of older subjects (40–45 years, n=9) and younger controls (20–25 years, n=10) after pituitary suppression with a GnRH agonist. Outcome measures included follicular development as determined by serial transvaginal ultrasound examinations and serum levels of estradiol, inhibin A and inhibin B. RESULTS: Serum levels of estradiol and inhibin A were not statistically different between the two groups, while the number of large follicles formed was greater in the younger subjects. Basal parameters of ovarian reserve were not significantly correlated with ovarian secretory capacity, but did correlate with the number of follicles recruited in response to low-dose FSH. CONCLUSIONS: By providing equivalent serum levels of FSH in older and younger reproductive aged women, this study demonstrates that the secretory capacity of recruited follicles is maintained in older reproductive aged women. [ABSTRACT FROM AUTHOR]

BACKGROUND: Inhibin-B decreases and activin increases FSH secretion in adults. We investigated whether an FSHinhibin/activin feedback loop exists before or during puberty. METHODS: FSH secretion was stimulated with 10?g/kg leuprolide acetate (GnRH agonist) in 18 girls, ages 1.013.2 years, and 11 boys, ages 8.915.2 years, with variations in pubertal development, and in five normal 9- to 10-year-old girls. Blood, obtained at 0, 0.5, 1, 2, 4, 8, 12, 16, 20 and 24?h after GnRH agonist, was analysed for LH, FSH, activin-A, inhibin-A, inhibin-B, follistatin 288 and estradiol/testosterone. RESULTS: FSH increased within 30?min of GnRH agonist administration with a peak greater in girls than boys (P=0.0006). Baseline inhibin-B was greater in boys than girls (P=0.01), while baseline activin-A concentrations were greater in girls. GnRH agonist-stimulated FSH increased inhibin-B in girls by 8?h and in boys by 20?h (P<0.05), but did not affect activin-A. Inhibin-B increases were seen only in girls older than 5 years. CONCLUSIONS: An inhibin-BFSH feedback loop exists prior to the onset of puberty in girls older than 5 years. Sex differences in activin-A and inhibin-B concentrations may be responsible for sex differences in serum FSH concentrations. [ABSTRACT FROM AUTHOR]

BACKGROUND: Clinically, premature ovarian failure (POF) is defined as unexplained amenorrhoea (>6 months) with a high FSH level (>40 IU) before the age of 40 years. POF is a heterogeneous genetic disease with unknown aetiology. Inhibin and activin regulate the FSH level by their opposing actions and thus have been considered as strong candidate genes in the aetiology of POF. METHODS: We have screened inhibin genes in patients with POF (n=80), primary amenorrhoea (n=33) and secondary amenorrhoea (n=4). RESULTS: INHβB and INHβA genes do not show any association with ovarian failure. We found the Ala257Thr missense mutation in INHα gene with high statistical significance in POF (nine out of 80, 11.2%) (Fisher's exact test, P=0.0005), primary amenorrhoea (three out of 33, 9.1%) (Fisher's exact test, P=0.014) and secondary amenorrhoea (two out of four, 50%) (Fisher's exact test, P=0.001) with complete absence of this mutation in controls (none out of 100). CONCLUSION: The INHα gene is a strong candidate gene for ovarian failure. Mutations in INHβB and INHβA genes are not associated with ovarian failure. [ABSTRACT FROM AUTHOR]

BACKGROUND. In vitro continuous stimulation of Sertoli cells with FSH leads to a desensitization of these cells to FSH action. To evaluate the presence of a desensitization of FSH receptor on Sertoli cells in vivo, we performed a controlled clinical study in 97 men affected by severe oligozoospermia. METHODS. On the basis of FSH and inhibin B plasma concentrations, these subjects were divided into three groups: group A, 33 subjects with high FSH and low inhibin B plasma levels; group B, 32 subjects with high FSH plasma levels and inhibin B concentrations at the lower limit of the normal range; and group C, 32 subjects with normal FSH and inhibin B plasma levels. Patients with high FSH plasma levels (groups A and B) were prospectively randomized into two subgroups, called A1, A2, B1 and B2. Patients of groups A1 and B1 were treated with a GnRH agonist, leuprolide acetate, to induce a hypogonadotrophic state and then were treated with recombinant human FSH (r‐hFSH; 100 IU/day) and hCG (2000 IU/twice a week) for 2 months. Subjects of groups A2, B2 and C were treated only with r‐hFSH for the same period. RESULTS. In patients of group A1, inhibin B remained unmodified during the whole period of study, whereas in subjects of group B1, we observed a significant reduction of this hormone during the hypogonadotrophic period and then an increase of inhibin B plasma levels that were higher that those observed before therapy. In patients of groups A2 and B2, FSH treatment did not induce a significant increase in inhibin B concentrations. In patients of group C, FSH induced a significant increase in inhibin B plasma levels. CONCLUSIONS. In infertile men, suppression of the high endogenous levels of plasma FSH associated with much lower exogenous FSH levels is able to evoke higher inhibin B production, which may indicate improved Sertoli cell function and the possibility that this could have a positive effect on spermatogenesis. [ABSTRACT FROM AUTHOR]

