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Biomedical subjects

S Oehninger

Publications and source records attributed to S Oehninger.

At least 163 records · Page 9Linked to original sources
PubMed1988

Corrective measures and pregnancy outcome in in vitro fertilization in patients with severe sperm morphology abnormalities.

Sperm morphology evaluated by new, strict criteria is a good predictor of outcome in in vitro fertilization (IVF). This study aimed (1) to determine whether the fertilization rate of preovulatory oocytes in patients with abnormal morphology can be improved by increasing insemination concentration at the time of IVF and (2) to evaluate the pregnancy outcome in patients with abnormal sperm morphology. Three groups were studied: (1) normal morphology, (2) good prognosis pattern, and (3) poor prognosis pattern. All other sperm parameters were normal. Group 3 had a lower overall fertilization rate, lower pregnancy rate/cycle, and lower ongoing pregnancy rate/cycle. Groups 2 and 3 showed a higher miscarriage rate, although not significantly different from group 1. By increasing insemination concentration from 2- to 10-fold, the fertilization rate in group 3 increased from 14.5% to 62.6%. However, pregnancy outcome did not improve. We conclude that patients with severe sperm head abnormalities have a lower ability to establish successful pregnancies, even though fertilization may be achieved.

Abortion, Spontaneous↗
PubMed1988

The value of basal and/or stimulated serum gonadotropin levels in prediction of stimulation response and in vitro fertilization outcome.

The purpose of this study was to determine whether basal or stimulated (or both) serum follicle-stimulating hormone (FSH) and luteinizing hormone (LH) on day 3 of the cycle before administration of exogenous gonadotropins can predict stimulation response and in vitro fertilization (IVF) outcome. Eighty consecutive new patients underwent a gonadotropin-releasing hormone (GnRH) stimulation test on the morning of cycle day 3. All patients underwent the same stimulation protocol consisting of a combination of FSH and human menopausal gonadotropin (hMG). Paired discriminant analysis of FSH0 (at 0 minutes from GnRH injection) and LH0 revealed seven distinct groups of patients with statistically significant differences among the means: groups 1, 2, and 3 (26.25%) with higher means FSH0:LH0; group 4 (40%) with mean FSH0:LH0 (both levels less than 10 mIU/ml) of 1:1, and groups 5, 6, and 7 (33.75%) with higher mean LH0:FSH0. Canonical discriminant analysis of both basal and stimulated serum FSH and LH levels confirmed the seven groups and did not add to the information from analysis of FSH0 and LH0 only. Serum estradiol (E2) response during stimulation, as well as the number of preovulatory oocytes aspirated and transferred, was highest in the groups with a higher mean LH0:FSH0, intermediate in the group with mean FSH0:LH0 of 1:1, and lowest in the group with a higher mean FSH0:LH0. No pregnancy occurred in the higher FSH:LH groups. It is concluded that basal serum gonadotropin levels can distinguish different populations of IVF patients who tend to behave differently in terms of E2 response, oocytes obtained and transferred, and pregnancy rates and outcome.

Abortion, Spontaneous↗
PubMed1988

Implantation potential of each pre-embryo in multiple pregnancies obtained by in vitro fertilization seems to be different.

Endometrial receptivity and pre-embryo quality are the main factors determining embryo implantation in in vitro fertilization. If one embryo implants normally and goes to term, the endometrium can be assumed to be normal. Eighty-one patients (March 1981 to 1987) had transfers of multiple pre-embryos, resulting in multiple pregnancies with at least one reaching term. The number of gestational sacs at 8 to 12 weeks of pregnancy, at 20 weeks, and the number of term pregnancies were studied longitudinally. Twelve patients (14.8%) had 2 pre-embryos transferred, 19 (23.5%) had 3, 21 (25.9%) had 4, 17 (21.0%) had 5, 9 (11.1%) had 6, and 3 (3.7%) had 7. At 20 weeks 18 patients (22.2%) had a single viable fetus, 56 (69.1%) had twins, 6 (7.4%) had triplets, and 1 (1.2%) had quadruplets. A total of 325 pre-embryos were transferred; 178 gestational sacs were observed at 8 to 12 weeks, but only 153 showed fetal heartbeat. Total embryo loss at 8 to 12 weeks was 53.0%; when the "index" embryo was excluded, it reached 61%. Regardless of the number of pre-embryos transferred, only 2.2 embryos on average were able to establish a normal pregnancy. (A)synchronism of the pre-embryos did not affect outcome. Results suggest that with normal endometrial receptivity, the implantation potential of each pre-embryo is different.

