Search PubMed⌕ Search

Biomedical subjects

Y Yaron

Publications and source records attributed to Y Yaron.

At least 73 records · Page 4Linked to original sources
PubMed1995

Ovarian hyperstimulation syndrome manifests as acute unilateral hydrothorax.

Ovarian hyperstimulation syndrome may be a serious complication of ovulation induction usually manifested by ovarian enlargement and ascites. In its severe form, haemoconcentration, oliguria and hydrothorax may ensue. As evident from this case report, the usual sequence of events does not necessarily occur in all cases. Unilateral hydrothorax may be the only extra-ovarian manifestation of ovarian hyperstimulation syndrome.

Adult↗
PubMed1995

Expectant management of ectopic pregnancy in the presence of ovarian hyperstimulation syndrome.

Cases of coexisting ovarian hyperstimulation and ectopic pregnancy are rare, and pose a difficult diagnostic problem. The routine attempts at laparoscopic diagnosis and treatment of these pregnancies may prove to be hazardous. Such cases may be better managed nonsurgically either by methotrexate or, in selected cases, by expectant management while monitoring the beta-hCG level and clinical status.

Adult↗
PubMed1995

High progesterone levels adversely affect embryo quality and pregnancy rates in in vitro fertilization and oocyte donation programs.

OBJECTIVE: To assess the effect of P levels on oocyte and embryo quality and pregnancy rates (PRs) in IVF and oocyte donation. DESIGN: Retrospective analysis of PRs in ovum donors and their recipients with regard to P levels on day of hCG administration. SETTING: In Vitro Fertilization Units, oocyte donation programs. PATIENTS: In vitro fertilization patients who agreed to donate oocytes were treated by hMG alone (53 cycles) or in combination with a GnRH analog (122 cycles). INTERVENTIONS: Uterine preparation in oocyte recipients consisted of 6 mg/d E2 valerate. Progesterone (100 mg/d) was added when oocytes became available. Hormonal treatment was continued until 12 weeks of gestation. RESULTS: Using a series of Fisher's Exact Tests, a critical threshold for P was identified at 1.9 ng/mL (conversion factor to SI units, 3.185). With elevated P levels (> 1.9 ng/mL), lower PRs were noted for the donors (7.1% versus 17%), as well for the recipients (8.3% versus 26.7%). CONCLUSIONS: Exposure to elevated P levels resulted in lower PRs for the donors and significantly lower PRs in the recipients. Because the endometria in the recipients were prepared uniformly, we conclude that this is the result of detrimental effects of P on oocyte or embryo quality.

Adult↗
PubMed1995

Extended induction of ovulation by human menopausal gonadotropins and a gonadotropin-releasing hormone analog in high responders for in vitro fertilization and oocyte donation.

OBJECTIVE: To examine the efficacy of extending ovulation induction for the in vivo maturation of oocytes. STUDY DESIGN: Fifty-nine high responders underwent 72 in vitro fertilization (IVF) cycles with a conventional protocol of human menopausal gonadotropin and a gonadotropin-releasing hormone analog. These patients donated oocytes to 81 recipients. The same 59 patients underwent 90 subsequent cycles in which the duration of induction was extended by two to three days. The oocytes were also donated to 138 patients. RESULTS: With the extended protocol, significantly more oocytes were retrieved (29.1 vs. 20.6), and a greater proportion of them were mature. Fertilization rates were significantly higher for both donors (67.7% vs. 36.2%) and recipients (67.5% vs. 47.1%). Conception rates were also significantly higher for both donors (24.4% vs. 11.1%) and recipients (38.4% vs. 24.7%). CONCLUSION: Extending the duration of ovulation induction in high responders is associated with in vivo maturation of oocytes and improved success rates in IVF and ovum-donation programs.

Administration, Intranasal↗
PubMed1994

Uterine rupture at 33 weeks' gestation subsequent to hysteroscopic uterine perforation.

A 40-year-old woman underwent operative hysteroscopy for suspected submucosal myoma, during which the uterine fundus was perforated. At laparotomy the perforation site was sutured. In a subsequent pregnancy she had a sudden onset of abdominal pain. Laparotomy revealed a uterine rupture with a partially protruding placenta. A healthy newborn was delivered by a low-segment cesarean section.

Adult↗
PubMed1994

Improved results in multifetal pregnancy reduction: a report of 72 cases.

