Subzonal insertion, a possible treatment for "defective oocytes".
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Adult↗
Biomedical subjects
N Laufer
Publications and source records attributed to N Laufer.
A new rapid method of producing microneedles for subzonal sperm insertion.
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Fertilization in Vitro↗
Ovulation induction in polycystic ovary syndrome: a review of conservative and new treatment modalities.
Polycystic ovary syndrome (PCOS) is a complex disorder with heterogeneous clinical and endocrine features. Chronic anovulation and infertility are common and affect about 75% of the patients. Ovulation induction in PCOS patients is a challenge for the physicians who treat these patients. Several different treatment modalities have been proposed to induce ovulation in PCOS, each of which deals with a different clinical or endocrine disorder which is present in these patients. This review presents traditional and new methods for ovulation induction in PCOS patients, the theoretical background, the pros and cons for each treatment and success rate.
Clomiphene↗
Conception rate after in vitro fertilization in patients who conceived in a previous cycle.
OBJECTIVE: To evaluate whether a previously successful in vitro fertilization and embryo transfer (IVF-ET) cycle is a favorable prognostic factor for a subsequent cycle. DESIGN: A retrospective comparison between current IVF patients who have previously conceived in an IVF versus natural cycle. SETTING: The IVF unit of a university hospital. PATIENTS: Group A consisted of 51 patients (70 cycles of IVF-ET) who previously conceived in an IVF-ET cycle, and group B included 141 patients (201 cycles of IVF-ET) who previously conceived in a natural cycle. All couples with male factor infertility were excluded. Ovulation induction protocol was identical for both groups and consisted of gonadotropin-releasing hormone agonist pretreatment followed by gonadotropin stimulation. MAIN OUTCOME MEASURES: Pregnancy rate per ET, cumulative pregnancy rate, and livebirth rate in both groups. RESULTS: The following parameters were comparable for both groups: age, menotropin dosage required for an adequate stimulation, ovarian response, mean number of oocytes retrieved per cycle, fertilization and cleavage rates, and the mean number of embryo transferred. Group A attained a significantly higher pregnancy rate (PR) than group B (31.4% versus 19.4%). Group A also achieved a significantly higher livebirth rate (22.9% versus 11.4%) than group B. Similarly, the cumulative PR curves and the cumulative livebirth rate curves for three consecutive IVF-ET cycles differed significantly between the two groups. CONCLUSION: A previous successful IVF cycle is a positive prognostic factor for a repeated IVF attempt. This effect could be because of either an improved endometrial response or a better embryo quality. It may be that this patient population is relatively immune to the known untoward effects of ovulation induction on endometrial development and, therefore, may represent a potential clinical model that can be used to further identify the factors influencing uterine receptivity after ovulation induction.
Adult↗
The efficacy and safety of zona pellucida drilling by a 193-nm excimer laser.
OBJECTIVE: To examine the efficiency of argon fluoride excimer laser drilling of the zona pellucida of mouse oocytes in improving in vitro fertilization (IVF) at low sperm concentrations and to assess its safety. DESIGN: Oocytes obtained from (Balb/c x C57BL6)CB6F1 female mice were drilled by laser and divided into two groups: group I (89 oocytes) were inseminated with 10(5) sperm cells/mL, and group II (94 oocytes) were inseminated with 10(6) sperm cells/mL. Both groups' fertilization rate and development in vitro was compared with control oocytes that underwent the same preparation steps but no drilling (94 and 88 oocytes for group I and group II, respectively). MAIN OUTCOME MEASURES: The fertilization rate and the development in vitro of the laser-drilled groups is compared with that of the control. In addition, in vivo development of embryos generated from laser-drilled oocytes after transfer to pseudopregnant recipients is assessed. RESULTS: For both sperm concentrations, laser drilling significantly enhanced fertilization over control (67% versus 31% at 10(5) sperm cells/mL and 90% versus 54% at 10(6) sperm cells/mL). The development into the blastocyst stage after 96 hours of incubation was similar for both the laser-drilled and control groups at any sperm cell concentration. However, complete hatching at this point was significantly enhanced by the drilling procedure. Normal litters were obtained from the transfer of embryos developed from zona-drilled oocytes into pseudopregnant recipients. CONCLUSIONS: Excimer laser drilling enhanced IVF at low sperm cell concentration. The procedure is safe and did not interfere with embryo development in vitro or in vivo.