BACKGROUND: This study was designed to assess prospectively the intercycle variability (ICV) of basal FSH (bFSH), clomiphene citrate challenge test (CCCT) (analysis of the CCCT was performed by the parameter: ∑bFSH &plus; sFSH) and exogenous FSH ovarian reserve test (EFORT) (analysis of the EFORT included the following parameters: estradiol (E2) increment and inhibin B increment 24 h after administration of FSH), and secondarily to assess the influence of the variability of these ovarian reserve tests. METHODS: Eighty‐five regularly menstruating patients, aged 18–39 years, participated in this prospective study, randomized, by a computer‐designed four‐blocks system into two groups. Forty‐three patients underwent a CCCT, and 42 patients underwent an EFORT. Each test was performed 1–4 times in subsequent cycles, one test per cycle. During the first three cycles, patients were treated with intrauterine insemination (IUI). Follicle number and oocyte yield during IVF ovarian stimulation in the fourth cycle were taken as measures for ovarian reserve. RESULTS: The per cycle variance of bFSH ranged from 1.8 to 4.4 (maximum to minimum ratio of 2.44, P < 0.0001), while that of CCCT ranged from 21.3 to 70.6 (3.31, P < 0.0001). No significant change in per cycle variance was found for the E2 increment (1.25, P > 0.2) and inhibin B increment (1.31, P > 0.2), which were the EFORT parameters. A large ICV of CCCT and bFSH test results was strongly associated with lower ovarian reserve. CONCLUSIONS: Our study shows that the ICV of the inhibin B increment and the E2 increment in the EFORT is stable in consecutive cycles, which indicates that this reproducible test is a more reliable tool for determination of ovarian reserve than bFSH and CCCT. Women with limited ovarian reserve show a strong ICV of bFSH and FSH response to clomiphene citrate. [ABSTRACT FROM AUTHOR]

BACKGROUND: This study was designed to compare endocrine tests [clomiphene citrate challenge test (CCT), exogenous FSH ovarian reserve test (EFORT) and basal FSH, basal estradiol (E2) and basal inhibin B as an integral part of all CCT and EFORT], with respect to their ability to estimate the stimulable cohort of follicles in the ovaries (ovarian capacity) and to analyse which test or combination of tests would give the best prediction of ovarian capacity. METHODS: A total of 110 regularly menstruating patients, aged 18-39 years, participated in this prospective study, randomized by a computer-designed 4-block system study into two groups. Fifty-six patients underwent a CCT, and 54 patients underwent an EFORT. In all patients, the test was followed by an IVF treatment. The result of ovarian hyperstimulation during IVF treatment, expressed by the total number of follicles, was used as gold standard. RESULTS: Univariate linear regression analysis showed that the best correlation with the number of follicles after ovarian hyperstimulation (Y) is found by the inhibin B increment (InhB incr.) in the EFORT (Y = 3.957 + 0.081 × InhB incr. (95% CI 0.061-0.101); r = 0.751; P < 0.001). Multiple linear regression analysis showed a significant contributing value of the variables basal FSH, E2 increment of the EFORT and inhibin B increment to the basic model with the variable age. The best prediction of ovarian capacity (Y) was seen when E2 increment and inhibin B increment were used simultaneously in a stepforward multiple regression prediction model [Y = 2.659 + 0.052 × InhB incr. (0.026-0.078) + 0.027 × E2 incr. (95% CI 0.012-0.054); r = 0.796; P < 0.001]. The CCT could not be used in a prediction model. CONCLUSIONS: The EFORT is the endocrine test which gives the best prediction of ovarian capacity. [ABSTRACT FROM AUTHOR]