OBJECTIVE: To evaluate pregnancy outcome after either transabdominal or transvaginal multifetal pregnancy reduction. DESIGN: A study of 72 consecutive multifetal pregnancy reductions. SETTING: Department of Obstetrics and Gynecology, The Chaim Sheba Medical Center Tel Hashomer, Israel. PATIENTS: Seventy-two patients with multifetal pregnancies: 2 twins, 27 triplets, 26 quadruplets, 10 quintuplets, 3 sextuplets, 1 septuplet, 2 nontuplets, and one pregnancy with 12 fetuses. INTERVENTION: Multifetal pregnancy reduction was performed at 9 to 13 weeks' gestation by either transabdominal or transvaginal potassium chloride injection. MAIN OUTCOME MEASURES: Early and late complications related to the procedure, outcome of pregnancy, and comparison of two periods. RESULTS: Procedures performed between 1984 and 1989 (36 patients) were associated with a 33.3% pregnancy loss, whereas those performed between 1990 and 1992 (36 patients) were associated with no pregnancy loss. Of the 17 patients with quintuplets or more, 10 (59%) delivered live and healthy newborns. No difference was found when comparing the transabdominal and the transvaginal approaches. CONCLUSIONS: Both transvaginal and transabdominal approaches are comparable. There is a remarkable decrease in pregnancy loss with experience.

Abortion, Therapeutic↗
PubMed1994

Outcome of donor versus husband insemination in couples with unexplained infertility treated by in vitro fertilization and embryo transfer.

OBJECTIVE: To examine the IVF-ET outcome of couples with unexplained infertility treated by husband versus donor sperm. DESIGN: A retrospective analysis of the IVF-ET outcome of couples with unexplained infertility treated by either husband or donor sperm and in a subgroup of patients treated simultaneously by husband and donor sperm. SETTING: IVF Unit, Serlin Maternity Hospital, Tel Aviv, Israel. PATIENTS: Couples diagnosed as having unexplained infertility underwent IVF at our Unit; included were 96 couples treated by husband insemination (group A), 27 couples who received donor insemination because of azoospermia (group B), and 8 couples who sought donor insemination after having previously failed IVF (group C). RESULTS: No statistically significant difference was found between groups A and B regarding age of the females, duration of infertility, number of IVF cycles, fertilization rate, number of ETs, and pregnancy rate. Oocytes collected in group C were subdivided further into two groups: 45 were incubated with husband sperm and 46 were incubated with donor sperm. Fertilization rates were 46.6% and 50%, respectively. One pregnancy occurred. CONCLUSION: In couples with unexplained infertility who had undergone IVF-ET with husband insemination, the fertilization and pregnancy rates were similar to those of couples who were treated by donor sperm.

Adult↗
PubMed1994

Endometrial receptivity in the light of modern assisted reproductive technologies.

OBJECTIVE: To review the different aspects of endometrial receptivity as it is reflected in the various modalities of modern assisted reproductive technologies. DESIGN: The importance of endometrial receptivity and the factors that affect it such as the type of treatment, age, and ovarian function are discussed in this review. Novel approaches to determine receptivity such as Doppler ultrasonography and molecular biology are considered; assisted hatching is also discussed. CONCLUSIONS: Endometrial receptivity cannot, as yet, be directly assessed. Circumstantial evidence suggests that receptivity declines with age, is adversely affected by controlled ovarian hyperstimulation, and is possibly affected by ovarian function. Future studies will have to focus on molecular cell biology and physiology of the endometrium.

Aging↗
PubMed1994

Circulating autoimmune antibodies may be responsible for implantation failure in in vitro fertilization.

OBJECTIVE: To investigate the role of autoimmune factors as a possible cause for implantation failure as manifested by chemical pregnancy after IVF and ET. DESIGN: Anticardiolipin, anti-double-stranded DNA (dsDNA), antinuclear antibody, lupus anticoagulant, and rheumatoid factor serum levels were examined in patients with chemical pregnancies and in matched controls. SETTING: An IVF unit, university-based IVF program. PATIENTS: The study group included 21 patients who had one or more chemical pregnancies and no deliveries. The control group consisted of 21 patients who had conceived and delivered after IVF-ET treatment, without any history of fetal wastage, matched for age, type and duration of infertility, and number of previous IVF cycles. RESULTS: The incidence of circulating autoimmune antibodies in the study group was 33.3% (7/21). Three patients (14.2%) were positive for anticardiolipin, two (9.5%) were positive for antidsDNA, one (4.7%) for antinuclear factor, and one (4.7%) for rheumatoid factor. Autoimmune antibodies were not detected in any of the control group. CONCLUSION: Autoimmunity may play a role in implantation failure in IVF-ET. Circulating autoimmune antibody screening is therefore recommended after chemical pregnancy.

