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Biomedical subjects

A Amit

Publications and source records attributed to A Amit.

At least 55 records · Page 3Linked to original sources
PubMed1999

Anaerobic glycolysis. The metabolism of the preovulatory human oocyte.

OBJECTIVES: The aim of the study was to investigate the process of glycolysis in gonadotropic, hyperstimulated, human ovarian follicles. STUDY DESIGN: Follicular fluid (FF) lactate and glucose concentrations were measured in 26 patients with tubal factor infertility undergoing in vitro fertilization treatment. RESULTS: The mean FF lactate and glucose concentrations were 3.17+/-0.90 mM with positive, and 3.39+/-0.91 mM with negative correlations to follicular size. FF lactate concentration correlated negatively to glucose levels. CONCLUSIONS: Our study confirms in vivo the anaerobic glycolysis in gonadotropic, hyperstimulated human ovarian follicles.

Anaerobiosis↗
PubMed1999

The effect of isosorbide dinitrate on placental blood flow and maternal blood pressure in women with pregnancy induced hypertension.

The effect of isosorbide dinitrate (ISDN) on maternal and fetal circulation was assessed in 23 women with pregnancy induced hypertension (PIH). A double-blind randomized design was employed. Each woman was given a sublingual tablet of ISDN (5 mg) or placebo. Maternal blood pressure (BP) and heart rate (HR) were measured before and every 2 min after the medication or placebo, for a total of 20 min. Flow velocity waveforms in the uterine and umbilical arteries were recorded at the same time periods, using pulsed Doppler ultrasound. The ratio of peak systolic to end-diastolic flow velocity (S/D) in those vessels was calculated. After ISDN mean maternal BP fell from 103 +/- 1.8 mm Hg to 90.5 +/- 2.9 mm Hg at 14 min (P < .0001) and mean maternal HR increased from 97.3 +/- 3.8 beats/min to 115.7 +/- 3.5 beats/min at 12 min (P < .0001). The mean S/D in the umbilical artery fell from 3.07 +/- 0.33 to 2.58 +/- 0.23 at 8 min (P < .0007). The mean S/D in the uterine artery fell from 3.27 +/- 0.6 to 2.38 +/- 0.28 at 10 min (P < .0001). In seven of 12 women with an early diastolic notch in the uterine artery flow velocity waveform the notch diminished or disappeared within the first 6 min after the medication. No significant change in any of the measured parameters was observed in the placebo group. Our finding that ISDN altered maternal and fetal hemodynamics in PIH lends support to the further exploration of nitric oxide donors in the treatment and prevention of pregnancy induced hypertension.

Adult↗
PubMed1999

Pregnancy rate in IVF rescue in high responders to human menopausal gonadotropin.

PURPOSE: In vitro fertilization had been previously suggested by us as a means of "rescue" for patients with imminent ovarian hyperstimulation syndrome (OHSS) during treatment with human menopausal gonadotropin (hMG). We evaluated the pregnancy rate of rescued IVF cycles. METHODS: During the years 1994-1995, women treated with hMG and at risk of developing OHSS were referred to our IVF unit. Their estradiol level was above 1500 pg/ml, and eight or more follicles were observed by ultrasonography in all the patients. These high responders were offered the option to undergo ovum aspiration. We report the pregnancy rate in this group of patients. RESULTS: Thirty-nine women were referred to our unit for rescue IVF. Two were uneligible due to high progesterone concentrations. Thirty-seven women underwent ovum pickup and 32 had embryo transfer. The clinical pregnancy rate was 40% (13/32). Only two women had clinical OHSS. CONCLUSIONS: We suggest that rescue IVF may be considered in hMG cycles of high responders with imminent OHSS. Rescue IVF offers a high rate of conception, avoids high-order multiple pregnancy, and appears not to increase the risk of OHSS in these women.

Embryo Transfer↗
PubMed1999

Relationship between human sperm lipid peroxidation, comprehensive quality parameters and IVF outcome.