BACKGROUND: The purpose of this study was to compare the predictive capacity of several markers of reproductive age in normal women. METHODS: Healthy female volunteers (n = 162) aged 2546 years with proven, normal fertility and regular menstrual cycles were recruited. In this selected group, chronological age was assumed to approximate reproductive age and, therefore, was taken as the proxy-variable for reproductive age. The number of antral follicles with 210 mm diameter, total ovarian volume, total follicular volume, mean follicular volume, and volume of either the smallest or largest ovary were estimated by transvaginal sonography of the ovaries. Serum levels of early follicular FSH, estradiol and inhibin B, as well as the response of estradiol and inhibin B to exogenous GnRH agonist administration (GAST), were also evaluated. RESULTS: Regression analysis revealed that the antral follicle number showed the highest correlation with age (r = 0.68, P = 0.001), and explained 46% of its variance. All other variables, except inhibin B, were moderately correlated with age. Responses of estradiol and inhibin B to the GnRH agonist were moderately correlated with age, but highly correlated with the number of antral follicles. CONCLUSIONS: It is concluded that the number of antral follicles has the closest association with chronological age in normal women with proven fertility. As stimulated estradiol and inhibin B clearly reflect the size of the antral follicle cohort, the GAST may be considered the second best single test to predict reproductive age. [ABSTRACT FROM AUTHOR]

Background: The objective of this study was to confirm the source and study the acute changes and relationship between inhibins and FSH at surgical menopause.Methods: Regularly cycling women (42-47 years; n = 10) undergoing bilateral oophorectomy for non-ovarian pathology were recruited for this study. One blood sample was taken before surgery and after removal of the ovaries, samples were taken every 15 min up to 1 h, hourly up to 6 h, after 12 h and daily during the hospital admission (3 days).Results: There were five women in the follicular phase and five women in the luteal phase of the cycle. For women in both phases, levels of inhibin A, inhibin B, estradiol (E(2)) and progesterone decreased after the removal of the ovaries. Serum FSH levels started to rise after 12 h in both follicular and luteal phase women after the surgical menopause. Correlation analysis showed that inhibin A and E(2) were significantly negatively correlated in both phases with FSH concentration. Inhibin B had a negative correlation in the follicular phase and progesterone had a negative correlation in the luteal phase.Conclusions: This study showed that ovarian inhibin A and B were cleared from the circulation within 12 h of oophorectomy, whereas E(2) and progesterone remain in the circulation for longer. Negative correlation between FSH, inhibin A and inhibin B suggests that inhibins may contribute to the observed early rise in FSH after the surgical menopause. [ABSTRACT FROM AUTHOR]

Background: Premature ovarian failure (POF) is a secondary hypergonadotrophic amenorrhoea affecting 1-3% of females, whose aetiology is almost unknown. However, inhibin alpha gene (INHalpha) has recently been indicated as candidate in POF pathogenesis.Methods: We analysed patients affected by POF (n = 157) for the missense mutation (769G-->A transition) in the exon 2 of the INHalpha gene. The same analysis was carried out on early menopause (EM) (n = 36) and primary amenorrhoea (n = 12) patients.Results: The incidence of the mutation was significantly more frequent within both POF (7/157, 4.5%) (Fisher's exact test, P = 0.030) and primary amenorrhoea (3/12, 25%) (Fisher's exact test, P < 0.001) patients, compared with the control population of women (0/100), who experienced physiological menopause. No mutation was found in EM patients. Furthermore, the likelihood of finding the mutation was statistically significant in familial (5/65; 7.7%) (Fisher's exact test, P < 0.01) but not in sporadic (2/92; 2.2%) (Fisher's exact test, P = not significant) POF, compared with the control group. The analysis of pedigrees showing the inheritance of the 769G-->A mutation and POF strengthens the concept of the disease heterogeneity, since the POF phenotype was not always associated with the mutation. Moreover, a higher prevalence of the C allele of a single nucleotide polymorphism (129C-->T), located in the 5'-UTR of the INHalpha gene, was observed in POF patients (80.3%) than in the control group (66.7%) (Fisher's exact test, P = 0.014).Conclusion: These data strengthen the concept of the INHalpha gene as a candidate for ovarian failure. [ABSTRACT FROM AUTHOR]

