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Y Englert

Publications and source records attributed to Y Englert.

At least 73 records · Page 4Linked to original sources
PubMed1996

Is intracytoplasmic sperm injection (ICSI) a safe procedure? What do we learn from early pregnancy data about ICSI?

The aim of this study was to evaluate the safety of the intracytoplasmic sperm injection (ICSI) procedure by analysing early pregnancy data from ICSI and in-vitro fertilization (IVF) patients. In all, 50 ICSI pregnancies were compared with 226 IVF pregnancies. Comparisons were made during the first 9 weeks after the theoretical last menstrual period (7 weeks after oocyte retrieval) with regard to epidemiological data, plasma hormonal concentrations and transvaginal ultrasonographical findings. Although patients were significantly (P < 0.001) younger in ICSI (31 years) than in IVF pregnancies (33 years), their duration of infertility was similar. Miscarriage and multiple gestation rates were not significantly different in ICSI pregnancies (respectively 24 and 24%) from those found after IVF (32 and 29%). The probability of developmental arrest of the intrauterine sac (miscarriages and vanishing twins) was similar in both ICSI (16%) and IVF (25%) cases. The mean plasma hormonal concentrations starting from day 11 after oocyte retrieval were similar in both groups. Every ICSI and IVF pregnancy showed an embryo with cardiac activity at 7 weeks. Early pregnancy data did not show any abnormal findings for pregnancies achieved using ICSI compared to those achieved by IVF.

Abortion, Therapeutic↗
PubMed1996

Oocyte shortage for donation may be overcome in a programme with anonymous permutation of related donors.

Difficulty in recruiting donors plays a crucial role in oocyte donation programmes. We report here an original strategy to overcome this problem, consisting of sharing out anonymous oocytes between recipients, which has markedly improved treatment efficiency by avoiding freezing or destruction of supernumerary embryos. Each patient received part of the supply of oocytes from several donors in four successive cycles, while each donor underwent oocyte retrieval only once. This strategy led to one pregnancy per treated donor, increased treatment efficacy by 300%, and reduced dramatically the oocyte shortage at our centre. The system avoids wastage of the rare and precious donated oocytes, increases the chance of pregnancy for each related recipient and even permits the inclusion of some recipients without related donors.

Adult↗
PubMed1996

Periovulatory elevation of angiotensin II in the peritoneal fluid during the human menstrual cycle.

Local variations in the ovarian renin-angiotensin system were investigated in peritoneal fluid (PF) during normal menstrual cycles and after ovarian stimulation with gonadotropins. PF was collected either during laparoscopy or by transvaginal aspiration before ovocyte retrieval for in vitro fertilization. Renin activity (RA) and angiotensin II immunoreactivity (Ang II-ir) were assayed in PF and simultaneously collected blood. The level of Ang II-ir was higher in PF than in plasma throughout the cycle, where as RA was in the same range of magnitude in the two compartments. In PF, Ang II-ir reached levels 2-5 times higher in the periovulatory period (days 12-14 and 15-17 of the cycle) than those found during the other stages of the cycle, whereas plasmatic Ang II-ir remained stable. No significant change could be demonstrated in RA throughout the cycle in either PF or plasma. Ovarian stimulation induced a strong elevation of Ang II-ir in PF, but not in plasma. High performance liquid chromatography revealed that the majority of Ang II-ir in PF was true Ang II. In conclusion, these results show a periovulatory elevation of Ang II in PF during the cycle and a more pronounced rise after treatment with gonadotropins. These observations support the involvement of Ang II in the process of ovulation or fecundation.

Adult↗
PubMed1996

The long-acting gonadotropin-releasing hormone analogues impaired the implantation rate.

OBJECTIVES: To determine the efficacy and innocuousness of long-acting versus short-acting GnRH analogues (GnRH-a) in long protocol for in IVF-ET. DESIGN: Prospective randomized study. SETTING: The IVF unit at an academic hospital. PATIENTS: One hundred couples admitted for their first IVF-ET attempt. MAIN OUTCOME MEASURES: Serum concentrations of LH, E2, and P during the all cycles and duration of pituitary desensitization were assessed, as well as fertilization rate, embryo quality, and implantation and pregnancy rates. RESULTS: Significantly more days (10.8 +/- 1.8 versus 9.2 +/- 1.7 days) of stimulation and more ampules of hMG (47 +/- 22 versus 33 +/- 16) were necessary to obtain similar numbers of embryos of quality with the long-acting GnRH-a. Implantation and delivery rates were significantly lower with the long-acting GnRH-a (32.8% versus 21.1%; 48.9% versus 29.1%, respectively). CONCLUSIONS: As the long-acting GnRH-a might interfere with the luteal phase and embryo development, short-acting GnRH-a should be preferred for ovarian hyperstimulation in IVF-ET.