The membranes of human spermatozoa contain an extremely high concentration of polyunsaturated fatty acids and are therefore susceptible to lipid peroxidation damage. The aim of this study was to retrospectively determine the association between the lipid peroxidation levels of washed spermatozoa, as indicated by thiobarbituric-acid-reactive substance concentration, and: (a) semen quality evaluated by basic routine, biochemical, cytological and quantitative ultramorphological analyses; (b) IVF fertilization rate. Semen samples from 45 male partners of couples who had been referred for IVF treatment due to a female infertility factor were evaluated for quality as well as for thiobarbituric-acid-reactive substance concentrations. The latter were found to have a negative correlation with total sperm count, semen volume, zinc/fructose ratio, and the integrity of sperm acrosome and axonema. It was suggested that lipid peroxidation has a deleterious effect on the ultramorphological status of the sperm cells and, thereby, on the male fertilization potential. The content of the seminal fluid, about 30% of which is produced by the prostate, may protect spermatozoa from this destructive process. A negative correlation was also found between thiobarbituric-acid-reactive substance concentrations and IVF fertilization rate. When the patients were subdivided into fertilizing (fertilization rate > 0%) and nonfertilizing (fertilization rate = 0%) subgroups (n = 33 and n = 12, respectively), the former exhibited significantly lower thiobarbituric-acid-reactive substance concentrations than the latter. A new IVF fertilization index based on the lipid peroxidation level was established. This index had a predictive power of 93% (94% sensitivity and 92% specificity). The clinical value of this index should be further verified.

Female↗
PubMed1999

Do placentae of term singleton pregnancies obtained by assisted reproductive technologies differ from those of spontaneously conceived pregnancies?

The study was conducted to investigate the association of placental morphological and histopathological features with term, singleton pregnancies obtained by assisted reproductive technologies (ART). The study group comprised 45 consecutive women with a singleton pregnancy, obtained by ART, who delivered at term. For each subject in the study group, the consecutive, matched-for-age-and-parity woman, with a term singleton, spontaneously conceived pregnancy served as the controls. The placentae of both groups were subject to a detailed morphological and histopathological investigation by one pathologist, who was blinded to specimen origin. Pregnancy complications, fetal weight and perinatal outcome were similar in both groups. No differences in morphological or histopathological features of the placenta were observed between the groups. Nevertheless, the placentae of the study group showed a borderline, significantly higher placental weight and placental:fetal weight ratio, and placental thickness was significantly higher. Abnormal umbilical cord insertion was significantly more prevalent in the study group. Neither the specific ART method employed, nor the infertility factor affected the results, suggesting that multiple embryo transfers and/or ovulation induction protocols may account for these differences.

Adult↗
PubMed1999

Testicular sperm retrieval and cryopreservation prior to initiating ovarian stimulation as the first line approach in patients with non-obstructive azoospermia.

The potency for fertilization and successful implantation was compared between fresh and cryopreserved testicular spermatozoa obtained from the same patient with non-obstructive azoospermia. Spermatozoa cryopreserved at the outset were also evaluated. Non-obstructive azoospermic men (n = 55) underwent testicular sperm extraction (TESE); mature spermatozoa were found in 33 (60%) of them. Of 57 intracytoplasmic sperm injection (ICSI) cycles in 25 patients, 15 used fresh spermatozoa (14 patients, group 1), 24 used the excess spermatozoa cryopreserved after 'fresh' ICSI (11 couples who did not conceive in the 'fresh' cycle, group 2) and 18 cycles used cryopreserved spermatozoa at the outset (11 other patients, group 3). Fertilization, cleavage, embryo quality, implantation and take home baby rates were not significantly different in groups 1 and 2, and 6/14 couples ultimately had healthy babies (42.8% cumulative take home baby rate per TESE). In group 3, neither the fertilization rate, embryo development, pregnancy nor implantation rates per embryo transfer were significantly different from groups 1 and 2. The cumulative delivery and ongoing pregnancy rate in this group was 36. 4%. Cryopreservation did not impair the availability of motile spermatozoa for ICSI. When immotile spermatozoa were injected, however, fertilization rate decreased dramatically. Since criteria for predicting the presence of spermatozoa in the testicular tissue of patients with non-obstructive azoospermia are inadequate, it is suggested that TESE be performed prior to initiating ovarian stimulation.

