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Biomedical subjects

A Amit

Publications and source records attributed to A Amit.

At least 109 records · Page 6Linked to original sources
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

Native gonadotropin-releasing hormone for triggering follicular maturation in polycystic ovary syndrome patients undergoing human menopausal gonadotropin ovulation induction.

OBJECTIVE: To evaluate the role of GnRH administration instead of hCG for triggering follicular maturation in patients with polycystic ovaries (PCO) undergoing hMG ovulation induction when the late follicular 17-beta-E2 levels are > 1,600 pg/mL (> 6,000 pmol/L). DESIGN: Prospective study. SETTING: Infertility outpatient clinic of Rambam Medical Center (general hospital), Haifa, Israel. PATIENTS AND INTERVENTIONS: High serum E2 concentrations from 1,600 to > 3,600 pg/mL (2,800 +/- 68, mean +/- SD [6,000 to > 13,000 pmol/L, 10,279 +/- 2,500]) were experienced in 44 hMG cycles. The number of preovulatory follicles visualized by transvaginal sonography was between 8 and 25. An IV injection of 200 micrograms GnRH was administered for triggering final follicular maturation and ovulation, instead of 10,000 IU IM hCG, usually injected for this purpose, when the E2 levels are < or = 1,600 pg/mL (6,000 pmol/L). Serum E2 and P levels were monitored in the luteal phase. In cycles where E2 decreased to < or = 1,360 pg/mL (5,000 pmol/L), 2,500 IU hCG was administered once or twice at 3-day intervals for luteal support. MAIN OUTCOME MEASURES: Pregnancy and abortion rates and the rate of ovarian hyperstimulation syndrome (OHSS). RESULTS: Ten pregnancies were generated by the hMG and GnRH co-treatment in 32 patients (31.2%), in 44 cycles (23%). Two pregnancies aborted (20%), and eight generated eight healthy neonates. Ovarian hyperstimulation syndrome occurred in two cycles of patients who were both pregnant. All but two of these PCO patients also have undergone 69 hMG and hCG cycles. Only 7 patients conceived (23%) 10 times (10/69, 14.5%); 5 of these pregnancies (50%) were multiple gestations (3 twins, 1 sextuplet, and 1 heptuplet gestation). The pregnancy wastage rate was 30% (3/10). CONCLUSION: The use of native GnRH to trigger ovulation in PCO patients with late follicular E2 levels > 1,600 pg/mL (6,000 pmol/L) appears to be comparable with prior hMG and hCG cycles in terms of pregnancy rate, pregnancy wastage, risk of multiple gestation, and incidence of severe ovarian hyperstimulation. Unlike hMG and GnRH-agonist, which is associated with luteal phase dysfunction, hMG and GnRH offers a preferable alternative due to the ability of hCG luteal support and rescue, providing the E2 levels are not dangerously increased.

Estradiol↗
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

The hemizona assay is of good prognostic value for the ability of sperm to fertilize oocytes in vitro.

OBJECTIVES: To assess the prognostic value of hemizona assay (HZA) in predicting the success of IVF. DESIGN: Samples from 133 patients, who were referred for semen evaluation, were tested by HZA. Thirty samples were tested twice to assess interassay variation. Seventy couples were also referred for IVF. Results of HZA were compared with standard parameters of sperm quality, fertilization rates, and pregnancies. RESULTS: The intra-assay and interassay coefficient of variation were 8% and 14%, respectively. Hemizona assay results had the highest correlation with sperm morphology (r = 0.60). Of all parameters evaluated, fertilization rates were best predicted by hemizona index (HZI) (r = 0.75). The assay was found to have high sensitivity and specificity rates, at a threshold HZI of 23%. CONCLUSIONS: The HZA is a valuable prognostic test for IVF. With a threshold HZI of 23%, it has a good predictive value for fertilization rates in IVF, and may thus be used for patient preselection before IVF.

Female↗
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↗
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

[New methods for predicting sperm fertilizing ability].