Animals↗
The effect of gonadotropin-releasing hormone agonist on embryo quality and pregnancy rate following cryopreservation.
OBJECTIVE: To examine the effect of GnRH analogue (GnRH-a) on the quality of frozen-thawed embryos and the pregnancy rate (PR) resulting from transfer. DESIGN: A retrospective study of two groups of women undergoing transfers of frozen-thawed embryos. In group 1 ovulation induction with hMG was begun after hypophyseal desensitization with GnRH-a for 2 weeks. In group 2 ovulation was induced with hMG only. The freezing and thawing techniques were identical for both groups. SETTING: In vitro fertilization unit at a university hospital. PATIENTS: The study group (group 1) included 108 women who underwent 137 transfer cycles of frozen-thawed embryos, and the control group (group 2) included 44 women in 51 cycles of thawed ETs. INTERVENTIONS: Ovum pick-up and ET techniques were the same for both groups. Methods of embryo freezing and thawing were identical, as were the morphological criteria for grading the embryos. RESULTS: The morphology of embryos was similar in both groups, as was the number of embryos that had at least 50% intact blastomeres (83% +/- 23% and 78% +/- 30% for group 1 and group 2, respectively). The PR (16 of 137 [11.7%] and 6 of 51 [11.8%], respectively) as well as the abortion rate (30%) were similar for both groups. CONCLUSIONS: The use of GnRH-a does not affect the quality of embryos nor the pregnancy outcome. Because the yield of frozen embryos per ovum pick-up is higher in cycles stimulated by GnRH-a/hMG, the PR per pick-up cycle is thus anticipated to be higher.
Abortion, Spontaneous↗
Novel parameters of human sperm hypoosmotic swelling test and their correlation to standard spermatogram, total motile sperm fraction, and sperm penetration assay.
OBJECTIVE: To improve the accuracy of human sperm hypoosmotic swelling test by introducing new morphological evaluation parameters for this test. DESIGN: Individual semen samples were processed, and the standard spermatogram, total motile sperm fraction, sperm penetration assay (SPA), and hypoosmotic swelling test were performed. SETTING: Male infertility clinic and andrologic laboratory in a university medical center. PATIENTS: One hundred eighteen subfertile men undergoing an infertility work-up. MAIN OUTCOME MEASURES: The results of hypoosmotic swelling test were subdivided into four groups (hypoosmotic swelling test 1, 2, 3, 4) according to the different shapes of hypoosmotically affected spermatozoa tails. RESULTS: The hypoosmotic swelling test 3 had the best correlation with the different sperm parameters: motility, total motile sperm fraction, concentration, and SPA. The hypoosmotic swelling test 1 showed a satisfactory interrelation for concentration and for total motile sperm fraction but no correlation for motility and SPA. The hypoosmotic swelling test 2 and the hypoosmotic swelling test 4 demonstrated no correlation at all with motility, concentration, morphology and SPA. CONCLUSIONS: The precision of hypoosmotic swelling test may be improved by using the hypoosmotic swelling test 3 type of spermatozoa tail shape as the parameter for a normally functioning spermatozoa.
Female↗
Interaction between human sperm cells and hamster oocytes after argon fluoride excimer laser drilling of the zona pellucida.