Adult↗
PubMed1999

The possible role of antiovary antibodies in repeated in vitro fertilization failures.

PROBLEM: The study was conducted to investigate the possible role of circulating ovarian autoantibodies (ov-ab) in patients with repeated in vitro fertilization embryo transfer (IVF-ET) failure and to evaluate the effectiveness of immunosuppression treatment in these patients. METHOD OF STUDY: The study group comprised 80 IVF patients who had five or more failed treatment cycles (mean 10.2; range 7-22). The presence of ov-ab was compared between these women and 1) 50 IVF patients who conceived during the first three treatment cycles; 2) 50 healthy nulligravidae. All participants were seronegative to nonorgan-specific and antithyroid autoantibodies. Patients in the study group who were positive for ov-ab were treated with 10 mg/day prednisone starting 1 month before ovulation induction. Embryo grading was compared in the IVF cycles before and after treatment. RESULTS: Ov-ab were found in ten patients (12.5%) in the study group, compared to none in the control groups (P = 0.01). Nine of the patients positive for ov-ab were treated with prednisone for their following cycle. A statistically significant improvement in embryo grading was noted. Three patients conceived after treatment (33%), with a take-home baby rate of 22%, compared to only six patients (8.6%) who conceived among the rest of the seronegative study group, with a take-home baby rate of 7.1% (P = 0.05). CONCLUSIONS: Ov-ab are a possible marker of an autoimmune disorder that may be one of the causes of repeated IVF failures. Immunosuppression treatment may prove efficient in ov-ab seropositive patients with repeated IVF failures by improving embryo grading and pregnancy rate.

Adult↗
PubMed1999

Follicular fluid levels of vascular endothelial growth factor. Are they predictive markers for ovarian hyperstimulation syndrome?

OBJECTIVE: To determine the possible predictive role of vascular endothelial growth factor (VEGF) levels in the follicular fluid (FF) at the time of oocyte retrieval in the development of ovarian hyperstimulation syndrome (OHSS) and its possible origin. STUDY DESIGN: FF was obtained from 174 high-responder patients at the time of oocyte retrieval. The study group comprised 16 high-responder patients who developed early, severe OHSS and from whom serum and peritoneal fluid (PF) were obtained during the active phase of the syndrome. These women were compared to 16 high-responder patients who did not develop OHSS. An additional control group comprised 16 low-responder patients who also did not develop OHSS. The FF, serum and PF samples were tested for VEGF by enzymelined immunosorbent assay. RESULTS: No differences in the FF VEGF levels were found among the OHSS group (1,742.3 +/- 522.4 pg/mL), the high-responder group that did not develop OHSS (1,802.0 +/- 584.3 pg/mL) and the low-responder group (1,686.7 +/- 374.2 pg/mL). In the OHSS group, no differences were found between the serum and PF VEGF levels (247.3 +/- 31.4 and 642.9 +/- 328.3 pg/mL, respectively). No correlation was found between the FF concentrations of VEGF and the mean serum 17-beta estradiol levels or number of oocytes retrieved. CONCLUSION: We conclude that preovulatory FF levels should not serve as a possible predictive factor for development of OHSS. The increased capillary permeability found in OHSS may be due to its systemic effect.

Case-Control Studies↗
PubMed1998

Multifetal pregnancy reduction: a possible risk factor for periventricular leukomalacia in premature newborns.

