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The Yoruba are an important ethnic group mainly occupying Southwestern Nigeria. Mainly for genetic reasons, this very large tribe happens to present the highest dizygotic twinning rate in the world (4.4 % of all maternities). The high perinatal mortality rate associated with such pregnancies has contributed to the integration of a special twin belief system within the African traditional religion of this tribe. The latter is based on the concept of a supreme deity called Olodumare or Olorun, assisted by a series of secondary gods (Orisha) while Yoruba religion also involves immortality and reincarnation of the soul based on the animistic cult of ancestors. Twins are therefore given special names and believed to detain special preternatural powers. In keeping with their refined artistic tradition, the Yoruba have produced numerous wooden statuettes called Ibejis that represent the souls of deceased newborn twins and are involved in elaborate rituals. Among Yoruba traditional beliefs and lore some twin-related themes are represented which are also found in other parts of the world. Basic features of the original Yoruba beliefs have found their way into the religious traditions of descendants of African slaves imported in the West Indies and in South America.

The data of the population-based, prospective survey of multiple births in East Flanders, Belgium, show that a greater proportion of monozygotic twins is observed with clomiphene citrate as sole treatment compared with other ovulatory drugs. Among iatrogenic monozygotic twins, the ratio of monochorionic versus dichorionic pairs is higher compared with spontaneous twins.

The aim of this work was to evaluate the relationship between follicular size at the time of oocyte retrieval, and the subsequent oocyte competence to be fertilized and to develop in vitro. All the obtained oocytes were classified according to the corresponding volume of aspirated follicular fluid. Aspirated volume of follicular fluid2 ml corresponded to a follicular diameter16 mm and constituted the small size group. Volume of follicular fluid from 2 to 6 ml corresponded to a diameter from 16 to 23 mm and constituted the medium size group. The large size group contained follicles with diameter23 mm and corresponded to an aspirated volume of follicular fluid of6 ml. A progressive and significant increase in the rates of oocytes with a first polar body was observed from the small size group to the other groups and from the medium to the large size group: 75.3, 85.9 and 95.3% respectively. After classical in-vitro fertilization (IVF), significantly better rates of fertilization and development were obtained in the medium size group compared to the two other groups. Moreover, a positive relationship was observed between follicular diameter and rates of embryos scored as 'good' when oocytes were fertilized by intracytoplasmic sperm injection (ICSI). These results demonstrated that follicular size is positively related to the oocyte ability to be fertilized and to develop. Although oocytes from small follicles gave lower percentages of development probably due to partial oocyte incompetence, they allowed an increase in the total number of embryos scored as 'good'.

The aim of this study was to determine whether the presence of a hydrosalpinx influences in-vitro fertilization (IVF) prognosis. Comparisons were made between 69 IVF cycles in 37 patients carrying hydrosalpinges (hydrosalpinx group) and 67 IVF cycles in 41 patients without tubes or surgically sterilized (control group). Twenty-two patients carrying hydrosalpinges underwent salpingectomy or salpingoplasty (operated group); they then underwent 42 IVF trials which were compared with the two former groups. In the hydrosalpinx group, pregnancy rates by oocyte retrieval were 10.1% for clinical and ongoing pregnancies. In the control group, the corresponding pregnancy rates were 23.0 and 21.3% respectively. The implantation rate per embryo was 4.2% for clinical and ongoing pregnancies in the hydrosalpinx group and 11.0 and 10.4% respectively in the control group. The operated group had pregnancy rates of 38.1% for clinical pregnancies and 31.0% for ongoing pregnancies, with implantation rates of 17.4 (clinical) and 14.8% (ongoing) respectively. Pregnancy and implantation rates were statistically lower in the hydrosalpinx group as compared with controls and with the operated group. The differences between control and operated groups were not significant. In conclusion, the presence of a hydrosalpinx is thus associated with poor prognosis in IVF treatment. Surgical correction of such lesions appears to restore high success rates.

A pathologic investigation was conducted on 100 placentas collected from pregnancies resulting from in vitro fertilization (IVF) and intrauterine embryo transfer (ET), including 70 singleton pregnancies, 20 twin pregnancies, and 10 multiple pregnancies complicated by the vanishing twin (VT) phenomenon (n = 5) or artificially reduced (n = 5). These results were compared with those for 70 spontaneous spontaneous singleton and 20 spontaneous twin pregnancies. In cases of singleton pregnancies, the incidence of abnormal placental shapes was significantly different (P < .025) in the IVF group compared to controls. A significant (P < .005) difference was also observed between these groups in terms of umbilical cord insertion. The mean distance between the cord insertion and the closest placental margin was significantly (P < .001) shorter among IVF singleton pregnancies (3.19 +/- 1.83 versus 4.62 +/- 2.23 cm). In cases of twin pregnancy, no difference was found between IVF and spontaneous pregnancy in the incidence of pregnancy complications and distribution of cord insertion. First-trimester bleeding was the only clinical sign of the disappearance of an embryo in multiple pregnancies complicated by the VT phenomenon and was not observed in multiple pregnancies artificially reduced. The present findings support the hypothesis that marginal cord insertion is secondary to oblique orientation of the blastocyst at the nidation. A larger trial is now required, analyzing the placental features from IVF pregnancies in relation to the etiology of infertility.