We have measured secretory patterns of inhibin A, B, total α inhibin, pro-αC inhibin and oestradiol in women following pituitary suppression who were randomised into two groups to receive either urinary gonadotrophin (25:75 IU/ampoule of luteinizing hormone (LH) and follicle stimulating hormone (FSH; Normegon; n = 11) or recombinant (r)FSH (75 IU/ampoule of FSH alone, n = 16). The women were of similar age (~33 years) and length of infertility (~4 years) and had a normal endocrine evaluation. Plasma FSH, LH, oestradiol, inhibin A, B, pro-αC and total α inhibin were measured by immunoassay prior to and following gonadotrophin stimulation. Immunoactive FSH, LH and oestradiol blood concentrations following pituitary down regulation were similar in the two groups being <2.0, <3.6 IU/l and <82 pmol/l respectively. The units of FSH given (2230 versus 2764 IU; Normegon versus rFSH), duration of treatment (9.1 versus 9.4 days) and number of follicles of ≥14mm on the day of human chorionic gonadotrophin (HCG) administration (17 versus 14) were also similar. Inhibin A or B concentrations rose similarly during Normegon or rFSH administration, peaking at days 9–11. Total α and pro-αC inhibin concentrations were lower (P < 0.05) in the rFSH group during days 10 and 11 of treatment being 18.9 ± 15.9 ng/ml (Normegon) and 4.6 ± 2.8 ng/ml (rFSH) for total α inhibin and 8.5 ± 6.8 ng/ml (Normegon) and 2.8 ± 1.6 ng/ml (rFSH) for pro-αC inhibin on day 10. Overall, higher total α inhibin concentrations were associated with more mature follicles and oocytes, greater fertilization rates and better quality embryos. We conclude that inhibin A and B secretion was similar in both groups and is primarily controlled by FSH, whereas total α inhibin and pro-αC increased preferentially in the Normegon group over the rFSH group, indicating that they are, in part, stimulated by LH. [ABSTRACT FROM PUBLISHER]

Familial polycystic ovarian syndrome (PCOS) has been proposed to be linked to a site near the follistatin gene. We studied the concentrations of circulating follistatin, activin A and inhibin B in well-characterized subjects with PCOS (n = 108) and controls without PCOS (n = 20). Mean (± SEM) concentrations of follistatin were higher (P < 0.05) in PCOS (0.27 ± 0.03 ng/ml) than controls (0.15 ± 0.02 ng/ml) and activin A were lower (P < 0.05) in PCOS (0.20 ± 0.01ng/ml) than controls (0.24 ± 0.02 ng/ml). Inhibin B concentrations were not different between the two groups: PCOS (0.06 ± 0.01ng/ml), and controls (0.06 ± 0.01ng/ml). It is proposed that higher concentrations of follistatin with lower concentrations of activin A may relate to follicular development not proceeding beyond 8–10 mm and may be partly responsible for the lack of pre-ovular follicle development in PCOS. [ABSTRACT FROM PUBLISHER]

Inhibins are regulators of paracrine and endocrine function during pregnancy, but their intrauterine sites of secretion are not well established. In amniotic fluid, inhibin A-, inhibin B- and inhibin pro-αC-containing isoforms were present in high concentrations, whereas in maternal serum, inhibin A and pro-αC forms were present in high amounts, with low concentrations of inhibin B. In fetal cord serum, inhibin pro-αC was present in all samples, inhibin B was detectable in male but not female fetuses, with no detectable inhibin A in either sex. From cultured explants, both inhibin A and B were secreted by chorion laeve, whereas only inhibin A was secreted by placenta, with both tissues secreting inhibin pro-αC. Only low concentrations of both dimeric inhibins and pro-αC forms were secreted by decidua parietalis and amnion. The dual perfused placental cotyledon secreted both inhibin A and pro-αC into maternal perfusate, but only inhibin pro-αC into the fetal circulation and less than to the maternal side. We conclude that trophoblast is the predominant source of dimeric inhibins, but with markedly different secretion depending on its intrauterine location. There was a significant decrease in inhibin A and pro-αC in amniotic fluid collected at term active labour compared to elective Caesarean section (P < 0.001). This may reflect a local change in inhibin/activin processing at labour, likely in chorion laeve trophoblast cells, which may be important in the paracrine control of the feto-maternal communication required to maintain pregnancy and initiate labour. [ABSTRACT FROM PUBLISHER]