OBJECTIVES: To provide conclusive evidence that sperm cells gain access to the perivitelline space exclusively through a laser-drilled opening. To assess the optimal size of the hole and to evaluate the efficacy of laser drilling in comparison with that of mechanical zona dissection. DESIGN: An interspecies model of human sperm cell that interacts with a laser-drilled or partially zona-dissected hamster oocytes. MAIN OUTCOME MEASURES: Penetration rate into the perivitelline space as related to the size of the opening (group A [5 microns], group B [10 microns], and group C [15 microns]) and to the sperm cell concentrations (1 x 10(6), 5 x 10(6), and 10 x 10(6) cells/mL) used for insemination. RESULTS: For each sperm cell concentration, the penetration rate into the perivitelline space was lowest for group A followed by group C and highest for group B. When penetration was compared for each hole size, it was found that sperm concentration had no effect on the rate of penetration in groups A and C but significantly affected this rate in group B. The highest penetration rate of 73% was observed with a concentration of 10 x 10(6) cell/mL and declined to 58% and 23% at 5 x 10(6) cell/mL and 1 x 10(6) cell/mL, respectively. Oocytes drilled by laser (10-microns hole) demonstrated a significantly higher penetration rate when compared with those treated by partial zona dissection (73% versus 20% and 58% versus 21% for sperm densities of 10 x 10(6) cells/mL and 5 x 10(6) cells/mL, respectively). CONCLUSION: Human sperm cells gain access into the perivitelline space of hamster oocytes exclusively through a hole drilled by an argon fluoride excimer laser. An opening of 10 microns was found to yield optimal results. Laser drilling of the zona pellucida seems to be superior to that of mechanical slitting in terms of sperm oolema interaction.
Animals↗
Elective suture of uterine cervix in triplets.
The incidence of triplet pregnancies has increased several times due to the widespread use of ovulation induction agents. Premature delivery is the main complication of triplet gestations. In twin conceptions it was shown definitely that elective cervical suture does not prolong these pregnancies. However, in higher order multifetal gestations the uterus is extremely overdistended and the application of cerclage is equivocal. This work intended to assess the value of elective cervical sutures in prolonging triplet pregnancies. Twelve of 35 women with triplet conceptions hospitalized at our high-risk pregnancy unit underwent an elective cerclage at 12 to 14 weeks and 23 women served as control subjects. None of them had any history or physical findings of cervical incompetence prior to the procedure. The gestational age (weeks) at delivery was 33.0 +/- 5.1 and 34.7 +/- 2.8 (mean +/- SD) for the sutured and noncerclage groups, respectively. The birthweight (grams) of the neonates was 1833.0 +/- 524.5 and 1884 +/- 455.5 (mean +/- SD) for the cerclage and nonsutured women, respectively. It seems that triplet gestations as such do not benefit from an elective cervical suture.
Birth Weight↗
Discordancy in triplets.
Discordancy in twins is generally described as a weight difference between the fetuses of 15 to 25% and its prevalence in normal twin gestations is estimated at 15 to 29%. The present study was performed in order to determine the frequency of discordant newborns in uncomplicated triplet gestations. One hundred and fourteen normal triplet newborns were delivered during a period of 11 years. Their birthweight ranged from 493 to 2533 gm, with a mean of 1894.2 +/- 468.5 gm (+/- sd). In 58% of these 38 sets of triplets the difference in weight between the largest and smallest newborn was more than 15%. About a quarter of the newborns had a greater than 25% dissimilarity in their birthweights. There was no substantial fetal-fetal transfusion or difference in the Apgar scores between the discordant fetuses. It may be concluded that triplet newborns have a rate of discordancy double that of twins. Discordance per se does not necessarily mark an underlying complication of pregnancy or a bad perinatal outcome.
Birth Weight↗
Sonographic growth curves of triplet conceptions.
The diagnosis of inappropriate intrauterine fetal growth in triplet pregnancies requires normal standard sonographically determined growth curves. The aim of the present study was to establish such nomograms. The biparietal diameter (BPD), femur length, head and abdominal circumferences (HC, AC) were once in 3 weeks sonographically evaluated in 108 normal triplet fetuses. The resulting growth curves were compared with those of normal singleton fetuses. The data showed that, compared with singletons, the mean triplet fetal BPD progressively lags to a maximum of 2 1/2 weeks as pregnancy continuous from the 25th to the 36th gestational week. Similarly, mean femur length of triplet fetuses gradually shortfalls to the greatest of 2 weeks as gestation advances from the 25th to the 36th week. HC to AC ratio of the triplet fetuses does not differ from the singletons curve. It may be concluded that a normal fetal growth curve in triplet pregnancies demonstrates a 1- to 3-week delay compared with singleton gestations.
Embryonic and Fetal Development↗
The effect of growth hormone on granulosa cell function during in-vitro fertilization.