Adult↗
PubMed1996

Clinical parameters influencing human zona pellucida thickness.

OBJECTIVES: To assess which clinical parameters influence human oocyte zona pellucida (ZP) thickness. PATIENTS: Sixty-five couples undergoing 75 IVF-ET cycles. MAIN OUTCOME MEASURE: Zona pellucida thickness of 827 oocytes measured 16 to 20 hours after in vitro insemination under inverted light microscope. RESULTS: Zona pellucida thickness was 18.9 +/- 3.8 microns (mean +/- SD) for unfertilized, 16.4 +/- 3.1 microns for fertilized, and 15.1 +/- 2.4 microns for polyspermic oocytes (significantly different). Among our patients, a few underwent two (or even three) IVF-ET cycles, and the mean ZP thickness was, in most cases, not significantly different from one cycle to the other(s). Regression analyses were calculated between ZP thickness and available clinical parameters, i.e., the age of the women, the duration of stimulation, the cumulus maturity, the number of retrieved oocytes, the number of hMG doses, the maximum E2 level, and the follicular volume. A significant linear decreasing relationship exists between the mean ZP thickness of each patient and the maximum E2 level and an increasing one with the hMG dose. Relationships with the other parameters appeared to be nonsignificant. CONCLUSION: The ZP thickness is basically an individual feature that influences the fertilization rate. Nevertheless, it may be influenced slightly by the hormonal treatment during stimulation.

Adult↗
PubMed1996

[Fate of supernumerary embryos and risk of multiple pregnancy in in-vitro fertilization: attitude of involved couples].

To determine the fate of their possible additional embryos and to face the multiple pregnancy risk are problems each couple undergoing in vitro fertilization is confronted. The supernumerary embryos can be frozen but the couple have to decide before the treatment the fate of the possible embryos that would not be transferred at the end of the storage period. The opinion of 236 couples concerning these questions were evaluated through a questionnaire and an interview. Ninety-eight percent chose for their embryos to be frozen. Despite the fact that they frequently designed donation as the ideal choice only half of them chose that issue. To give priority to educational aspects in parental bonding led them to accept for their embryos to become children in another couple. On the contrary, if the couple's opinions focused on genetic aspects, they would regard these children as their own. In this case they opted for destruction or experimentation (in both cases the embryos will be finally destroyed), even if they consider that the in vitro embryo is already a child. The statue of the embryo do not interfere with the choice for the fate of the supernumerary embryos. Religion, to have children already, and the project to adopt in case of treatment failure did not influence their choice. Regarding the possible multiple pregnancy risk, couples attitude differs from twins to triplets. Twins are nearly always accepted and even considered by one-third of patients a suitable result for the treatment. On the opposite, one-third refuse the perspective of triplets. Fourteen percent of couples declare in this case they would ask for fetal reduction.

Attitude↗
PubMed1996

[Evaluation of methods of sperm preparation for human in vitro fertilization].

OBJECTIVES: Compare results of sperm prepared with centrifiguation-migration, percoll discontinuous gradient (50, 70, 90%) and migration-sedimentation. METHODS: An aliquot of sperm collected from 125 men referred for infertility was prepared according to the three methods. The spermogram after preparation and extration rates were compared using the Student's t test for paired variables and for three subpopulations identified by increasing spermatozoid concentrations. RESULTS: Sperm count were significantly higher after percoll. Mobility and morphology were improved after centrifugation-migration excepting for the samples with the lowest counts. The extration rate was better after percoll and rose for the low-count samples. CONCLUSION: Percoll gradient is the most effective method, particularly for altered sperm. The number of mobile and normal forms can be improved with the centrifugation-migration technique.

Centrifugation↗
PubMed1995

Second polar body extrusion is highly predictive for oocyte fertilization as soon as 3 hr after intracytoplasmic sperm injection (ICSI).