Inhibins are present in maternal serum during pregnancy. However, the presence of inhibins in the compartments surrounding the fetus in early pregnancy is not well defined. Using novel specific enzyme-linked immunosorbent assays we have demonstrated that the bioactive dimeric inhibin forms, inhibin-A and inhibin-B, and the immunoreactive inhibin forms containing pro- and αC sequences are present in different amounts in the extra-embryonic coelomic and amniotic fluids and maternal serum between 8–11 weeks gestation. Of the bioactive dimeric inhibins, both inhibin-A (mean ± SEM 236.0 ± 24.8 pg/ml) and inhibin-B (62.0 ± 8.6 pg/ml) are present in extra-embryonic coelom, whereas no dimeric inhibin is present in the amniotic fluid and only inhibin-A (360.2 ± 32.9 pg/ml) is present in maternal serum. Furthermore, pro-αC-related immuno-reactivity is present at high concentrations in the extra-embryonic coelom (591.7 ± 60.5 pg/ml), amniotic fluid (452.4 ± 76.8 pg/ml) and maternal serum (539.4 ± 39.5 pg/ml). These findings would indicate that at this stage of gestation inhibin-A, inhibin-B and immunoreactive pro-αC-containing inhibin production are likely to arise from different sources including the fetus, placenta and fetal membranes and maternal sources including the ovary. Inhibins may be important regulators of fetal and placental development and involved in the establishment of pregnancy. [ABSTRACT FROM PUBLISHER]

Inhibin (and its alpha-subunit) may be of particular value as a marker for follicular development in in-vitro fertilization (IVF) in comparison with the classic follicle stimulating hormone (FSH)-dependent marker oestradiol in patients following pituitary desensitization and treatment with recombinant FSH (rFSH). This preparation lacks luteinizing hormone (LH), which is essential for thecal cell androgen secretion and thus oestradiol production. Our study has assessed oestradiol and immunoreactive inhibin-like secretion following ovarian stimulation with rFSH or a purified urinary FSH preparation (Metrodin) (uFSH). A randomized, assessor-blind study was initiated using patients receiving a single treatment cycle of IVF (using fresh embryos) following pituitary desensitization with intranasal buserelin (500 microg daily) and the i.m. injection of either rFSH (n = 38) or uFSH (n = 17). Ovarian ultrasound examinations were performed and bloods (10 ml) collected prior to FSH treatment and every 1-2 days until ovulation induction with human chorionic gonadotrophin. LH and FSH concentrations were measured by an immunoradiometric assay, and inhibin-like immunoreactivity by a radioimmunoassay and an enzyme-linked immunosorbent assay, both with alpha-subunit specificity. Oestradiol concentration was measured with a coated tube radioimmunoassay. Following desensitization, basal LH, FSH and oestradiol concentrations were measured, as was that of immunoreactive inhibin. Following treatment with either rFSH or uFSH, LH concentrations remained low while FSH concentrations rose to a plateau of 5.6-6.7 IU/l in both groups. In contrast, the concentration of oestradiol was higher (P < 0.05) with rFSH than with uFSH in the last four days of treatment, a pattern that was repeated for inhibin-like immunoreactivity. The change in oestradiol and inhibin concentrations during treatment was approximately 2-fold higher with rFSH. The total number of follicles obtained with rFSH was similar to that with uFSH. However, the number of follicles with a diameter of >/= 15 mm was higher the rFSH group, and there was a concomitant increase in the number of oocytes recovered. Oestradiol concentration and inhibin-like immunoreactivity (determined by either method) were associated with total follicle number and number of follicles >/= 15 mm in diameter, as well as with each other (P < 0.001). When ovarian hormone output was normalized per follicle produced, oestradiol output was higher for rFSH than for uFSH P = 0.04). Inhibin output was clearly higher using rFSH than uFSH. There were seven pregnancies (one miscarriage) with rFSH and two with uFSH. Despite similar concentrations od FSH in patients, rFSH (Puregon) appears to be more potent in vitro in terms of follicular number, ovarian hormone secretion (both concentration and output/follicle) and oocyte recovery. In both groups, LH concentrations of approximately 1.3 IU/l were sufficient to support oestradiol secretion similar to that normally found in IVF programmes using human menopausal gonadotrophin preparations containing large amounts of LH. Despite known problems of specificity with the assays od inhibin, its measurement was of similar value to oestradiol as a marker of follicular development. [ABSTRACT FROM AUTHOR]