Embryo Transfer↗
PubMed1988

Correlation between sperm morphology, acrosin, and fertilization in an IVF program.

Acrosin, a neutral proteinase, is located within the acrosome. The aim of this study was to evaluate acrosin concentrations in patients with severe damage of the sperm head and to determine whether acrosin concentration could predict the chances of fertilization in an IVF program. Sixty patients were accepted into this study, prospectively. The patients were divided into two groups, those with a normal morphology of less than 14% (group I, n = 33) and those with normal morphology less than 14% (group II, n = 27). All patients had a sperm concentration of less than 20 million sperm/ml and less than 30% progressively motile sperm. The acrosin assays were performed on the semen sample obtained on the day of IVF. Routine IVF insemination procedures were used, and only mature oocytes were considered. The only factor that showed a significant correlation of fertilization was normal morphology (p less that 0.01). The mean acrosin level was 73.4 /+- 38.6 mED/10 million sperm in group I and 70.9 /+- 42.7 mIU/10 million sperm in group II (no significant difference). The fertilization rate in group I was 45.4% and in group II, 77.7% p less than 0.002). Acrosin levels were not significantly different in patients with and without fertilization (72.0 /+- 42.1 and 73.6 /+- mIU/10 million sperm, respectively).

Acrosin↗
PubMed1988

Abdominal pregnancy after in vitro fertilization and embryo transfer.

Ectopic pregnancy continues to be a major complication of in vitro fertilization (IVF) and embryo transfer. We report the first abdominal pregnancy occurring after this therapeutic approach. The patient, a 35-year-old female, presented a frozen pelvis with a history of severe endometriosis and a left salpingectomy. After the transfer of four concepti in her second IVF/embryo transfer attempt, she became pregnant. Unfortunately, ultrasound evaluation five weeks later showed an ectopic pregnancy in the cul-de-sac. During laparotomy, it was noticed that implantation had taken place near the mesentery of the sigmoid and rectosigmoid. A right cornual tubal ligation was performed. Although the benefit of IVF/embryo transfer far outweighs the risk of an ectopic pregnancy, it is imperative that physicians who care for patients after IVF/embryo transfer be fully aware of the possibility of this complication in this high-risk population.

Adult↗
PubMedDate not supplied

Sperm function assays and their predictive value for fertilization outcome in IVF therapy: a meta-analysis.

The prevalence of male infertility and the availability of new, highly successful therapeutic options make the testing of sperm functional competence mandatory. An objective, outcome-based examination of the validity of the currently available assays was performed based upon the results obtained from 2906 subjects evaluated in 34 prospectively designed, controlled studies. The aim was carried out through a meta-analytical approach that examined the predictive value of four categories of sperm functional assays: computer-aided sperm motion analysis (CASA); induced-acrosome reaction testing; sperm penetration assay (SPA); and sperm-zona pellucida binding assays for IVF outcome. Results demonstrated a high predictive power of the sperm-zona pellucida binding and the induced-acrosome reaction assays for fertilization outcome. On the other hand, the findings indicated a poor clinical value of the SPA as predictor of fertilization and a real need for standardization and further investigation of the potential clinical utility of CASA systems. This analysis points out to limitations of the current tests and the need for standardization of methodologies and provides objective evidence on which clinical management and future research can be based.

Acrosome Reaction↗
PubMedDate not supplied

Hemizona assay and its impact on the identification and treatment of human sperm dysfunctions.

The HZA, a functional test for human gamete interaction, has become a useful and valuable experimental tool for physiological and cellular analysis of the early events leading to fertilization. The analysis of the conventional semen parameters with emphasis on sperm morphology (as judged by strict criteria) and motion characteristics (evaluated by computer assisted analysis) constitutes the first obligatory step for a critical evaluation of male-factor patients. Patients in whom fertilization disorders are suspected should be evaluated through bioassays of sperm function of established accuracy. The HZA, a bioassay of sperm-zona binding capacity is here proven to be highly predictive of IVF outcome. Ultimately, our increasing knowledge of sperm biology and dysfunction will provide a basis for a better diagnosis (membrane receptor defects and metabolic/biochemical abnormalities?) as well as better therapeutic interventions in patients with sperm disorders. It seems likely that the HZA may be eventually replaced by a standardized test kit in which recombinant human DNA-derived zona receptors mimic the natural function of the hemizonae currently used. This ZP3 reagent may also be a useful antigen for contraceptive development. The HZA therefore constitutes a useful adjuvant in the armentarium for the diagnosis and therapy of male-factor patients.