OBJECTIVE: To investigate the possible role of multifetal pregnancy reduction as a risk factor for the development of periventricular leukomalacia, which has been associated with prematurity and twin pregnancies. DESIGN: A case-control study. SETTING: In Vitro Fertilization Unit and Intensive Care Nursery of the Tel Aviv Sourasky Medical Center, Tel Aviv, Israel. PATIENT(S): A total of 1,401 consecutive preterm infants who were born between January 1, 1994, and December 31, 1995. INTERVENTION(S): Cranial ultrasonographic evaluation of each infant within 3 days of birth. MAIN OUTCOME MEASURE(S): Premature infants who developed periventricular leukomalacia (cases) were compared with premature infants who did not develop this disorder (controls) when multifetal pregnancy reduction was considered. RESULT(S): Fourteen premature infants developed periventricular leukomalacia. Of these, 28.6% (4 infants) were exposed to multifetal pregnancy reduction, compared with 1.9% of the controls, giving an odds ratio (OR) of 20.9 (95% confidence interval [CI] 5.5-79.4). Adjustment of this OR for IVF treatment (OR, 18.6; 95% CI, 1.8-140.3), twinning (OR, 6.3; 95% CI, 1.3-30.3), and for both IVF treatment and twinning simultaneously (OR, 8.5; 95% CI, 1.7-42.2) did not explain all the observed associations between periventricular leukomalacia and multifetal pregnancy reduction. CONCLUSION(S): Our data suggest that multifetal pregnancy reduction may be an additional risk factor for periventricular leukomalacia among premature infants, regardless of twinning.

Adult↗
PubMed1998

The effect of a nitric oxide donor on Doppler flow velocity waveforms in the uterine artery during the first trimester of pregnancy.

Our objectives were to study the effect of a nitric oxide donor on uterine blood flow velocity waveforms and maternal heart rate and blood pressure during the first trimester of pregnancy. Eleven women were examined at 8-12 weeks' gestation, prior to elective termination of pregnancy. Each woman was randomly given a sublingual tablet containing 5 mg of isosorbide dinitrate or placebo, on two consecutive days. Measurements of maternal blood pressure, heart rate and Doppler flow velocity waveforms of the ascending branch of the main uterine artery were obtained before, and every 2 min (for 20 min) after taking the drug or placebo. Following administration of isosorbide dinitrate, the mean arterial blood pressure fell from a control value of 82.5 +/- 5.6 mmHg to a nadir of 73 +/- 4.1 mmHg at 16 min (p < 0.0001). The mean maternal heart rate increased from a control value of 80.9 +/- 2.8 beats/min to a peak of 90.4 +/- 4.6 beats/min at 10 min (p < 0.001). The mean resistance index in the uterine artery fell from a control value of 0.80 +/- 0.02 to a nadir of 0.73 +/- 0.03 at 10 min (p < 0.0001). Analysis of covariance was employed to compensate for the effect of heart rate on the resistance index. The drug had a significant effect on the resistance index in the uterine artery, independent of maternal heart rate. These results suggest that drugs such as isosorbide dinitrate may have a potential benefit under such conditions where the production of nitric oxide (i.e. endothelium-derived relaxing factor) is decreased.

Adult↗
PubMed1998

Multiple testicular sampling in non-obstructive azoospermia--is it necessary?

Spermatogenesis may be focal in non-obstructive azoospermia. The present study was conducted to determine whether the performance of multiple, rather than a single testicular sample contributes to obtaining spermatozoa in amounts sufficient for fertilization and cryopreservation in non-obstructive, azoospermic patients. Furthermore, the aim was to clarify the significance of location for retrieval from the testis in such cases. Three biopsies were taken from identical locations in 55 testes of 29 men with non-obstructive azoospermia: (i) the rete testis region, ii) the midline, and (iii) the proximal region of the testis. When sperm cells were detected, they were used for intracytoplasmic sperm injection (ICSI), and the remainder were then cryopreserved in as many aliquots as possible (adjusted for ICSI procedure). Spermatozoa were found in 28 testes (50.9%) of 18 men (62.1%). In the testes from which spermatozoa were obtained, they were present in three, two or one locations in 15 (53.6%), five (17.9%) and eight (28.6%) cases respectively. The possibility of finding spermatozoa was not influenced by the location in the testis. Multiple testicular sperm extraction is recommended in cases of non-obstructive azoospermia, since it may enhance diagnostic accuracy of absolute testicular failure and increase the number of sperm cells retrieved.

Adult↗
PubMed1998

Oocyte donation in Israel: a study of 1001 initiated treatment cycles.