This study was designed to assess the involvement of follicle stimulating hormone (FSH)—granulosa and luteinizing hormone (LH)—theca axes in the antifolliculotrophic effect of mifepristone. Plasma gonadotrophins, including plasma LH bioactivity and pulsatility, oestradiol, testosterone and inhibin concentrations, and follicular growth were monitored in volunteer women treated with placebo or mifepristone in two consecutive cycles. Mifepristone was given either as a single dose of 5 mg ( = 7) when the leading follicle had reached a diameter between 12 and 14 mm, or as a multiple dose of 5 mg/day for 3 days, beginning when the leading follicle had reached a diameter between 14 and 16 mm ( = 5) or between 6 and 11 mm ( = 5). Following the single dose of mifepristone, follicular growth and the accompanying increase in plasma oestradiol were arrested at 12 and 36 h respectively without changes in gonadotrophin or testosterone serum concentrations. The 3 day regimen arrested follicular growth and oestradiol rise and decreased plasma inhibin concentrations when follicles were larger than 12 mm at the onset of treatment. These results indicate that the antifolliculotrophic action of mifepristone is associated with a selective compromise of the FSH—granulosa axis of dominant follicles that have passed a critical stage of growth. [ABSTRACT FROM PUBLISHER]

Static measurements of immunoreactive inhibin have proved to be of little relevance in the diagnosis of testicular disorders. To explore whether a dynamic evaluation of inhibin secretion might yield a more useful parameter of testicular function we compared the responses of inhibin with steroids to i.v. injections of pure follicle-stimulating hormone (FSH; 300 IU) or human chorionic gonadotrophin (HCG; 1500 IU) and oral administration of the antioestrogen Tamoxifen (20 mg/day for 7 days) in four normal fertile men. Blood was aspirated between 1 and 72 h after the injections and daily during Tamoxifen intake. Four controls were injected with physiological saline solution. An additional four men were injected with pure FSH, and blood was taken after 24, 48 and 72 h. Injection of FSH was accompanied by nycthemeral variations of testosterone comparable with those observed in the controls. The concentration of inhibin showed similar nycthemeral variations but a significant increase was observed in all eight cases at 12 noon on days 2 and 3 after FSH injection. HCG injection resulted in the expected biphasic response of testosterone. Inhibin displayed a pronounced increase 18 h after injection but the delayed response after 48 and 72 h was not observed. Tamoxifen intake increased testosterone but not inhibin, and caused a moderate and temporary increase of luteinizing hormone and FSH. It was concluded that primary stimulation both of Leydig cells by HCG and Sertoli cells by FSH increase circulating inhibin. Comparison with the testosterone response suggests that the inhibin peak 18 h after HCG administration may reflect Leydig cell function, and that the delayed response 48 and 72 h after FSH administration can be used as a parameter of Sertoli cell function. [ABSTRACT FROM PUBLISHER]

Seven women suffering from hypogonadism due to previous hypophysectomy, isolated gonadotrophin deficiency, or Kallman's syndrome [median age 39 years (range 24–45)] volunteered to participate in a study to assess ovarian response following multiple-dose administration of recombinant human follicle-stimulating hormone (rhFSH; Org 32489). Baseline serum FSH and luteinizing hormone (LH) concentrations were 0.25 (<0.05–1.15) IU/l and 0.06 (<0.05–0.37) IU/l, respectively. Subjects received daily i.m. injections of rhFSH for 3 weeks (week 1: 75 IU/day, week 2: 150 IU/day, week 3: 225 IU/day). Blood sampling and sonographic investigations were performed on alternate days. Steady-state FSH concentrations were reached ∼3–5 days after alterations of the doses administered. Maximum FSH concentrations were between 7.1 and 11.8 IU/l, whereas serum LH concentrations remained unchanged. Due to absent follicle development and lack of a rise in immunoreactive inhibin (INH) (response failure possibly due to early ovarian failure or resistant ovary syndrome) in two subjects, analysis of ovarian response was restricted to five volunteers. Serum androstenedione levels showed no significant changes during rhFSH administration. Although serum immunoreactive INH concentrations reached normal late follicular values [659 (388–993) IU/l], serum oestradiol revealed only a minor increase [77 (18–210) pmol/I]. Moreover, growth of (multiple) ovarian follicles was observed up to pre-ovulatory sizes (>15 mm) in these patients. It may be concluded from the present study that (i) rhFSH exhibits no intrinsic LH activity; (ii) rhFSH stimulation in hypogondotrophic women resulted in an immunoreactive INH rise which was similar to that in normal women, whereas in contrast only a minor increase in oestradiol concentrations was observed (suggesting normal granulosa cell function and low availability of androgens as a substrate for aromatization); (iii) despite the minimal oestrogen increase, ovarian follicles developed normally to the pre-ovulatory stage. [ABSTRACT FROM PUBLISHER]