Contraception↗
PubMedDate not supplied

The relationship between morphology, motility and zona pellucida binding potential of human spermatozoa.

Prediction of the fertilizing potential of human gametes under in vitro conditions has been a major field of interest of assisted reproductive programmes. However, sperm morphology has been regarded as a predictor of human in vitro fertilization rate. This paper prospectively evaluates the relationships among normal sperm morphology and (1) motion characteristics viz. curvilinear velocity (VCL), straight line velocity (VSL), and linearity (LIN) (n = 37) and (2) sperm-zona pellucida binding capacity under HZA conditions (n = 144) of two separate groups of infertile couples. Semen was evaluated for sperm concentration, percentage motility, forward progression, and percentage normal morphology (strict criteria). The motility characteristics were measured using a computerized Sperm Motility Quantifier (SMQ). The zona binding potential of sperm was evaluated using the hemizona assay. Firstly, the VCL significantly differed between the P-pattern and both the G (72.9 +/- 7 vs. 86.3 +/- 16 microns s-1; P = 0.04) and N patterns (72.9 +/- 7 vs. 91.0 +/- 15 microns s-1; P = 0.002). The VSL differed only between the P and N patterns, being 19.7 +/- 7 vs. 32.6 +/- 15 microns s-1 (P = 0.02), respectively. No significant differences in LIN were noted between any of the three patterns. The sperm concentration differed significantly between the P and both the G (37.9 +/- 35 vs. 80.8 +/- 9 x 10(6) ml-1; P = 0.03) and the N patterns (37.9 +/- 35 vs. 89.7 +/- 72 x 10(6) ml-1; P = 0.05).(ABSTRACT TRUNCATED AT 250 WORDS)

Female↗
PubMedDate not supplied

Value of sperm morphology assessed by strict criteria for prediction of the outcome of artificial (intrauterine) insemination.

The purpose of this study was to investigate the relationship between sperm parameters and the outcome of artificial (intrauterine) insemination (IUI). One hundred and twenty-six patients undergoing 395 consecutive IUI cycles in a 1-year period in our institution were studied. In all cases, controlled ovarian stimulation and hCG-timed IUI were performed, followed by progesterone supplementation of the luteal phase. In 86 patients, (243 cycles) the husband's sperm was utilized, whereas in 40 couples (152 cycles), donor sperm was used due to severe male factor infertility. Among the sperm parameters of the original ejaculate, % normal morphology (assessed by strict criteria) was the most significant predictor of pregnancy (stepwise regression analysis, P = 0.003). Using logistic regression, morphology was the best predictor of pregnancy (r = 0.12); linearity of movement significantly enhanced the predictive value of morphology alone (r = 0.17, P = 0.004). Overall, the pregnancy rates were significantly higher (P = 0.01) in cases with > or = 14% normal morphology (15% per cycle) compared to cases with < 14% normal morphology (7% per cycle). This threshold level for morphology is in agreement with previously published IVF results. These results underscore the significance of sperm morphology assessed by strict criteria as a predictor of pregnancy outcome in the IUI setting.

Adult↗
PubMedDate not supplied

Strict criteria for the evaluation of human sperm morphology and its impact on assisted reproduction.

Sperm morphology abnormalities can be identified in a large proportion of patients with failed and delayed fertilization when assessing this parameter with strict criteria. Statistical analyses of a large IVF population confirm that, in patients with severe teratozoospermia, fertilization rates can be enhanced in many cases by increasing insemination concentration. However, implantation rates are impaired, thereby affecting the ability of these patients to establish a viable pregnancy. Data from couples undergoing controlled ovarian stimulation/intrauterine insemination seem to support the use of strict morphology as a predictor of outcome in this setting, too. Although a descriptive parameter, sperm morphology assessed by strict criteria can be used as a biomarker of sperm dysfunction(s). These dysfunctions are multiple and include abnormalities of motion parameters, poorer capacity to bind to homologous zona pellucidae and penetrate zona-free eggs, and low incidence of spontaneous and induced acrosome reaction. At a cellular level, poor morphology is associated with a higher content of creatine kinase and impaired capacity to undergo appropriate changes in intracellular calcium concentration. Whether nuclear/DNA abnormalities are present still remains to be fully determined. A definitively objective evaluation of morphology based on these criteria may allow all centres specializing in assisted reproduction to analyse semen in a homogeneous fashion.