The usefulness of opening the zona pellucida by partial zona dissection (PZD) to enhance fertilization of mature mouse oocytes was studied after insemination with three types of semen: normal and diluted semen and semen from long-term-vasectomized males. Zona opening did not by itself induce parthenogenetic cleavage of mature oocytes and did not significantly increase mono- and polyspermic fertilization of oocytes inseminated with normal semen. While a fertilization rate of 62% was obtained among intact oocytes, of which 4.5% were polyspermic, a 66.8% fertilization rate was observed among PZD oocytes, 6.3% of which were polyspermic. However, after using diluted semen, only 54 of 193 intact oocytes were fertilized (28%), and PZD improved the fertilization rate to 65.4%. Cleavage rate of nonmanipulated oocytes inseminated with abnormal semen from vasectomized males was dramatically decreased in comparison with those inseminated with normal semen (7.6% vs. 65%). PZD induced a moderate but significant improvement of fertilization performance when using this abnormal semen (19.6%).

The fertilization rates observed in 122 attempts at in-vitro fertilization were examined in relation to sperm characteristics assessed by visual and automated screening. Using linear regression analysis, a significant correlation was found between the fertilization rate and (i) evaluations in fresh semen sperm concentration, percentages of sperm motility, vitality and normal morphology and velocity, (ii) measurements in swim-up preparations of percentages of sperm motility, vitality and morphology, velocity and amplitude of lateral head displacement. No significant correlation was found between the fertilization rate and any of the parameters studied in 24-h-old swim-up suspensions. Analysis by multiple variable stepwise linear regression showed an optimal correlation (R 6 = 0.62) between the observed fertilization rate and theoretical calculation obtained from the following predictive function: fertilization rate = -0.3 + (0.008 x swim-up motility) + (0.004 x normal sperm morphology in fresh semen). Introduction of kinematic characteristics studied by automated screening improved the multiple correlation between the calculated and observed fertilization rate in cases of normal or mildly defective semen. Because of the limited availability of motile spermatozoa, automated analysis could not supersede classical sperm analysis in cases of more severe sperm defects.

Among 599 trials of in-vitro fertilization (IVF) treatment, complicated ovarian hyperstimulation (OHSS) was diagnosed in 14 cases (2.5%) on the basis of heavy abdominal discomfort and echographic findings (ascites, ovarian enlargement with cysts). Among eight hospitalized patients, four presented with a haemoconcentration and/or electrolytic disturbances. OHSS cases were compared with two control groups for a series of criteria: age, aetiology of infertility, total dose of human menopausal gonadotrophin (HMG), day of oocyte collection, oestradiol (E2) peak level, rate of E2 increase, number of oocytes, number of embryos transferred and embryonic vitality scores. Comparison with a random group of normal IVF trials showed a significant difference for the following parameters: E2 peak level and rate of increase, E2/dose of HMG, E2/day of egg collection and number of oocytes. When OHSS cases were compared to another control group consisting only of high E2 responders (peak E2 greater than 2700 pg/ml), no significant difference was found for any of the above-mentioned criteria. In view of this lack of predictive power of individual criteria, stepwise discriminant analysis was applied, showing that this method might provide a predictive mathematical function for evaluating the risk of OHSS before human chorionic gonadotrophin (HCG) administration. Such a formula, however, should be validated by a multicentric study in which a greater number of OHSS cases would be tested.

The multicentric study regroups 128 cases of the ovarian hyperstimulation syndrome (OHSS) in in-vitro fertilization (IVF) and 256 selected controls. Values of serum oestradiol obtained from different laboratories were found to be normally distributed after logarithmic transformation. Comparative study of clinical and biological characteristics indicates that among OHSS patients (i) mean age was lower; (ii) tubal indications for IVF were less frequent; (iii) polycystic ovary-like conditions (i.e. hyperandrogenism, anovulation, luteinizing hormone/follicle stimulating hormone ratio > 2) were more frequent. OHSS patients displayed ovarian hypersensitivity reflected by higher oestradiol peak concentrations in response to lower dosage of human menopausal gonadotrophin and by a steeper slope of oestradiol increment during stimulation. In these patients, the collection of greater numbers of fertilizable oocytes allowed replacement of more embryos with a good vitality score. Ongoing pregnancy rate was found to be higher among the OHSS patients. The following complications were recorded among OHSS cases: abdominal fluid at echographic examination or clinical ascites (86.7 and 71.1%, respectively); pleural and pericardial effusion (21 and 3%, respectively); haemoconcentration (71.1%); electrolytic disorders (6.2%). Although significantly different between groups, clinical and biological parameters under study showed considerable overlap of their distributions in control and OHSS cases. Therefore, these data must be submitted to discriminant analysis in order to derive a formula predictive of the risk of OHSS.