There are numerous studies concerning pregnancy rates in oocyte donation, yet only a handful report the obstetric outcome in such pregnancies. The purpose of this study was to assess factors that influence pregnancy rates, to determine the incidence of complications, and to evaluate obstetric outcome in pregnancies resulting from oocyte donation. This study included 423 oocyte recipients who underwent 1001 oocyte donation cycles at the Oocyte Donation Programme, In-Vitro Fertilization (IVF)-Embryo Transfer Unit, Herzlia Medical Center, Israel. Donors were all healthy women < 34 years old who underwent IVF themselves. In 873 cycles, fertilization occurred and embryo transfer was performed, resulting in 194 clinical pregnancies. Pregnancy rates (PR) significantly declined with the increase in number of previous attempts, and with increasing age of recipient (36.8%/embryo transfer in patients < or = 30 compared to 17.8% in patients > 40 years old). A significant increment in PR was noted with the increasing number of embryos transferred. The overall PR was 22.2%/embryo transfer. However, in young amenorrhoeic patients with normal karyotypes undergoing their first cycle, PR was 52.2%; the 'take home baby' rate was 38.3% per patient undergoing embryo transfer and 17.8% per embryo transfer cycle. A significant increase in the incidence of pregnancy-induced hypertension and a higher proportion of abortions were noted in older patients. A significantly higher incidence of prematurity and low birthweight was observed in multiple pregnancies.

Adult↗
PubMed1998

A 3 year, prospectively-designed study of late selective multifetal pregnancy reduction.

The aim of our study was to evaluate the pregnancy outcomes of late selective multifetal reduction (MFPR). We performed a 3 year, prospectively-designed study in which 28 patients underwent MFPR at a mean gestational age of 20.2 +/- 3.9 weeks (range 14-29 weeks). The indications for MFPR included: multiple gestation (> or = 3) (57%), structural anomaly (29%), and chromosomal abnormality (14%). The procedure was performed using ultrasonographically-guided intracardiac injection of potassium chloride. The mean gestational age at delivery was 36.6 +/- 2.2 weeks (range 31-40 weeks). Nine patients (32%) delivered before 36 weeks of gestation. The mean birth weight was 2370 +/- 614 g (range 1510-3250 g). Discordancy was evident in four twins (14%), and intrauterine growth retardation in four pregnancies. One case (3.5%) presented with oligohydramnios, and one with pregnancy-induced hypertension. One case of late abortion due to passive cervical dilatation 4 weeks after the MFPR was observed. Procedure-related amnionitis followed by late abortion occurred in one case. A total of 57% of the patients delivered vaginally and 43% delivered by Caesarean section. We concluded that late selective MFPR is associated with favourable perinatal outcome. Late MFPR may facilitate the detection of structural and chromosomal anomalies prior to the procedure, and the accomplishment of selective reduction of the affected fetus.

Abortion, Spontaneous↗
PubMed1998

High levels of anticardiolipin antibodies in patients with abnormal embryo morphology who attended an in vitro fertilization program.

PROBLEM: Recently, it has been suggested that anticardiolipin antibodies (ACAs) may serve as possible markers for reproductive failure. The association between ACAs and embryo morphology in patients undergoing in vitro fertilization (IVF) was investigated. METHOD OF STUDY: This prospective study comprised 117 patients with either tubal factor or unexplained infertility. Embryo morphology was blindly scored from I to IV according to blastomere regularity and the presence of fragments. Anticardiolipin antibodies (immunoglobulin [Ig] G and IgM) were detected. RESULTS: Anticardiolipin antibodies were found in 26 (50%) of the 52 patients with abnormal morphology, compared with 13 (20%) of the 65 patients with normal embryo morphology (P = 0.001). No statistically significant differences were found between the prevalence of ACAs among patients with tubal factor and those with unexplained infertility (29.6% and 36.5%, respectively). CONCLUSIONS: Our study shows an association between embryo morphology and the presence of ACAs. This association may explain the low implantation rate and early pregnancy loss in patients with ACAs.

Antibodies, Anticardiolipin↗