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Biomedical subjects

I Ben-Nun

Publications and source records attributed to I Ben-Nun.

At least 19 recordsLinked to original sources
PubMed1997

The role of a human chorionic gonadotropin burst in in vitro fertilization.

FINDINGS: No oocytes were found during four ovum pickups (OPU), despite a satisfactory ovarian response to controlled ovarian hyperstimulation. After the first attempt failed in the fourth case, five eggs were retrieved, fertilized, and cleaved after cycle rescue with hCG. CONCLUSIONS: Whenever oocytes are not aspirated during OPU due to a lack of hCG administration, the cycle may be rescued if 10,000 IU of hCG is injected immediately and OPU planned for 33-36 hr later.

Adult↗
PubMed1997

Induction of artificial endometrial cycles with s.c. oestrogen implants and injectable progesterone in in-vitro fertilization treatment with donated oocytes: a preliminary report.

Endometrial preparation for embryo implantation in oocyte recipients with retained ovarian function presents a special problem. In all, 10 women with preserved ovarian function received donated oocytes in an in-vitro fertilization programme. In the preparatory cycles with oral oestrogens, all failed to develop adequate secretory endometrium because of ill-timed early luteinization occurring during the proliferative phase of the cycle. Subsequently the patients were treated with s.c. 17-beta oestradiol implants and injectable progesterone. The implants successfully induced complete down-regulation of the hypothalamus, pituitary axis, and prevented luteinizing hormone (LH) surge. In these preparatory cycles, all the treated patients produced adequate secretory endometrium. Clinical trials of 27 oocyte donation cycles yielded one biochemical and eight clinical pregnancies.

Adult↗
PubMed1996

The significance of an early (premature) rise of plasma progesterone in in vitro fertilization cycles induced by a "long protocol" of gonadotropin releasing hormone analogue and human menopausal gonadotropins.

OBJECTIVE: Our purpose was to assess and clarify the mechanism of whether an early progesterone rise in cycles with gonadotropin-releasing hormone agonist (GnRH-a) is associated with an impairment of IVF outcome. METHODS: Seven hundred eighty-six cycles were induced with GnRH-a and human menopausal gonodotropin (hMG) ("long protocol"). Plasma progesterone (PP) levels on the day of human chorionic gonadotropin (hCG) administration were divided into three groups: < 0.9 ng/ml (Group A), 1-2 ng/ml (Group B), and > 2 ng/ml (Group C). We also analyzed the pregnancies achieved in our egg donation protocol in relation to the PP levels of each donor on the day of hCG administration. RESULTS: Group A involved 525 cycles, Group B had 223, and Group C had 38. The overall pregnancy rate per egg transfer was 19.2%, with the highest for Group A (22.3%), declining for Groups B (14.3%) and C (7.9%) (A = B = C; P < 0.005). The embryo implantation rate was found to be negatively correlated with the PP levels on the day of hCG administration. In contrast, there was an opposite trend between PP levels and the chance of conception in 30 pregnancies achieved by egg donation. CONCLUSION: Since premature luteinization is very unlikely to occur under the conditions of this study, our findings suggest that an early PP rise has a negative impact on endometrial receptivity but not on egg and embryo quality.

Adult↗
PubMed1995

The impact of different types of anesthesia on in vitro fertilization-embryo transfer treatment outcome.

OBJECTIVE: Our objective was to evaluate retrospectively the influence of different types of anesthesia on the outcome of ovum retrieval. METHODS: Sedation combined with local anesthesia was used on 120 occasions (Group I), epidural block in 139 ovum retrievals (Group II), and general anesthesia in 173 cycles (Group III). RESULTS: No differences were found in embryo yield or number or the quality of the embryo transferred. Of 99 pregnancies achieved, 66 live deliveries were recorded. Significantly lower clinical pregnancy rates were found in Group III (14.5%) compared with Group II (23.7%; P = 0.018) or Group I (25.8%; P = 0.0074). Highly significant differences were found in the delivery rates between Group III (8.7%), Group II (20.11%; P = 0.0017), and Group I (19.2%; P = 0.0043). CONCLUSION: The use of general anesthesia, especially nitrous oxide, for oocyte retrieval has an adverse effect on IVF outcome. This deleterious effect manifests itself only after embryo transfer and leads to lower pregnancy and delivery rates.