OBJECTIVE: Our objective was to evaluate the time course and the predictive value of the extrusion of the second polar body after intracytoplasmic injection (ICSI) related to the fertilization rate, embryo cleavage and quality. SETTING: The setting was the in vitro fertilization program of a university hospital. PATIENTS: Twenty-one patients were treated with intracytoplasmic single sperm injection either for fertilization failure in IVF, low fertilization in IVF (< 5%), or severe male factors. DESIGN: One hundred thirty-five of 205 metaphase 2 oocytes treated with intracytoplasmic single sperm injection were observed 1, 2, and 3 hr after the assisted fertilization procedure. Extrusion of the second polar body was recorded. For each of these oocytes, fertilization was noted 18 hr after ICSI and cleavage and embryo quality were assessed 24 hr later. The 70 remaining oocytes were used to assess a possible negative effect of repeated exposure to light microscopy. RESULTS: The extrusion of the second polar body 3 hr after injection was an observation with a sensitivity of 0.87, a specificity of 0.58, and a high positive predictive value (0.90) toward oocyte fertilization. Twenty-nine and four-tenths percent of the oocytes extruded a second polar body within the first hour, 56.6% within the first 2 hr, and 78.3% had a second polar body 3 hr after injection. This time course was related neither to the speed of embryo cleavage nor to the embryo quality. Fertilization, cleavage, and embryo quality were not affected by repeated observation as deduced from comparison with the control group and confirmed by a high pregnancy (62% per oocyte retrieval) and implantation rate (22% per replaced embryo). CONCLUSION: Oocytes can be checked, in all safety, 3 hr after a single sperm injection for the presence of a second polar to predict oocyte fertilization with a high certainty.

Chorionic Gonadotropin↗
PubMed1995

Psychological study of in vitro fertilization-embryo transfer participants' attitudes toward the destiny of their supernumerary embryos.

OBJECTIVE: To study the motivations underlying IVF-ET participants' choice to donate or destroy their supernumerary embryos. DESIGN: Couples' opinions are studied through a questionnaire and a psychological interview. PARTICIPANTS: Two hundred couples about to undergo IVF-ET. SETTING: The fertility unit of an academic hospital. MAIN OUTCOME MEASURES: Couples' choice for supernumerary embryos' destiny; opinions on embryo status, on importance of genetic lineage in the filial bonding, on gamete donation, and on multiple pregnancy risk. RESULTS: Donation is the most frequent choice but destruction is tolerated by almost all the couples (92%). Couples considering the embryo as a child choose destruction as frequently as donation but refuse experimentation on the embryo. Donation is highest among couples who stress education more than genetic lineage in parental bonding. This is confirmed by the choice of the couples requiring donor gametes. Couples express differing attitudes toward risks of twins and risks of triplets: twins are much more desired than triplets, which are frequently refused. CONCLUSIONS: Couples' opinions on the respective importance of genetic lineage and education in defining parental bonding are more determinant in their decision to destroy or to donate their supernumerary embryos than their opinions on the in vitro embryo status, which only determines their attitude toward experimentation.

Attitude↗
PubMed1995

Does zona pellucida thickness influence the fertilization rate?

In human in-vitro fertilization (IVF), the cumulus oophorus is routinely removed to assess fertilization and hence the thickness of the zona pellucida is measurable. This study aimed to measure the thickness of the zona pellucida and to assess its influence on fertilization rate in IVF programmes. The zona pellucida thickness varies from 10 to 31 microns with a mean of 17.5 microns. One-way analysis of variance revealed that in IVF trials performed with normal semen, the zona pellucida of fertilized oocytes (16.6 +/- 3.2 microns) was significantly thinner than the zona pellucida of unfertilized oocytes (18.9 +/- 4.0 microns; P < 0.001). As measured on micro-injected oocytes, the zona pellucida thickness did not change between ovulation and 16-20 h after fertilization. Zona pellucida thickness was not related to ooplasm diameter. In conclusion, zona pellucida thickness appears to be an additional factor that should be taken into account when interpreting the fertilization rate. Zona pellucida thickness influences sperm penetration, even when the spermatozoa are considered normal. From a clinical point of view, a thick zona pellucida (> or = 22 microns) could be an indicator for the use of micro-injection procedures.

Adult↗
PubMed1995

[Update on ovarian hyperstimulation syndrome].

The ovarian hyperstimulation syndrome (OHSS) is the most important complication of the pharmacological ovulation induction. Exclusively postovulatory, it is clinically characterized by a massive ovarian enlargement associated with an acute third-space fluid shift responsible for the development of ascites, and sometimes pleural and/or pericardial effusion. While mild OHSS has no consequence, severe forms can be life-threatening because of associated hemodynamic troubles. The main risk factors are the polycystic ovarian syndrome and an explosive ovarian response to the stimulation characterized by high serum oestradiol levels and an increased number of follicles. Ultrasound and endocrine monitoring make prevention measures possible, mainly by either abandoning the stimulation cycle or, during in vitro fertilization, cryopreserving the embryos for subsequent replacement in another cycle. Treatment consists in correcting circulatory and electrolyte imbalance. Paracentesis is more and more systematically proposed in the severe forms.