There is no reliable method for screening for the fertilizing ability of sperm. 3 new methods are presented: the freezing test (FT), hypoosmotic swelling test (HOST) and migration-sedimentation test (MST). The first 2, test the functional integrity and stability of the sperm membrane under certain osmotic conditions. The MST determines ability to separate high quality sperm. All tests were performed using either fresh semen of husbands, or thawed semen of donors used for fertilization in the IVF unit. Results of the FT were not correlated with the fertilizing ability of sperm in IVF, but HOST results with fresh, but not thawed semen, were correlated. Fertilization of oocytes in IVF was significantly better when HOST value of fresh semen was 45% or more. Motility and morphological normality of sperm separated by MST were better in ejaculates that fertilized ova under in vitro conditions, than in those that did not. Sperm separation by MST of 25% or more of motile sperm, or of more than 1.5 million motile sperm in the sample, indicated statistically significant ability for oocyte fertilization in an IVF system.

Cell Membrane↗
PubMed1993

[Comparison of ovulation induction protocols for in vitro fertilization].

In a retrospective study we evaluated 4 controlled ovarian hyperstimulation (COH) protocols for in vitro fertilization (IVF) treatment. Treatment cycles 4 through 8 were analyzed in patients, who in 3 previous attempts reached the stage of embryo transfer (ET) but did not conceive. The 426 recorded cycles included all indications for IVF, but not the male factor. The age range was 25-46 years. Patients underwent from 4 cycles (169 women) to 8 cycles (27 women). The COH protocols used included established combinations of menotropins, clomiphene citrate/hMG, and short and long protocols of GnRH analogs followed by hMG. There were no statistically significant differences in patient age, etiology and duration of infertility, or distribution of the various COH protocols among the groups of patients. No single protocol was significantly superior to any other when the pregnancy rate per cycle was assessed. The results did not justify changing a COH protocol which had lead to ET but not to pregnancy, for another protocol.

Adolescent↗
PubMed1992

The predictive fertilization value of the hypoosmotic swelling test (HOST) for fresh and cryopreserved sperm.

BACKGROUND: The hypoosmotic swelling test (HOST) was recommended as a predictive test for in vitro fertilization (IVF) outcome. These results, however, were controversial and the results for thawed semen were insufficient. The present study was conducted in order to clarify the predictive value of the HOST for IVF in fresh and thawed sperm. METHODS: The hypoosmotic swelling test was performed in three groups: husband's fresh semen "subfertile" group, donor's thawed semen group, and donor's fresh semen "fertile" group. RESULTS: No correlation was found between HOST values and sperm characteristics in fresh or thawed sperm. Fresh sperm HOST values correlated with IVF fertilizations. No such correlations were found when thawed sperm was used. HOST values were significantly higher in the fresh fertile donor group than in the fresh subfertile group (P less than 0.001). Following the freezing and thawing process, HOST values decreased dramatically. Nevertheless, the fertilization rate was still higher compared to that of the fresh subfertile group (P less than 0.001). There were significantly more IVF cycles with no fertilizations when HOST values were below 45%. CONCLUSION: The HOST has a predictive value for fertilization of oocytes in IVF cycles when fresh semen, but not thawed sperm, is used. The freezing-thawing process affects the outer membrane of the spermatozoon and changes its characteristics, leading to a decrease in HOST values. Sperm characteristics that play a role in the fertilization process are not expressed directly by HOST values.

Cell Membrane↗
PubMed1992

High initial values of beta-subunits of human chorionic gonadotropin in ovum donation pregnancies indicate better implantation.

Fifty-five patients were treated by ovum donation, and a control group of 165 patients underwent IVF. The number of pregnancies obtained were 28 and 25, respectively. The initial beta-hCG values, as well as the PRs and implantation rates, in the ovum donation series were significantly higher than those of the IVF series. The clinical significance and potential application of these observations are discussed.

Chorionic Gonadotropin↗
PubMed1992

Improved fertilization rate in an in vitro fertilization program by egg yolk-treated sperm.

High fertilization and PRs have been achieved by using thawed donor sperm cryopreserved with medium containing EY. The aim of our study was to examine the possible effect of EY on the fertilizing capacity of fresh sperm in an IVF program. Preincubation of spermatozoa in EY for 2 hours at room temperature significantly improved fertilization (P less than 0.001) in couples who had low fertilization rates in previous cycles, whereas no effect was found concerning couples with high fertilization rates.

Egg Proteins↗
PubMed1992

Embryo reduction in multifetal pregnancies using saline injection: comparison between the transvaginal and the transabdominal approach.