Adult↗
PubMed1995

Relationship between the threshold of ovarian sensitivity to human menopausal gonadotrophin stimulation and in-vitro fertilization treatment outcome.

In a retrospective study of 813 oocyte retrieval-embryo transfer cycles in women with normal follicle stimulating hormone and luteinizing hormone concentrations, we sought to investigate the relationship between the amount of human menopausal gonadotrophin (HMG) used for ovarian stimulation and treatment outcome. Patients were divided into three groups: group A patients (495 cycles) required < 40 ampoules of HMG and had a predicted probability for pregnancy of 25% per embryo transfer; group B patients (165 cycles) required 41-77 ampoules per cycle, with a predicted probability rate for pregnancy of 5-25% per embryo transfer; and group C patients (153 cycles) required > 77 ampoules of HMG and the predicted probability for pregnancy was < 5% per embryo transfer. Groups C and A differed significantly (P < 0.005). The mean oestradiol concentration on the day of HCG administration in group C was 6412 pmol/l, and the mean number of eggs retrieved was seven. The highest success rates were found when up to 2.5 ampoules of HMG were required for each egg or 4.4 ampoules for each embryo. The lowest rates were obtained when > 4.8 ampoules of HMG were necessary for each oocyte or > 9.6 ampoules for each embryo (P < 0.005). We identified a group of infertile patients who required excessive amounts of HMG to achieve a fair degree of steroidogenesis, number of eggs and number of embryos but who had very low pregnancy rates. Although all other relevant parameters were normal, this may highlight the beginning of ovarian-gamete insufficiency before the basic hormonal status is affected. In cases of repeated failure, oocyte donation should be considered.

Drug Resistance↗
PubMed1995

Induction of artificial endometrial cycles with oestradiol implants and injectable progesterone: establishment of a viable pregnancy in a woman with 17-alpha-hydroxylase deficiency.

Repeated attempts with oral oestrogens and injectable progesterone failed to induce secretory endometrium in a woman with 17-alpha-hydroxylase deficiency. The insertion of s.c. 17-beta-oestradiol implants dramatically improved the endometrial response and enabled the establishment of endometrial maturation. A viable pregnancy was achieved after the uterine transfer of in-vitro fertilized donated eggs.

Adrenal Hyperplasia, Congenital↗
PubMed1994

The significance of plasma progesterone levels during early pregnancies achieved after in vitro fertilization (IVF) treatment.

OBJECTIVE: Corpus luteum steroidogenesis is lower for in vivo ectopic pregnancy than for intrauterine pregnancy. There is a progesterone hallmark level distinguishing between viable intrauterine pregnancy and nonviable or ectopic pregnancy. This study attempts to answer whether this is also true for in vitro fertilization-treated patients. STUDY DESIGN: Using information retrieved from a computerized database, we compared the plasma 17 beta-estradiol (E2) and progesterone during the luteal phase and for every 2 to 3 days for several weeks during early pregnancy between those patients with proven ectopic pregnancies and those with singleton and multiple intrauterine pregnancies. Vaginal ultrasonography to detect an intrauterine gestational sac was performed from day 19. A total of 73 pregnancies resulted from the replacement of fresh embryos in our in vitro fertilization-embryo transfer program. RESULTS: Only at day 10 post embryo transfer did those patients with ectopic pregnancy show statistically lower mean (SD) serum levels of E2 [2257 (SD, 2351) pmol/L] and plasma progesterone [PP; 221 (SD, 283) nmol/L] compared with patients with intrauterine pregnancy, whose mean E2 was 8846 (SD, 5871) pmol/L and mean PP was 805 (SD, 582) nmol/L (P = 0.008). For the rest of the follow-up until surgery was performed in ectopic pregnancy, there were no differences of statistical significance between extrauterine pregnancy and the intrauterine pregnancy groups. Furthermore, only on day 10 post embryo transfer, did we find a discriminatory zone (confidence interval, 95%) for E2 levels (903 to 3502 pmol/L for EP vs 6116 to 9493 pmol/L for a singleton and 4875 to 9493 pmol/L for multiple pregnancies). PP levels were 26 to 283 nmol/L for ectopic pregnancy versus 496 to 1096 nmol/L for both singleton and multiple pregnancies. An intrauterine gestational sac was visualized at a mean of 23.2 (SD, 4) days after embryo transfer. On this day, the mean P levels were 982.6 (SD, 286.2) nmol/L for intrauterine and 804.5 (SD, 502.4) nmol/L for ectopic pregnancies (P = NS). CONCLUSIONS: Except for day 10 post embryo transfer, the steroidogenesis in ectopic pregnancy after in vitro fertilization treatment does not differ from successful intrauterine pregnancy. This observation negates an impaired steroidogenesis for ectopic pregnancy after in vitro fertilization and makes the PP level irrelevant in the diagnosis of pregnancy implantation.