Mature mouse oocytes were exposed prior to in vitro fertilization to visible light during 1, 2, or 4 hr at an intensity of 4,000 lux. Compared to controls cultured under identical conditions but protected from light, exposed eggs did not show any significant modification of cleavage speed and rate. After transfer of blastocysts obtained in vitro in uteri of pseudopregnant females, the implantation rate and the proportion of normal fetuses were not found to be different in relation to preliminary light exposure of oocytes fertilized and cultured in vitro.

The influence of partial zona dissection (PZD) on the fertilization rate was studied in 34 couples with a history of fertilization failure and/or severe sperm deficiency. Overall, PZD improved the rate of monospermic fertilization compared to controls (41/254 versus 6/111: P less than 0.001) and fertilization was achieved in 50% of cases. However, the results differed according to the seminal characteristics. In 10 couples with at least two in-vitro fertilization (IVF) trials entailing total fertilization failure and with semen defined as normal, PZD did not significantly improve the monospermic fertilization rate (6/44 in the PZD group versus 2/39 among controls). A benefit related to PZD was evident in 33 attempts with severe sperm deficiency. In this group, only four of 72 unmanipulated control oocytes were fertilized but the monospermic fertilization rate was 14.6% for PZD oocytes. The rates of polyspermy were 40% and 14.6% in the groups with normal and abnormal semen parameters respectively. Of 33 trials with defective spermatozoa, 20 reached the stage of embryo transfer and three pregnancies were obtained, of which one aborted at 9 weeks.

A comparison has been established retrospectively between clomiphene citrate-human menopausal gonadotropin (CC-hMG) and buserelin acetate-hMG treatments in in vitro fertilization trials performed over a 3-year period. The analysis of 466 CC-hMG and 319 buserelin acetate-hMG trials shows that buserelin acetate-hMG stimulation generates a greater ovarian response resulting in higher numbers of oocytes being retrieved (6.2 + 3.8 versus 9.3 + 5.2) and fertilized (2.8 + 2.7 versus 4.3 + 3.8). More embryos are thus obtained, allowing a wider choice for intrauterine replacement and cryopreservation. Mean embryonic vitality scores do not differ (4.33 + 1.51 versus 4.44 + 1.54), implying that the embryonic quality remains similar in both treatments. A premature demise of the corpus luteum occurs in a large proportion of buserelin acetate-hMG cycles. However, when suppletive progesterone treatment is given, there is a trend toward a better implantation rate per embryo, and a significantly higher ongoing pregnancy rate is observed in relation to buserelin acetate-hMG treatment (20%) as compared with CC-hMG cycles (14%).

Among 297 couples who underwent 587 oocyte collection procedures, 95 (16%) total fertilization failures (FF) were observed. This frequency is similar in couples with either normal or only mildly deficient spermatozoa (16.2 and 13.7% respectively) but is almost doubled in cases of moderately and severely defective sperm (26.5%). However, this latter group accounts for only 19% of FF events. The fertilization rate per oocyte (FR) follows an inverse trend. FR was correlated with the final (i.e. after swim-up) sperm count and with initial and final motility of the sperm sample. If the final count and motility were less than 2 x 10(6)/ml and 40% respectively, the FF frequency in the group with partner's spermatozoa was significantly higher and FR significantly lower. FR was inversely correlated with the number of oocytes recovered but FF was found significantly more frequently only when fewer than three eggs were retrieved. No correlation was found between FF and either female causes of infertility, age or dosage of stimulation treatment. However, in the group with donor spermatozoa the FR was significantly lower amongst tubal, endocrinopathic and endometriotic patients (67.6, 67.2 and 56.6 respectively versus 79.7% in harvests from idiopathic cases). FR was decreased and FF increased when ovulation induction resulted from a spontaneous LH peak supplemented with human chorionic gonadotropin (HCG), as compared to induction by HCG alone. In the group using normal or mildly defective spermatozoa, if FF occurs at the first attempt, the frequency of recurrence in further trials is high (29%) and the probability of pregnancy after completed trials is low (12.5%).(ABSTRACT TRUNCATED AT 250 WORDS)