A total of 30 patients with multifetal pregnancies, all resulting from treatment with superovulatory agents or assisted reproductive techniques, underwent embryo reduction. All patients had three or more fetuses (one sextuplet, two quintuplets, seven quadruplets and 20 triplets). The procedure was carried out using intra-embryonal injection of 0.9% sodium chloride solution. Embryo reduction was carried out via the transabdominal approach in 10 patients, performed at 11-12 weeks of gestation, and via the transvaginal route in 20 other patients, at 8-10 weeks of gestation. In the transabdominal group, one patient aborted following repeated attempts at embryo reduction while the other nine gave birth to healthy newborns (eight twins and one triplet). In the transvaginal group, four pregnancies are currently ongoing (all beyond 28 weeks of gestation), 14 pregnancies resulted in a delivery of at least one live newborn (13 twins and one singleton), one patient had a late abortion at 24 weeks' gestation and another was delivered at 27 weeks' gestation due to severe pre-eclampsia. Transvaginal ultrasound-guided needle procedures are commonly practised in most in-vitro fertilization units. The employment of this route for embryo reduction, performed at an earlier gestational age and with the use of a non-toxic substance such as 0.9% saline solution, is advocated.

Abdomen↗
PubMed1992

Migration sedimentation technique as a predictive test for the fertilizing capacity of spermatozoa in an in-vitro fertilization programme.

The migration-sedimentation technique (MST) has been proposed as a means of separating high quality motile spermatozoa. The present study was conducted in order to evaluate whether sperm performance following separation by MST predicts their fertilizing capacity in an in-vitro fertilization (IVF) programme. Ninety semen specimens were analysed for use in an IVF-embryo transfer (ET) programme. Each specimens was divided into two parts: one was processed in the IVF programme and was used after sperm swim-up separation for insemination of human ova. The other aliquot (0.2 ml) was separated by MST, and the sperm then characterized by their concentration, motility, degree of motility and morphology. Sperm characteristics after separation by MST were then correlated with the results of the IVF-fertilization rates. In 79 of 90 IVF-ET cycles, at least one oocyte was fertilized. All post-MST sperm characteristics were significantly higher in cycles with fertilizations compared to IVF cycles without fertilization. A larger percentage of the total motile spermatozoa were recovered after MST in semen specimens with fertilization, compared to semen specimens without fertilization (39.9 +/- 3.6 and 20.6 +/- 6.6%, respectively; P < 0.05). This value was correlated with the percentage of fertilized oocytes (r = 0.24; P < 0.02). More IVF cycles with fertilizations were recorded in cases in which the recovery of motile sperm was > 25% (P < 0.005), or when more than 1.5 x 10(6) motile spermatozoa were recovered after MST (P < 0.0001). As sperm characteristics after MST correlated significantly with their fertilizing capacity, the MST test could be used in evaluation of the fertilizing capacity of spermatozoa.

Cell Separation↗
PubMed1992

Spontaneous fetal reduction in multiple gestations assessed by transvaginal ultrasound.

OBJECTIVE: To assess the occurrence of disappearance of one or more of the fetuses in pregnancies which start as multiple gestation. DESIGN: Observational study. SETTING: Infertility section, Rambam Hospital, Haifa. SUBJECTS: 88 women with multiple gestations, established after ovulation induction (54 twin, 26 triplet, five quadruplet, and three quintuplet) and diagnosed by transvaginal ultrasound at 5-6 weeks, in all of whom absorption of at least one gestation sac was detected at follow-up ultrasound scan. INTERVENTIONS: Follow-up by serial transvaginal and later abdominal ultrasound scan throughout pregnancy. RESULTS: Of the 54 twin gestations, 51 ended in the birth of a singleton and three in miscarriage. Of the 26 pregnancies starting as triplets, 12 ended in singleton births, 12 in twins and two miscarried. The five quadruplet gestations resulted in one singleton birth, one set of twins, two triplets, and one ended in late miscarriage. Of the three quintuplet pregnancies, two resulted in the birth of triplets, one of them after spontaneous, the other after iatrogenic fetal reduction. In the third quintuplet pregnancy, one fetus vanished spontaneously and another was subject to iatrogenic reduction, two fetuses survived and were liveborn. Of the 221 fetuses identified 107 (48%) vanished spontaneously. CONCLUSION: Iatrogenic fetal reduction should be delayed until 12 weeks gestation in quadruplet or higher multiple gestations, but is probably not indicated in twin and triplet gestations.

Adult↗