Adult↗
PubMed1994

Analysis of the fourth to eighth in-vitro fertilization treatments after three previously failed attempts.

The fourth to eighth in-vitro fertilization cycles of patients who had previously reached the stage of embryo transfer without conceiving were evaluated. A total of 426 cycles were received in women ranging in age from 25 to 46 years. The patients underwent from four (169 women) to eight (27 women) treatment cycles, using four established protocols for induction of ovulation. There was no statistical difference in the age, aetiology, duration of infertility and distribution of the various protocols among the analysed groups. The pregnancy rates in cycles 4-8 were 19.5, 15.4, 10.8, 16.7 and 11.8% respectively (mean 16.2% per cycle) and were not statistically different. There was no trend of reduced success when the number of attempts increased. The overall live birth rate was 12.4%. The pregnancy rate was comparable between age groups. No protocol proved to be significantly superior to others when pregnancy rate per embryo transfer was assessed. We concluded that the pregnancy rate in cycles 4-8 was stable, including those of patients up to 42 years of age. Continuous efforts are therefore advised for at least up to this age and number of attempts. A change of an induction protocol in subsequent cycles, after repeated failure, is not statistically justified.

Adult↗
PubMed1994

Infected endometriotic cysts secondary to oocyte aspiration for in-vitro fertilization.

Two weeks after oocyte aspiration for in-vitro fertilization, a 38-year-old woman with a history of endometriosis presented with abdominal pain and fever. On exploratory laparotomy, both ovaries were enlarged and contained seropurulent fluid. Unilateral oophorectomy and drainage of the other ovary were performed. Pathological examination revealed infected endometriotic cysts.

Adult↗
PubMed1994

Tiggrin, a novel Drosophila extracellular matrix protein that functions as a ligand for Drosophila alpha PS2 beta PS integrins.

Genetic and other studies of Drosophila integrins have implicated these extracellular matrix receptors in various morphogenetic events, but identification of their endogenous ligands has been elusive. We report the biochemical purification and cloning of tiggrin, a novel extracellular matrix protein from Drosophila. This 255 x 10(3) M(r) polypeptide contains the potential integrin recognition sequence Arg-Gly-Asp (RGD) and 16 repeats of a novel 73-77 amino acid motif. The tiggrin gene is at chromosome locus 26D1-2 and is expressed by embryonic hemocytes and fat body cells. Tiggrin protein is detected in matrices, especially at muscle attachment sites that also strongly express integrins. Tiggrin-coated surfaces support primary embryo cell culture and provide excellent substrates for alpha PS2 beta PS integrin-mediated cell spreading. Soluble RGD-peptides inhibit this cell spreading.

Amino Acid Sequence↗
PubMed1993

Endometrial receptivity: the age-related decline in pregnancy rates and the effect of ovarian function.

OBJECTIVE: To assess the effect of age and ovarian function on endometrial receptivity. DESIGN: Retrospective comparison between standard IVF and ovum donation in younger and older patients (< 40 and > or = 40 years of age, respectively). PATIENTS: In standard IVF, there were 325 transfer cycles in older patients and 1,103 transfer cycles in younger ones. In ovum donation, there were 236 transfer cycles in older patients and 222 cycles in younger women. Ovum recipients were then redivided into two groups, according to ovarian function: ovarian failure group (219 cycles) and eugonadal group (239 cycles) in patients with retained ovarian function as manifested by regular menstrual cycles and normal gonadotropins. RESULTS: In standard IVF, clinical pregnancy rates (PRs) were significantly lower in older patients (12.9% versus 23.8%, respectively). In ovum donation, clinical PRs were also significantly lower in older patients (21.2% versus 29.3%, respectively). A significantly higher clinical PR (31.1%) was noted in patients with ovarian failure, compared with both eugonadal patients undergoing ovum donation (19.7%) and standard IVF patients (21.3%). CONCLUSIONS: The decrease in endometrial receptivity with age is responsible for the higher rate of implantation failure in older women. Patients with nonfunctioning ovaries do better than eugonadal patients in ovum donation programs.

Adult↗
PubMed1993

When multiple gestational sacs are seen on ultrasound, 'take-home baby' rate improves with in-vitro fertilization.