Within the same in vitro fertilization (IVF) program, treatment trials leading to single and multiple ongoing gestation were compared. Rates of cesarean delivery, prematurity and perinatal mortality were found much higher among twin and multiple IVF pregnancies. Our work thus attempts at defining characteristics of proneness to multiple gestation in IVF treatment, in order to try and avoid its occurrence. The mean vitality score of embryos replaced is the most reliable criterion for this purpose, enabling one to replace no more than two embryos when the average score is high. Age of the patient and cause of infertility are almost nondiscriminant in this respect. Ovarian stimulation parameters such as total dosage of gonadotropin treatment and level of estrogenic response, as well as numbers of oocytes and embryos obtained, may serve as secondary criteria for assessing the twinning risk.

The effects of varying pH levels on superovulated mouse oocytes before in vitro fertilization, culture, and transfer were investigated. Mouse oocytes acidified for 1 hour with 20% CO2(pH 6.9) exhibited a wide range of alterations. Five hours after insemination, 25% of these eggs showed different degrees of cytolysis and their perivitelline space contained numerous spermatozoa. At 12 hours normal-looking eggs from this group showed a higher proportion of polypronuclear zygotes than the control group (exposed, 51%; controls, 18%). Acidification thus markedly increased the permeability of the zona pellucida and/or interfered with the normal block to polyspermy. Fewer eggs achieved the two-cell stage among groups submitted to acidotic pH levels (6.9 to 6.6). In contrast, alkaline conditions (pH 7.8) did not reduce the proportion of two-cell embryos. However, only eggs maintained at pH 7.5 were capable of producing 80% of blastocysts. In other groups developmental blockage occurred mainly between stages 2 and 4. A significant reduction was found in the proportion of recipient females becoming pregnant after intrauterine transfer of blastocysts originating from CO2- treated oocytes. This difference might be related to the existence of a large polyploid population among experimental eggs.

Systemic administration of various doses of actinomycin D to ovariectomized pregnant rats treated with progesterone (P), was unable to induce implantation of 'delayed' blastocysts in a significant number of animals. However, under the same conditions, topical injection of this drug into the parametrium entailed the occurrence of implantation sites into the homolateral uterine horn in 71% of rats. It is concluded that actinomycin D precipitates implantation by acting directly on uterine cells. Intraparametrial injections of α-amanitin or cycloheximide did not elicit significant rates of implantation.

A semi-quantitative and non-invasive method for scoring embryos obtained after in-vitro fertilization (IVF) has been defined, aiming at selection of embryos before transfer and at prognostic evaluation of IVF trials. Grading of embryos observed on the inverted micrclscope was essentially based on the amount of anucleate fragments expelled during early cteavage and on developmental speed. Embryos endowed with a high score were more often associated with pregnancy and in particular with the occurrence of maple pregnancy. No difference was observed between scores attributed to embryos related to ongoing, aborted or chankal pmgnades. Average embryonic scores corrrsponding to double and triple transfers differed significantly in failures as well as pregnancies. The better quality of embryos replaced in triple transfers was also apparent from the significantly higher implantation rate per embryo observed in this group. From our results, five criteria including clinical data and embryonic scores can be derived for defining a high risk of multiple pregnancy prior to transfer. It might be warranted to replace only two embryos when these conditions are fulfilled. © 1987 IRL Press Limited.

Among 429 patients admitted in our in-vitro fertilization (IVF) programme during the last 3 years, 106 experienced cancellation of one or more treatment cycles. A low oestrogen (E 2) response represented by far the main reason for cancellation (144/184). Significantly lower clinical pregnancy rates were found in the group of patients with low E 2-cancelled cycles (E 2CC) as compared to the rest of the IVF population (13 versus 37%). Further comparison between these groups showed only little or no difference in the mean age of patients, basal FSH levels, number of egg collections, rate of oocytes obtained and fertilized per trial and mean embryonic vitality score. A large majority of E 2CC patients were found to belong to the tubal infertility group (75%) as opposed to a lower proportion of tubal cases among other IVF patients (56%). E 2CC tubal patients showed a lower pregnancy rate than other cases with abandoned cycles and also than other tubal patients (8.9 versus 25 and 35%, respectively). Mean numbers of previous laparotomies, of attempts at oocyte retrieval and of oocytes recovered per trial were similar in tubal patients with or without E 2CC. However, in the E 2CC tubal group mean age and basal FSH levels were somewhat higher, whereas E 2 peak values and fertilization rates were lower, leading to a greater proportion of trials without embryo transfer. Embryonic scores and the E 2/P ratio at day 3 of the luteal phase did not differ signficantly. It may be concluded that cancelling of a cycle because of a low E 2 response in a patient with tubal infertility is indicative of a poor prognosis in further IVF trials.