Chorionic Gonadotropin↗
PubMed1994

Ovarian cyst formation in two pre-menopausal patients treated with tamoxifen for breast cancer.

Pre-menopausal tamoxifen treatment causes hyperoestrogen production and ovarian cyst formation. Two pre-menopausal breast cancer patients who were treated with tamoxifen developed both permanent supraphysiological oestrogen concentration and ovarian cysts. Serum oestrogen decreased to post-menopausal concentrations and ovarian cysts completely resolved during and following simultaneous treatment with tamoxifen and gonadotrophin-releasing hormone agonist (GnRHa). In pre-menopausal breast cancer patients, GnRHa may prevent possible side-effects of tamoxifen, such as ovarian cysts and supraphysiological oestrogen production.

Adult↗
PubMed1994

Distribution of carbohydrates in the zona pellucida of human oocytes.

The purpose of the present study was to investigate the distribution pattern of carbohydrates in the zona pellucida of human oocytes using lectins and ruthenium red as histochemical probes. For lectin analyses, oocytes that failed to undergo fertilization following in vitro insemination were collected, washed, fixed with glutaraldehyde and embedded in araldite. For ruthenium red labelling, the oocytes were fixed with glutaraldehyde containing ruthenium red, post-fixed with OsO4 and embedded in araldite. Araldite sections (1 micron) were de-resined with sodium methoxide, rehydrated, labelled with ten different biotinylated lectins as probes and avidin-biotin-peroxidase complex as visualant, and examined under a light microscope. The zonae pellucidae of all oocytes studied exhibited a common lectin-binding pattern, expressed in intense binding of lectins from Concanavalia ensiformis (ConA), Lens culinaris (LCA), Ricinus communis (RCA-I), wheat germ agglutinin (WGA), and of succinylated WGA (S-WGA). Peanut lectin (PNA) bound to the zona pellucida only after neuraminidase treatment, whereas the lectins from Griffonia simplisifolia (GS-I), Dolichos biflorus (DBA), Ulex europhaeus (UEA-I) and soybean (SBA) did not bind at all. There was almost no binding of ruthenium red to the matrix of the zona pellucida. The results indicate that the human zona pellucida is characterized by normally exposed mannosyl, N-acetylglucosaminyl and beta-galactosyl residues. In addition, it contains masked beta Gal-(1-3)GalNAc sugar sequences that can be exposed only after removing terminal sialic acid residues.(ABSTRACT TRUNCATED AT 250 WORDS)

Carbohydrates↗
PubMed1994

Once a cerclage, not always a cerclage.

A study was performed to evaluate the outcome of pregnancies in which the decision was not to repeat cerclage in women with a doubtful indication for the previous one. Thirty-five women with a history of at least one previous McDonald cerclage were followed prospectively. Pregnancy complications and outcome were compared to those in the previous pregnancy with a cerclage. These patients had 58 pregnancies with a cerclage and 52 pregnancies without. The pregnancies without a cerclage had fewer complications, were longer and resulted in the delivery of significantly larger infants (P < .05). Whereas all 52 cumulative pregnancies without a cerclage had a favorable outcome, there were nine perinatal losses in the 58 pregnancies with a cerclage (P < .05). The decision not to repeat a cervical cerclage, when the grounds for the previous procedure are doubtful, is a safe one.

Female↗
PubMed1993

The correlation between the frequency of sister-chromatid exchange and human reproductive hormones.