During a 5.5 year period, 309 clinical pregnancies were recorded in our in-vitro fertilization (IVF) unit. A single gestational sac was identified by early ultrasonography in 233 patients, while in 76 others, multiple gestational sacs were noted. 'Take-home baby' rate, in patients in whom multiple sacs were observed, was higher than that in patients with a single sac. Delivery of at least one live newborn occurred in only 73.8% of patients with a single sac, compared with 93.3% and 91.7% in patients with two and three gestational sacs, respectively. Conversely, the early and late abortion rates were decreased in patients with multiple sacs. Embryonic implantation rate, defined as the ratio of gestational sacs observed to the number of embryos transferred, was found to be a valuable prognostic factor for a live delivery, and can serve as a tool in assaying the prognosis of pregnancy detected by early sonography. The observation of a higher 'take-home baby' rate in cases with multiple sacs identified by ultrasound and with higher embryonic implantation rate, might be the result of a better embryo quality and/or improved uterine receptivity, promoted by a favourable hormonal milieu or by as yet unknown endometrial factors.

Abortion, Spontaneous↗
PubMed1993

Repeated aspiration of ovarian follicles and early corpus luteum cysts in an in-vitro fertilization programme reduces the risk of ovarian hyperstimulation syndrome in high responders.

A retrospective analysis of ovarian hyperstimulation syndrome in high responders undergoing in-vitro fertilization (IVF) is presented. High responders were defined as having > 20 follicles and serum oestradiol > 3000 pg/ml after treatment with human menopausal gonadotrophin. Of the initial 30 IVF cycles in high responders, 23 developed a moderate-to-severe ovarian hyperstimulation syndrome (76.7%). Subsequently, 15 other IVF cycles in high responders were combined with a repeated aspiration of ovarian follicles and corpus luteum cysts just prior to embryo transfer. Only three patients (20%) developed a moderate ovarian hyperstimulation syndrome (P = 0.0004). We conclude that repeated follicular aspiration is safe and results in a significant reduction in the incidence and severity of this condition in high responders undergoing IVF.

Adult↗
PubMed1993

Nifedipine versus ritodrine for suppression of preterm labour.

OBJECTIVE: To compare the efficacy of tocolysis with specific regimens of nifedipine and ritodrine. Maternal side effects and neonatal outcome also were evaluated. DESIGN: A prospective, randomised trial. SUBJECTS: Seventy-one women, including 11 with twin pregnancies, who had uterine contractions and observed cervical changes. MAIN OUTCOME MEASURES: Prolongation of pregnancy for 48 h, seven days and until 36 weeks of pregnancy were evaluated for each treatment. Maternal side effects and haemodynamic changes were compared, as well as neonatal outcomes. RESULTS: Delivery was delayed for 48 h, seven days, and until the 36th week of gestation in 83%, 67%, and 50%, respectively, of women in the nifedipine group, compared with 77%, 63% and 43%, respectively, of women in the ritodrine group (no significant difference). Maternal side effects were significantly less common in the ritodrine group (no significant difference). Maternal side effects were significantly less common in the nifedipine group (27%) than in the ritodrine group (77%) (P < 0.001). The neonatal outcome was similar in the two groups. The fall in mean arterial and diastolic blood pressure, and the rise in maternal heart rate were significantly greater in the women who received ritodrine compared with those treated with nifedipine. CONCLUSIONS: Nifedipine is as effective as ritodrine in suppressing preterm labour. Its use is associated with less frequent side effects.

Adult↗
PubMed1993

Embryonal reduction using transvaginal saline injection in a sextuplet pregnancy after ovulation induction with human menopausal gonadotropin.

A sextuplet pregnancy occurred in a first treatment cycle of ovulation induction with human menopausal gonadotropins. The serum 17-beta-estradiol concentration was 1245 pg/ml on the day of human chorionic gonadotropin administration. Embryonal reduction of four fetuses was carried out at nine weeks gestation using a transvaginal ultrasound-guided approach. Under general anesthesia, a 16-gauge in vitro fertilization needle was introduced through the posterior fornix and uterine wall, into the nearest gestational sac. The embryo was penetrated and 0.9% saline solution was injected until disintegration was noted, and confirmed by a lack of pulse for more than two minutes. The same procedure was applied to the three embryos in closest proximity to the needle. The patient delivered healthy twins in the 34th week of gestation after having had pre-term contractions for two weeks.

Abortion, Induced↗