Luteal phases after in vitro fertilization (IVF) and embryo replacement have been studied in 241 cycles. A positive correlation was observed between the follicular estradiol (E2) peak and the progesterone (P) level on day 3 of the luteal phase, but not correlation was found between the E2-peak value and the luteal-phase duration or midluteal P concentration. When the trials were classified in relation to their outcome (i.e., clinical pregnancies, chemical pregnancies, or failures), the mean P level on day 3 of the luteal phase was significantly higher in clinical pregnancies than in chemical pregnancies and in failures. Mean E2 levels on day 3 were not significantly different among the three groups. Values of the E2/P ratio were significantly higher in chemical pregnancies than in the other groups. No significant differences were observed among the three groups on day 8. When comparing trials ending in failure to those leading to clinical pregnancy for the same patients, pregnancies were obtained in cycles in which early luteal P was higher and the early luteal E2/P ratio was lower than in failures cycles. These data suggest that high P levels and a low E2/P ratio in the early luteal phase might have a favorable influence on the implantation process in human IVF.

A continuous series of 483 twin deliveries was studied. In 30% of cases, intravenous oxytocic treatment was given for labour induction or to accelerate the first stage. In 13% of twin deliveries this treatment was applied only after the first twin's birth. In the group perfused during cervix dilatation, foetal mortality rate was significantly lower than in the nontreated group. In order to understand the reason(s) for this difference, the following factors were studied in relation to oxytocic treatment: parity, obstetrical complications, second stage duration, abnormal presentations, obstetrical maneuvers, and birth weight. Contrasting with mortality data, Apgar scores of first twins were significantly lower in the oxytocin-treated group. In summary, several variables indirectly linked to oxytocic treatment could have favoured or hampered foetal outcome in the treated group. Therefore, it is difficult to ascertain if the use of oxytocics is helpful in twin pregnancy management. In the majority of cases, however, it may at least be considered harmless.

Estradiol growth rate (EGR) during active follicular development was calculated for 89 stimulated in vitro fertilization cycles by exponential curve fit (r = 0.83). Cycles could be divided into four groups with very low, low, moderate, and high EGR values. Cases without oocyte fertilization and/or embryo replacement did not occur in the moderate EGR range, which also corresponded to a significantly better ratio of replaceable embryos versus oocytes recovered. This group was also endowed with a pregnancy rate amounting to 28.5% per laparoscopy and per replacement, i.e., about three times higher than in the three other groups. Very low or high EGR entailed significantly higher percentages of missed oocyte recovery and/or fertilization failure. The frequency of occurrence of a spontaneous luteinizing hormone peak was negatively correlated with EGR. The data indicate that a better outcome of in vitro fertilization may be expected when the estrogen rise starts early in the cycle and adopts a moderate growth rate (0.3 to 0.4).

Endometrial morphology and ultrastructure are studied in 17 spontaneous, 23 stimulated, and 18 artificial cycles in cases of primary ovarian failure. Normal light-microscopic aspect was found, but impaired development of nucleolar channel system and stronger intercellular junction have been observed by electron-microscopic studies in stimulated cycles with relative excess of luteal estrogen. Normal glandular maturation can be obtained in patients with premature menopause, given adequate steroid replacement, but an abnormally dense fibrocytic aspect of the stroma is characteristic of the first treatment cycles.

Between March 1983 and March 1986, 108 pregnancies were obtained at the IVF clinic of St Pierre Hospital in Brussels. There were 29 chemical pregnancies (26.8%), five ectopic pregnancies (4.6%), 15 abortions (14%) and 59 ongoing pregnancies of over 20 weeks (54%). Patients who had experienced a chemical pregnancy at first trial displayed a significantly higher rate of ongoing pregnancy at their second attempt. Among the 15 cases of abortion, a chromosomal anomaly was detected in two cases and suspected in a third. Four of the five ectopic pregnancies occurred in patients with previously documented tubal pathology. The ongoing pregnancies were distributed as 44 singletons, 13 pairs of twins, one set of triplets and one set of quadruplets. The Caesarian section rates were 21 and 40% for single and multiple pregnancies, respectively. The prematurity rate was low for singletons (4.5%) but reached 46.6% in multiple pregnancies. Two minor malformations were observed and five perinatal deaths occurred; among these latter, four cases were twins. It appears that perinatal pathology is substantially higher among IVF pregnancies than in the normal population. It is clear, however, that most of this difference is accounted for by the considerably higher rate of twin pregnancy displayed by the former group.