Ascites↗
PubMed1995

[Preclinical trials for mastering intracytoplasmic injection of a sole spermatozoid for the treatment of male infertility].

Before starting with the clinical application of ICS, aged unfertilized oocytes were gathered for training and were injected with a single sperm or without a spermatozoon as a control group for activation. Oocyte damage, initially as high as 40% was reduced to 15% after 60 oocytes. Normal fertilization (2PN) occurred in 18% of the injected oocytes. After this training period 1,488 metaphase II oocytes collected during 144 cycles were used for ICSI. Results were split up in 3 periods (n = 55, n = 24, n = 57) corresponding to the different improvements made in the technique. Results form ICSI in combination with MESA (n = 6) were analysed separately. Mean fertilization increased from 24% to 77%. Fertilization failures (18% of the cycles during the first period) vanished in the last period. Implantation rate improved from 7.4% to 11.4% and reached finally 26%. Pregnancy rate per oocyte retrieval was 16%, 25% and 54%. For the MESA group fertilization was 28%, implantation rate 17% and pregnancy rate 33% and only one fertilization failure was observed. A total of 50 pregnancies were obtained including 2 obtained after MESA and 2 with cryopreserved embryos. Four healthy children are born, 9 were early abortions, 37 pregnancies are still on-going. Preclinical practice on aged unfertilized oocytes seems useful before starting with clinical ICSI, as high initial oocyte damage could be reduced and subsequent clinical treatment successfully applied. Offering high fertilization and pregnancy rates in cases of infertility with severe male factor it is extremely worthwhile mastering this new technique.

Cytoplasm↗
PubMed1995

[Assisted procreation: ethics and passions].

In vitro fertilization has become a subject of major ethical debate filled with passion and for two main reasons: On the one hand, it has posed in a very clear way the problem of the status of the human embryo, a problem intrinsically related to the debate on the voluntary termination of pregnancy. On the other hand, it looks again at the debate on access to these techniques, to the legitimacy of the desire for a child and to debate on the new families and from there, questions sexuality, life and death, subjects of fundamental existence. The authors analyses the phenomenon, develops a lay approach to embryo status and from there defends a vision of freedom of access to assisted procreation.

Abortion, Induced↗
PubMed1994

Intracytoplasmic single sperm injection: preclinical training and first clinical results.

OBJECTIVE: Our purpose was to reduce oocyte damage before clinical application of intracytoplasmic single sperm injection by training on aged unfertilized oocytes. DESIGN: Intracytoplasmic single sperm injection (ICSI) was accomplished by micromanipulation of sperm and oocytes. PATIENTS: Thirty-four patients consented to donate unfertilized aged oocytes to train for ICSI. Forty-four patients suffering from severe male infertility were treated with ICSI. INTERVENTION: Oocytes were inseminated by intracytoplasmic single sperm injection. MAIN OUTCOME MEASURES: Oocyte damage and fertilization and pregnancy rates were the outcome measures. RESULTS: One hundred fifty-one aged unfertilized oocytes were gathered for training of which 121 were injected with a single sperm and 30 without a spermatozoon as a control group for activation. Oocyte damage, initially as high as 40%, was reduced to 15% after 60 oocytes. Normal fertilization (2PN) occurred in 18%, and polyploidy in 4.4%. The cleavage rate was 69%; none of these embryos were transferred. In the control group, seven oocytes were damaged, seven (30%) showed one pronucleus, and one showed two pronuclei. No cleavage was observed in the control group. In the clinical trial, 44 patients (61 cycles) were clinically treated with the same ICSI procedure, including 575 of 721 collected oocytes. Damage was 13%, activation was 11%, normal fertilization was 30%, and 5 (1%) polypoid zygotes were observed. The fertilization rate ranged from 5 to 100%, with a mean of 39.5 +/- 4% (SE). Nine patients had no fertilization (15%). Ninety-six percent of the zygotes cleaved and 47% were at the four-cell stage 45 hr after injection. One hundred twelve embryos were replaced in 48 transfers (2.3 embryos/ET). One live birth, one miscarriage, and eight ongoing pregnancies were obtained (22%/ET). CONCLUSION: Preclinical practice on aged unfertilized oocytes seems useful before starting clinical ICSI, as the high initial oocyte damage can be reduced and subsequent clinical treatment successfully applied.

Cell Survival↗