Search

Not before the introduction of the Nomarski differential interference contrast optics (DIC), we became aware of the presence of so-called vacuoles on the surface of the sperm head. Before the implementation of motile-sperm organelle-morphology examination (MSOME), no manuscript at all mentioned that spermatozoa free of vacuole-like structures should be selected for injection.

To determine the best day for the selection and transfer of a single embryo, a prospective, randomized study was undertaken that compared the ongoing pregnancy rate (PR) after single embryo transfer (SET) on day 3 with that after single blastocyst transfer (SBT) on day 5. Our results show an overall significantly higher PR after SBT (32.8%) compared with SET (23.2%), and a PR of 40.8% after SBT versus 25.6% after excellent-quality embryos became available.

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.

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)

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.

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.

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.

The survival after transfer of frozen-thawed mouse blastocysts obtained from culture of in-vitro fertilized oocytes or 1- and 2-cell ova was compared. About 10% of transferred embryos developed to term in each group and there was no difference between embryos fertilized in vitro or in vivo. In addition to embryonic loss due to transfer, in-vitro cultivation and freezing reduced the proportion of fetuses considered viable at Day 15 of pregnancy (29.8 versus 50.7% and 26.3 versus 50.7% respectively). When used together these procedures had an additive effect on fetal wastage (18.4 versus 50.7%). In-vitro culture also entailed a significant increase of resorbing implantation sites (10.2 versus 4.3%). The re-expansion rate after freezing and thawing of blastocysts grown in vitro was paradoxically greater than that of blastocysts grown in vivo (85.8 versus 54.6%).

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.

Forty-nine placentae from HIV-seropositive mothers were collected in various hospitals in France and Belgium. Twenty [corrected] placentae with seven fetuses from interrupted pregnancies and 29 [corrected] placentae from spontaneous deliveries, including two stillborns and a set of twins, were studied morphologically. No significant abnormalities were observed in the aborted material. The placentae corresponding to deliveries presented no significant gross abnormalities but the ratio of fetal to placental weight was significantly decreased in the study group compared with the control group (6.13 versus 7.41; P less than 0.001), associated with a congestive and mature aspect of the parenchyma. Histologically a high incidence of chorioamnionitis (43 per cent) was found, contrasting with the absence of villitis. A relative villous hypercellularity was observed in the study group compared with the control group. Ultrastructural studies of 13 placentae corresponding to gestations of 10 to 40 weeks are presented. In six cases, retrovirus-like particles were found at various sites, such as villous fibroblasts, syncytiotrophoblast and endothelial cells, and in the free membranes.