Our data show that oxytocic perfusion should be liberally given during twin pregnancy labor, since its use is correlated with lower fetal mortality, especially of the second premature twin. This therapy might act, namely, by reducing the number of second-twin abnormal presentations. In our series, the higher mortality rate associated with lengthening of time interval between both births could be attributed to second-twin abnormal presentations. However, mortality rate versus time interval in spontaneous twin deliveries warrants obstetrical management providing second-twin birth within 15 minutes.

Macroscopic characteristics of 100 fetal adnexae from pregnancies obtained by in-vitro fertilization and embryo transfer (IVF-ET) were compared with data for normal pregnancies taken from the literature. Material was obtained from 63 singleton, 15 twin, one triplet and one quadruplet pregnancies. The fetal and placental weights as well as the fetal:placental weight ratio were within the normal range for gestational age. Whilst placental morphology was normal, the insertion of the umbilical cord was frequently abnormal. Marginal (15%) and velamentous (14%) insertions of the umbilical cord were found more frequently than in a general obstetrical population (6% and 1% respectively). Excluding placentae from multiple pregnancies (which are known to have a higher incidence of abnormal cord insertion) the frequency did not decrease and remained significantly higher than in a normal population (P less than 0.01 and P less than 0.001, for marginal and velamentous insertion respectively). Abnormal insertion of the cord is of major clinical importance because of its association with vasa praevia and fetal haemorrhage (Benkiser Syndrome). Since this condition is thought to be caused by disturbed orientation of the blastocyst at implantation it is probably related to the IVF-ET procedure.

Four-hundred-and-ninety-one oocytes were collected from 142 successive patients attending for in-vitro fertilization. The systematic observation of pronuclei between 14 and 18 h after insemination revealed 27 cases of tripronucleate eggs among 391 fertilized eggs (6.9%), which corresponds to rates generally reported in the literature. The following parameters were analysed in relation to the incidence of these eggs: aetiology of infertility, follicular response to hormonal stimulation, type of ovulatory stimulus, sperm count and motility and the incidence of fertilization. Only fertilization rates and concentration of motile spermatozoa in the insemination medium were found to be correlated with tripronucleate eggs, confirming that the condition is predominantly due to polyspermy. Comparisons with data from animals, and measures aimed at preventing polyspermy are suggested.

Groups of ovariectomized rats were taken as controls or given hormonal treatment mimicking the successive steps in the sequence of ovarian secretions leading to implantation. Total endometrium or separated epithelium and stroma were incubated in vitro with [35S]methionine. Dissolved proteins were submitted to two-dimensional polyacrylamide gel electrophoresis (pH range 5-7), followed by autoradiography. Priming with oestradiol (2 days) and subsequent treatment with progesterone (3 days) enhanced the synthesis of 12 and 14 polypeptides, respectively, which are specific for each of these treatments. Progesterone also suppressed the production of 10 oestrogen-dependent proteins both in the epithelium and the stroma. When an oestrogen-progesterone-oestrogen treatment was given, synthesis of all but 4 of the progesterone-induced polypeptides in the epithelium was inhibited while 5 of the proteins abolished by progesterone in this tissue compartment reappeared. These results are compatible with a mechanism of implantation acting at the epithelial level by lifting of intrauterine inhibition and stimulation by embryotrophic substances.

Embryos were recovered on Day 4 of pregnancy from superovulated random-bred OF1 Swiss albino mice. They were classified into four categories based on their stage of development: expanding blastocyst, blastocyst, early blastocyst, and compacted morula. They were then cooled at 2 degrees C/min from -7 to -25 degrees C in a freezing medium containing 1.36 M glycerol and 0.25 M sucrose in phosphate-buffered saline (PBS). At -25 degrees C, they were plunged into LN2 and thawed a few hours later in water at 20 degrees C. After washing in PBS, recovered embryos were cultured for 20 to 24 hr and the number of embryos that had developed normally was recorded. The results showed a clear effect of the stage of development on survival. Survival of expanding blastocysts and blastocysts was very low (1.4 and 21.8%, respectively) compared to that of early blastocysts and compacted morulae (69.4 and 73.5%). The more differentiated stage of the blastocyst (two kinds of cells) and the presence of a blastocoelic cavity may explain the differences observed under our cooling conditions. As a further test of viability, 93 blastocysts that had developed in culture for 20 hr from 153 frozen-thawed early blastocysts and compacted morulae (60.8%) were transferred to 8 recipient mice. Seven became pregnant, yielding 38/82 normal live young (46.3%).