Concentrations of inhibin, oestradiol and progesterone were determined in pre-ovulatory follicular fluid from 16 women undergoing in-vitro fertilization and embryo transfer treatment. A prospective randomized design was used such that ovulation was induced in eight women with human chorionic gonadotrophin (HCG) (9000 IU), and in eight women with an endogenous surge of luteinizing hormone (LH) and follicle stimulating hormone (FSH) caused by a single injection of gonadotrophin-releasing hormone agonist (GnRHa). Inhibin was measured by an enzyme-linked immunosorbent assay, and oestradiol and progesterone were measured by radioimmunoassay. Concentrations of inhibin and progesterone are significantly higher in follicular fluids collected after ovulation induction with HCG compared with ovulation induction with GnRHa ( < 0.001, < 0.02, respectively). Concentrations of oestradiol were similar in the two groups. This study shows that the method by which ovulation is triggered significantly affects the micro-environment of the oocyte just prior to ovulation. The results indicate that HCG causes a prolonged luteotrophic effect well before ovulation, compared to an endogenous surge of gonadotrophins caused by GnRHa, and suggest that follicular maturation with an endogenous surge of gonadotrophins may be closer to the natural cycle than those cycles in which HCG is administered for ovulation induction. In addition, this study shows that the concentrations of inhibin and progesterone in follicular fluid may be valuable parameters in assessing the midcycle LH surge requirements for induction of ovulation. [ABSTRACT FROM PUBLISHER]

This paper reviews our current knowledge of the role of testicular inhibin in the regulation of follicle stimulating hormone (FSH) secretion in the rhesus monkey. Species differences between monkey and rat are described, and evidence for and against the hypothesis that control of FSH secretion in the human male is similar to that for the monkey is presented. [ABSTRACT FROM PUBLISHER]

We have developed three specific enzyme-linked immunosorbent assay (ELISA) formats which quantitate inhibin A in conditioned media and serum. The assays are sensitive in a range 0.078–5.0 ng/ml and have been characterized in terms of cross-reactivity to inhibin related proteins. The CK:CK assay format recognizes inhibin A, inhibin B and inhibin-related molecules, while the 9A9:CK assay format recognizes inhibin A and inhibin A precursors, but not free α-subunit. The 11B5:CK assay appears to recognize only mature 32 kDa inhibin A. Additionally, we have developed separate, specific ELISA formats which quantitate activin A and activin B. The assays have a range of 0.2–50 ng/ml and 0.4–50 ng/ml for activin A and recombinant activin B, respectively. These assays are presently being used to examine the concentration of inhibin A, activin A and activin B in clinical serum samples. [ABSTRACT FROM PUBLISHER]

The pituitary–ovarian axis describes a regulatory system in which pituitary gonadotrophins stimulate ovarian folliculogenesis and the production of both steroid and protein hormones, which in turn exercise feedback control on the pituitary and hypothalamus. The availability of a radioimmunoassay for serum inhibin has allowed exploration of inhibin's role in the regulation of follicle stimulating hormone (FSH). This gonadotrophin stimulates ovarian inhibin secretion within the physiological dose range, both after exogenous administration and during endogenous rises, as are seen during puberty and the mid-cycle FSH surge. No direct evidence of FSH suppression by inhibin administered to human subjects has been obtained. During periods of endogenously raised inhibin levels, however, FSH is suppressed, as seen during the luteal phase of the menstrual cycle (luteinizing hormone drives inhibin production at that time), during pregnancy and in patients with inhibin-secreting granulosa cell tumours of the ovary. In contrast, decreased inhibin levels in the presence of intact hypothalamo-pituitary function result in increased FSH concentrations—as in early childhood, during the luteal–follicular transition and during reproductive ageing. After the menopause inhibin levels are normally undetectable, with FSH being markedly elevated. These observations are compatible with a role for endogenous inhibin in the regulation of FSH, though the contribution of oestradiol is hi most instances impossible to dissect out separately. [ABSTRACT FROM PUBLISHER]

Hypersecretion of luteinizing hormone (LH) is a significant cause of infertility and miscarriage in women with the polycystic ovary syndrome. Many theories have been suggested for the aetiology of pituitary oversecretion of LH. These include increased pulsatility of gonadotrophin releasing hormone (GnRH) hypothalamic dysfunction, altered pituitary sensitivity to GnRH, hyperinsulinaemic stimulation of the pituitary gland and perturbed ovarian–pituitary feedback of steroid hormones. None of these hypotheses fully explain the phenomenon of LH hypersecretion and there has been much debate in the literature on this subject. This paper reviews some of the important clinical studies that have examined the evolving story of hypersecretion of LH and presents in-vivo and in-vitro evidence that suggests that disordered ovarian–pituitary feedback is central to the problem, possibly through a perturbed secretion of nonsteroidal ovarian hormones. [ABSTRACT FROM PUBLISHER]