Different frequencies of sister-chromatid exchanges (SCEs) during various stages of the menstrual cycle have previously been observed. We tested the hypothesis that sex hormones, particularly steroids, influence the frequency of SCEs in women undergoing ovulation induction for in vitro fertilization treatment. These women undergo extreme hormonal changes and therefore serve as a good model for testing the rate of genetic damage due to these changes. As controls, we tested fertile women with regular menstrual cycles who received no hormonal treatment. Peripheral lymphocytes were obtained during different stages of the normal and treated cycles. We examined SCE frequency as related to the different hormones of the reproductive cycle at each of the stages. In general, an increased SCE frequency was observed around ovulation time in the controls, and around the time of human chorionic gonadotropin administration in the group undergoing ovulation induction. However, in the latter group, SCE frequency was significantly higher. SCE frequency was positively correlated with the level of testosterone and FSH in the ovulation induction group, and positively correlated with the estradiol level in both groups.

Adult↗
PubMed1993

Relationship between embryo morphology and implantation rate after in vitro fertilization treatment in conception cycles.

OBJECTIVE: To investigate the relationship between the embryo number and morphology in conception cycles and the incidence of multiple pregnancies. DESIGN: The study is based on information received from a computerized data base. SETTING: In Vitro Fertilization Unit, Sapir Medical Center, Kfar Saba, Israel. PATIENTS: A total of 117 consecutive pregnancies resulted from replacement of fresh embryos in our IVF-ET program. MAIN OUTCOME MEASURES: The impact of embryo quality, as assessed by morphological parameters, on the multiple pregnancy rate (PR). RESULTS: Implantation rates positively correlated with the number and the quality of transferred embryos. However, no multiple pregnancies occurred when only two embryos were replaced. There were no multiple pregnancies when only embryos of low quality (grades 1 and 2) were transferred. Furthermore, there was no correlation between the number of replaced embryos of poor quality and the rate of implantation. The multiple PR increased from 10% when a mixture of high and low quality embryos were transferred to 30.76% when only embryos of highest quality were transferred. CONCLUSION: The implantation rate of transferred embryos is directly correlated with the morphological scoring. The results of the study suggest that the number of embryos transferred should be balanced against their morphological quality to reduce the rate of multiple pregnancies.

Adult↗
PubMed1993

The inability of preovulatory ovarian scan to predict multifetal pregnancy occurrence in a follow-up of induction of ovulation with menotropins.

OBJECTIVE: To establish the predictive role of preovulatory ovarian ultrasonography in the occurrence of multiple pregnancy after hMG and hCG treatment for anovulatory infertility. DESIGN: Prospective. SETTING: Outpatient Infertility Clinic. PATIENTS: Ninety-five anovulatory women who conceived after gonadotropin therapy. INTERVENTION: Induction of ovulation by hMG and hCG monitored by plasma E2 measurements and ovarian ultrasonography. MAIN OUTCOME MEASURES: All follicles visualized on the day of hCG administration were recorded and divided into the following four groups: group I, 10 to 12 mm; group II, 13 to 15 mm; group III, 16 to 18 mm; and group IV, 19 mm and larger. The sonographic findings were statistically evaluated to 80 singletons and 45 multiple pregnancies. RESULTS: No statistical correlation was found to exist between the number of follicles from the different groups and the number of fetuses. CONCLUSIONS: The number and sizes of follicles visualized on the day of hCG administration have no predictive value regarding the occurrence of a multiple pregnancy.

Adult↗
PubMed1992

Lack of correlation between hormonal blood levels and endometrial maturation in agonadal women with repeat implantation failure following embryo transfer from donated eggs.

Five women with ovarian failure who repeatedly failed to conceive following embryo transfer from donated eggs underwent endometrial development investigation. One endometrial biopsy was obtained on cycle days 19, 21, and 23 during three consecutive artificially induced cycles. All five patients had only early secretory changes on days 19 and 21. Histological evaluation on cycle day 23 revealed various developmental stages: two women had "in-phase" endometrium, two patients had adequately developed stroma but significantly retarded glandular maturation, and one women showed no progress. The histological findings were conclusive for a significant maturation delay and an impaired endometrial receptivity. There was a lack of correlation between the peripheral hormonal blood levels and the endometrial maturation.

Abortion, Spontaneous↗