Ovariectomized rats were given hormonal treatment mimicking progestational ovarian secretions. At maximal sensitivity a decidual reaction was induced by scratching the endometrium. After incubation of tissue with [35S]methionine, proteins were extracted from decidualizing and control endometrium and submitted to two-dimensional polyacrylamide gel electrophoresis (pH range 5--7), followed by staining or autoradiography. A total of about 800 different peptides could be distinguished on the gels. By 24 h after the decidual stimulus the most prominent changes were the appearance of 4 new peptides (mol. wt 12 000, 25 000, 42 000 and 56 000) and the disappearance of 5 others (mol. wt 31 000, 35 000, 100 000, 110 000 and 140 000). This new pattern remained grossly unchanged up to 72 h after decidual induction.

In primitive societies twinning raises emotions varying from extreme terror to hope and joy. The first impulse prevailing among the less civilized people seems to be to regard twins as unnatural and monstrous and therefore as portending evil. Accordingly, they must be put to death and the offence repudiated. This negative attitude stems from a series of explanations which can generally be connected with the widespread belief in superfetation and double paternity. In a few cases only, would the custom of sacrificing twins arise from economic necessities. However, in many agricultural primitive tribes, twinning is regarded as a happy event. In this case, the worship of twins entrusts them namely with power over water allowing to confer fertility to the soil and also to women and animals. In the past, the mother of twins was often executed with her offspring or simply banished. In many tribes, she is still compelled to go through elaborate purification in order to forestall the evil omen. If twins are welcomed, their parents are similarly respected as they symbolize the fertility power of the clan. Superstitions and myths pertaining to twinning are universal and often present converging features among cultures without mutual contact. This would point to the twin cult as one of the earliest religious beliefs of mankind.

Thirty-eight single and 10 multiple pregnancies obtained after in-vitro fertilization were compared. In the group of multiple gestations, maternal age was lower and the amounts of ovulatory drugs given were significantly smaller than in relation to single pregnancies. All multiple pregnancies arose from triple embryo transfers and the embryos from this group exhibited significantly higher vitality scores. In both groups, plasma levels of oestradiol and progesterone followed the same pattern until day 8 after oocyte retrieval. Following implantation, the secretion of these hormones increased more rapidly in multiple pregnancies pointing at greater luteal activity in this group. HCG levels became significantly higher in multiple gestation on day 25 after oocyte collection. Echographic examination showed that, compared to normal pregnancy, growth in both groups of IVF conceptuses was initially retarded but caught up with normal evolution at approximately 30 days after egg retrieval. The need for adjusting the number of embryos transferred not only to expected success rates but also to the risk of high rank multiples is emphasized.

Pregnant mice were ovariectomized 3 days after mating and pregnancy was maintained by progesterone treatment. Different regimens of intraperitoneal injections of 3′-deoxyadenosine were applied 3 days after ovariectomy. Repetition of the injections at 3 h intervals induced a significant rate of implantation by delayed blastocysts. Other types of treatment with 3′-deoxyadenosine as well as adenosine injections were found to be ineffective. Paradoxically, 3′-deoxyadenosine treatment had an adverse effect on the overall pregnancy rate found at autopsy.

Regeneration of the uterine luminal epithelium was studied after its mechanical removal in progesterone-primed rats, leaving one control horn intact. Pulse labelling with [3H]TdR during regeneration, showed a rapid peak of labelling index in remaining glands. A differentiated and highly labelled luminal epithelium reappeared at 34 hr, thereafter showing a rapidly declining LI. After initial depletion, the glandular cell population size was restored within 64 hr, whereas luminal epithelium cell numbers became stabilized at about half normal level. Grain counts after prelabelling showed more rapid dilution in gland cells of stripped uterine horns, indicating accelerated cycling of previously dividing cells. Thymidine labelling indices also showed that, after removal of the epithelium, almost all gland cells became rapidly committed to divide. On average, less than two cell cycles were necessary to restore stable glandular and epithelial population sizes. Numbers of labelled cells were also drastically increased in myometrium and serosa of treated horns. This suggests a non-specific mechanism for stimulation of mitotic activity after ablation of epithelium.

Human in vitro fertilization (IVF), as many other medical advances, owes much to work performed on the laboratory mouse. It appears, for instance, that the vast majority of papers which have dealt with the composition and adjustment of media for mammalian IVF and embryo culture have been based on work with mice. Since the genetics of this species has become well-known, mouse eggs are also largely employed in experimental embryology and have become the tool of choice for mammalian transgenic experiments which are being carried out in an increasing number of laboratories [1]. In relation to clinical IVF, mouse embryos are extensively used for routine quality control of culture media and vessels.

After ovarian stimulation with clomiphene citrate combined with human menopausal gonadotropin for in vitro fertilization, the appearance of a spontaneous luteinizing hormone (LH) surge before fulfillment of the minimal criteria of follicular maturity (at least one follicle greater than 19 mm and serum estradiol [E2] greater than 400 pg/ml/follicle greater than 17 mm) is associated with reduced pregnancy rates. In these cases, follicles are smaller and serum E2 values are lower at the time of the LH surge. Oocyte recovery rate is reduced, embryonic anucleate fragments are more frequently observed, and the level of luteal progesterone on day 4 after oocyte retrieval is lower. Hyperandrogenic patients are more prone to display such premature spontaneous LH surge. We concluded that in case of an untimely LH rise, laparoscopy for oocyte retrieval should be cancelled.