The effect of growth hormone addition to human menopausal gonadotrophin (HMG), after pituitary down-regulation, on granulosa cell function, in in-vitro fertilization (IVF) was evaluated. Growth hormone or placebo were added in a prospective, randomized and double-blind manner to an existing IVF stimulation protocol. Forty-two normal ovulatory women (< or = 38 years old) with mechanical factor infertility and normal male factor were included in the study. Gonadotrophin-releasing hormone agonist (GnRHa) was given from day 21 of the previous cycle until human chorionic gonadotrophin (HCG) administration. Follicular stimulation with HMG was started after pituitary down-regulation. Growth hormone 12 IU/day or placebo were administered on alternate days, beginning day 1 until day 7 of HMG treatment. Granulosa cell function was evaluated, in all patients, by follicular fluid levels of ovarian steroids and insulin-like growth factor-I (IGF-I). In 14 patients, chosen arbitrarily granulosa lutein cells were cultured in the presence and absence of additional HCG. Follicular fluid levels of oestradiol, progesterone, testosterone and IGF-I were similar in both growth hormone and placebo groups. Basal and post-HCG levels of oestradiol and progesterone did not differ significantly between the two groups of granulosa lutein cell cultures. We conclude that after pituitary down-regulation, in-vivo administration of growth hormone with HMG in young ovulatory women does not seem to affect granulosa cell function when compared to the administration of HMG alone.
Adult↗
Diagnosing sphingolipidoses in murine and human embryos.
The aim of this study was to diagnose lipid storage diseases in embryos at the preimplantation stage. Two parallel approaches were employed. Firstly, activities of several sphingolipid hydrolases were determined in extracts of murine embryos and also human oocytes and polyspermic embryos. Sensitive fluorescent or fluorogenic procedures provided indications that Tay-Sachs, Gaucher and Krabbe diseases might be diagnosed in one human blastomere, while for Niemann-Pick disease two might be required. Secondly, pyrene lipids were administered into murine embryos and their fluorescence was quantified by computerized imaging microscopy. As a model of Gaucher disease, the fluorescent substrate pyrene glucosylceramide was administered into murine embryos in the presence or absence of an inhibitor of the enzyme beta-glucosidase. Because of decreased degradation of the substrate in enzyme-inhibited cells, the fluorescence per blastomere was considerably greater relative to those which received no inhibitor. The results indicated that lipid storage diseases might be diagnosed in single human blastomeres at the preimplantation stage, obviating the need for pre-natal diagnosis and abortion of affected foetuses.
Animals↗
The effect of clomiphene citrate isomers on human granulosa-lutein cells in culture.
The effect of racemic clomiphene citrate and its two individual isomeric forms (i.e. en and zu) on corpus luteum function was evaluated. Granulosa-lutein cells were obtained from three normal ovulatory women undergoing oocyte retrieval following ovulation induction with agents other than clomiphene citrate for in vitro fertilization--embryo transfer (IVF-ET). The granulosa cells were cultured in the presence and absence of the three forms of clomiphene citrate, and in the presence and absence of human chorionic gonadotropin (hCG). Patients were recruited from the unit for assisted reproductive technology in a university hospital. The main outcome measured was the production of estradiol and progesterone by cultured human granulosa cells under the various conditions described above. The production of estradiol and progesterone by the cultured granulosa cells was dose-dependently reduced to a similar extent by all three forms of clomiphene citrate. The addition of hCG augmented steroidogenesis in all groups at all concentrations, but this still remained lower in all clomiphene citrate-treated groups compared to controls. The data suggest that all three types of clomiphene citrate (racemic, en, and zu) have inhibitory effects on the production of estradiol and progesterone by cultured human granulosa-lutein cells.
Adult↗
Angiotensin-I-converting enzyme and its correlation with human follicular fluid steroids.