Serum inhibin concentrations of 64 cycles of in-vitro fertilization-embryo transfer (IVF-ET) or gamete intra-Fallopian transfer (GIFT) have been analysed retrospectively. No significant difference was observed in serum inhibin levels of cycles stimulated with buserelin and human menopausal gonadotrophin (HMG) or HMG alone. During the late follicular phase, serum inhibin was higher in cycles resulting in pregnancy than in cycles without a pregnancy (peak values on day +1: 8.3 versus 6.4 IU/ml, respectively). The same difference was found between stimulation cycles resulting in a viable or a non-viable pregnancy (peak values on day +1: 8.3 versus 7.5 IU/ml). However, these differences were not significant. During the early luteal phase, serum inhibin values were similar in these groups of patients. Our results indicate that the use of the gonadotrophin-releasing hormone (GnRH) analogue buserelin, in combination with HMG, for ovarian stimulation does not affect inhibin production by granulosa cells . The late follicular and early luteal concentrations of serum inhibin have to be considered unsuitable as predictors in IVF/GIFT cycles with respect to pregnancy and pregnancy outcome. [ABSTRACT FROM PUBLISHER]

Biosynthetic human growth hormone added to an ovarian stimulation regime of human menopausal gonadotrophin (HMG) for IVF treatment improves the response of women who were previously resistant. This study investigated the efficacy of growth hormone (GH)/buserelin/HMG treatment in women with a previous normal response to buserelin/HMG stimulation. Ten patients (28–36 years, mean 32.5 years) were treated with GH (6 IU/day) plus buserelin/HMG. A control group of 10 women (28–37 years mean 31.0 years) received buserelin/HMG alone. All were given buserelin 500 μg and 2 ampoules (150 IU) HMG daily once pituitary suppression had been confirmed. There was no improvement in the GH group as assessed by follicular growth rate or number, oocyte number per woman and pregnancy rate. There was no effect of GH upon the serum oestradiol level and the follicular fluid levels of oestradiol, GH and inhibin. Serum IGF-1 increased significantly during GH administration, returning to pre-treatment levels 2 days after the last dose of GH. Follicular IGF-1 was much higher in the GH-treated group than the controls. Significant correlations were found in the GH-treated group between follicular fluid GH and follicular fluid oestradiol concentrations and between follicular GH and follicular size. Follicular IGF-1 was correlated with the serum IGF-1 concentration on day 8 of the GH/HMG treatment. In conclusion GH/buserelin/HMG treatment in women with a previous normal response to buserelin/HMG stimulation increased their- serum and follicular IGF-1 concentrations. However, it does not improve the clinical ovarian response or the follicular secretion of oestradiol or inhibin. [ABSTRACT FROM PUBLISHER]

Concentrations of inhibin, total and free oestradiol and progesterone were determined in preovulatory follicular fluid from 15 women undergoing in-vitro fertilization and embryo transfer treatment. The women underwent ovarian stimulation using clomiphene citrate and human menopausal gonadotrophin (HMG) (69 follicular fluid samples) in one cycle, and gonadotrophin-releasing hormone agonist (GnRHa) and HMG stimulation in the next treatment cycle (64 follicular fluid samples). The women thereby served as their own control. Inhibin, total oestradiol and progesterone were measured by radioimmunoassay. Concentrations of free steroid were calculated after quantitation of the steroid binding proteins, i.e. sex-hormone binding globulin (SHBG), cortisol binding protein (CBP) and albumin. Levels of inhibin and free and total progesterone were significantly higher in follicular fluids collected after stimulation with the GnRHa compared to the clomiphene regime ( < 0.05, < 0.001, < 0.001, respectively). In contrast, levels of total and free oestradiol in follicular fluid were significantly lower after stimulation with GnRHa than after clomiphene stimulation ( < 0.001). These results indicate that the follicles have achieved a more optimal maturation during the GnRHa regime than during the clomiphene regime. It is suggested that the concentration of free biologically active steroids in follicular fluid, released into the peritoneal cavity during ovulation, may be physiologically important in stimulating the oviduct and the uterus in connection with ovulation, pre-embryo development and implantation. [ABSTRACT FROM PUBLISHER]