One hundred thirty-three couples were classified into four groups according to previous sperm analyses. These couples underwent 237 in vitro fertilization trials that led to 46 clinical pregnancies (19.4%/trial). Clinical pregnancy rate per laparoscopy of the group with male defects was significantly higher than that of the normospermic couples (25 versus 14%, P less than 0.05). The fertilization rate was significantly reduced only if two sperm anomalies were present (P less than 0.05). However, the mean number of embryos transferred did not differ significantly among the four groups, but the proportion of trials without transfer was increased with regard to the severity of sperm defect. Implantation rate per embryo in cases of triple transfer was significantly higher in the group with sperm anomalies as compared with the normospermic cases (18 versus 10%, P less than 0.02). Correction of the male problem through IVF treatment allows higher female fertility to be disclosed in these cases.

Like cyclic AMP or dibutyryl cyclic AMP, intrauterine administration of AMP (non-cyclic) induced implantation in ovariectomized, progesterone-treated mice.

The levels of laminin PI fragment, a marker of basement membrane, and of the aminoterminal sequence of type III procollagen, a marker of interstitial connective tissue, were measured in human preovulatory follicular fluids. The concentrations of these peptides correlated with progesterone levels but not with those of estradiol or testosterone. Immunocytochemical studies confirmed the remodeling of the perifollicular basement membrane and interstitial matrix during oocyte maturation. The studies suggest that monitoring of the ovarian connective tissue macromolecules could be useful for estimating follicular maturation.

SUMMARY The duration of the phase of DNA synthesis (S-phase) and turnover times were measured by autoradiography in the vaginal and endo-uterine epithelium of spayed mice at different times after a single oestradiol injection. With three doses of oestradiol (0·3, 1·2 and 10·0 μg), changes of turnover time followed similar patterns in uterine epithelium, but maximal activation and subsequent levelling off of proliferation rates were reached sooner with higher doses. In the vagina, no significant dose-dependence was apparent with the same doses of oestradiol; maximal activation of cell proliferation was observed in every case 12 h after hormone injection. Transient shortening of S-phase was observed in both tissues under oestrogen stimulation. The morphological changes in uterine epithelium appeared to be independent of mitotic stimulation. For vaginal epithelium, the results may be interpreted to indicate that oestrogen-induced keratinization starts by a differentiating action on pre-existing G1 cells.

1. 1. The athrocytic phenomenon has been used to determine the general hormonal properties and local conditions governing the implantation of the egg in the uterine horn of the rat. 2. 2. Athrocytosis has been found to be under control of the corpus luteum of pseudogestation or gestation. 3. 3. In the uterine horn, athrocytosis may be obtained by simple trauma, provoking liberation of histamine. 4. 4. The evident correlation between this occurrence and nidation has been considered.

Journal Article, info:eu-repo/semantics/published

We have compared breech twins and breech single births in a population recorded between 1974 and 1978 in 10 Belgian maternity centers. In 190 twin pregnancies, 38 first and 65 second twins were delivered in breech presentation. These twins were compared to 853 singleton breeches, of which 95 delivered by cesarean section were excluded. Data were stratified according to birthweight. No significant difference between twins and singletons was found in terms of perinatal mortality rates. However, Apgar scores below 7 at 5 minutes were significantly less numerous among first twins than among singletons. Therefore, first twins in breech presentation might be at lower risk of fetal distress. This difference should be taken into account in the management of first twins presenting by the breech.

THE effects of ovarian hormones on the cell cycle of target tissues have been extensively studied. It has been shown that high doses of oestrogens of exogenous origin can alter the duration of DNA synthesis (S phase) in target tissues when administered alone1,2 or in association with progesterone3.

Crude RNA preparations from uteri of oestradiol-treated rats induced the implantation of delayed blastocysts when injected into the parametrium of ovariectomized pregnant rats. Treatment of donor animals with labelled oestradiol showed that this effect could not be due to contamination of the RNA extracts by oestradiol. RNase digestion of these extracts suppressed their capacity to induce implantation. Purified poly (A)-rich RNA from oestrogen-treated uteri failed to elicit implantation although it was capable of increasing epithelial height when repeatedly injected into uterine horns of ovariectomized rats. These results suggest that uterine RNA synthesis might somehow mediate the effects of oestrogen in causing implantation and that RNAs other than messenger RNA might be involved.