Angiotensin-I-converting enzyme (ACE) is a peptidyl-dipeptide hydrolase which splits off the dipeptide His-Leu from the decapeptide angiotensin I and thus converts it to angiotensin II. We determined ACE activity in human preovulatory follicular fluid to further establish the intraovarian activity of the renin angiotensin system. Follicular fluids (n = 18) were obtained from eight patients undergoing in vitro fertilization (IVF) and embryo transfer (ET). ACE activity in follicular fluid and serum was determined by fluorescent spectrophotometry. The median follicular fluid ACE activity was 1.12 (range: 0.19-1.56) nmol/min/ml. This value was significantly lower than ACE activity in serum, 1.50 (range: 1.22-1.57) nmol/min/ml (P less than 0.001). In contrast to this 3:4 ratio between follicular fluid and serum ACE when expressed per ml fluid, the values were very similar when expressed per mg of protein: 0.025 vs. 0.023 nmol/min/mg in follicular fluid and serum, respectively. Correlations were sought between follicular fluid ACE activity and both serum and follicular fluid E2 and P4. A highly significant correlation (P less than 0.0005, r = 0.73) was found between ACE activity in follicular fluid and follicular fluid P4. The presence of significant ACE activity in human follicular fluid further supports the local-ovarian activity of the renin angiotensin cascade.
Embryo Transfer↗
[Oocyte donation--a method or treatment and a model for understanding the physiology of reproduction].
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Embryo Transfer↗
Enhancing in vitro fertilization of mouse oocytes by partial zona pellucida digestion.
This work was undertaken in order to evaluate the effect of partial zona digestion on fertilization in vitro of mouse oocytes and assess zona surface changes induced by the procedure. Three hundred forty-six oocytes allocated for treatment were exposed to Ham's F-10 medium supplemented with 0.5% Pronase for either 3 min (188 oocytes) or 5 min (158 oocytes); 324 oocytes served as controls. Oocyte losses incurred as a result of the procedure were small (15 oocytes; 4.3%). Control and Pronase-treated oocytes were each divided into four subgroups and inseminated with 5 x 10(5), 5 x 10(4), 5 x 10(3), or 5 x 10(2) sperm cells/ml. Fertilization was assessed 8 hr following insemination by the appearance of two pronuclei and development to the two- to four-cell stage the following day. The morphology of the zona pellucida following Pronase treatment was assessed by phase-contrast and scanning electron (SEM) microscopies performed immediately after treatment. Fertilization rate of control oocytes was 80% at a sperm concentration of 500,000/ml and gradually declined to approximately 30% at 500 cells/ml. In contrast, treated oocytes inseminated with 500 sperm cells/ml demonstrated a normal rate of fertilization. At this low sperm concentration the longer Pronase treatment was significantly (P less than 0.05) more efficient in enhancing fertilization (69 and 88% for 3 and 5 min of Pronase treatment, respectively). Polyspermic fertilization was not observed in any of the subgroups. Phase-contrast microscopic examination of oocytes at the time of Pronase treatment showed an initial swelling of the zona pellucida for 30-60 sec with a time-dependent increase in its transparency.
Animals↗
Artificial endometrial preparation for oocyte donation: the effect of estrogen stimulation on clinical outcome.
Morphologic studies of the endometrium have demonstrated that varying the duration of an artificial follicular phase (AFP) in women with ovarian failure did not adversely affect its developmental capacity. The aim of this study was to evaluate whether such manipulations of endometrial stimulation could influence the pregnancy rate in women undergoing oocyte donation (OD). Twenty-nine women were investigated in 51 cycles of OD. Endometrial preparation was performed with a fixed dose of micronized estradiol, 4 mg/day, administered for 5-35 days in accordance with oocyte availability. On the day of donation progesterone in oil, 50 mg/day, was added to the regimen. Oocytes were donated anonymously by patients undergoing routine in vitro fertilization. Fifteen clinical pregnancies were achieved, for a success rate of 29.4%. Using logistic regression analysis the success rate was found to be closely associated with the duration of estrogen stimulation. The pregnancy rate was 7.7, 52, and 7.7% after an AFP of 4-11, 12-19, and 20-29 days, respectively. It seems that for optimal results in an OD program, estrogen stimulation should be kept at between 12 and 19 days. These results also imply that, contrary to endometrial morphology, which seems to be tolerant to extreme AFP durations, functional receptivity is less permissive and is adversely affected by such manipulations.
Adult↗