Female↗
PubMedDate not supplied

The outcome of clinical pregnancies following intracytoplasmic sperm injection is not affected by semen quality.

The objective of this study was to investigate the impact of severe oligoasthenoteratozoospermia (OAT) on pregnancy outcome. For this purpose 279 consecutive intracytoplasmic sperm injection (i.c.s.i) cycles were retrospectively evaluated and compared to 436 consecutive IVF cycles performed during the same time frame. Group A (n = 62) included ICSI patients with severe OAT; group B (n = 217) included patients who underwent ICSI for other indications; and group C (n = 436) included couples who underwent standard IVF. The mean age of female patients and mean number of embryos transferred were comparable in all groups. No difference was observed regarding implantation, clinical pregnancy, delivery and miscarriage rates between all three groups, but fertilization rate was significantly lower in group A than in groups B and C. It is concluded that couples undergoing ICSI with severe male infertility (OAT) have a slightly reduced fertilization rate but their chances of delivery and pregnancy loss are similar to those of other patients undergoing clinical ICSI and IVF with non-male infertility.

Abortion, Spontaneous↗
PubMedDate not supplied

Involvement of selectin-like carbohydrate binding specificity in human gamete interaction.

The recognition of carbohydrate epitopes by complimentary protein receptors has been shown to be a critical factor in gamete interaction in many different animal species. In this study it was hypothesized that, in the human, gamete binding requires an interaction between selectin ligands on the zona pellucida and putative egg binding proteins on the sperm surface. The hemizona assay (a unique internally controlled bioassay that evaluates tight binding of sperm to the zona) and advanced methods of carbohydrate analysis were used to test this hypothesis. From these tests it was shown that oligosaccharide recognition is also required for initial human gamete binding. This study suggests the existence of distinct egg binding proteins on human sperm that can bind to selectin ligands. Additionally, the results suggest a possible convergence in the types of carbohydrate sequences recognized during initial human gamete binding and immune/inflammatory cell interactions. Glycoconjugates that manifest selectin-ligand activity and that express specific carbohydrate epitopes have potent contraceptive and immunosuppressive effects. Such specific oligosaccharide sequences may provide an appropriate recognition signal for embryo development and protection.

Carbohydrate Metabolism↗
PubMedDate not supplied

Immunological identification of zona pellucida 2 (ZP2) protein in human oocytes.

The ZP2 protein is a zona pellucida glycoprotein that plays a major role in fertilization. It mediates secondary binding of spermatozoa and is one of the proteins that are involved in zona 'hardening'. ZP2 proteins were identified in various mammalian zonae pellucidae. Their primary structures are highly conserved as revealed by cDNA cloning. Antisera were used against synthetic peptides generated either against a ZP2 amino acid that is homologous in human and mouse ZP2 amino acid sequences (AS ZP2-20) or antibodies against a synthetic human ZP2 peptide (AS ZP2-26). Immunoblots showed that antiserum AS ZP2-20 and AS ZP2-26 strongly recognized human ZP2 protein with an apparent molecular mass of about 72 kDa; both antisera reacted with a minor immunoreactive polypeptide at 96 kDa. In human ovary sections, both antisera revealed immunoreactivity to human zonae pellucidae. Immuno-electron microscopy demonstrated an equal distribution of ZP2 throughout the human zona pellucida. Considerable amounts of immunoreactive material were observed in the ooplasm; some ramification-like extensions of zona pellucida antigen were found close to cells surrounding the oocyte. Our results indicate that antisera against synthetic ZP2 peptides can be used as specific markers for the identification of ZP2 protein in human oocytes.

Animals↗
PubMedDate not supplied

Does endothelin-1 affect human spermatozoa function?

PROBLEM: It has been reported that massive amounts of immunoreactive endothelins (ETs) exist in human seminal plasma. However, the physiological role of ETs in seminal plasma remains to be determined. We speculated that ETs might affect sperm function. METHOD: The present study was designed to investigate the effect of endothelium-1 (ET-1) on: (a) sperm motion parameters, (b) hyperactivated motility, (c) sperm-zona pellucida-binding capacity, (d) sperm-oocyte penetration capacity, (e) acrosome reaction and its prerequisite, an increase in intracellular Ca2+ concentration ([Ca2+]i), and to examine (f) the presence of binding sites for ET-1 in human sperm. Forty-six semen ejaculates from 14 fertile men were assessed under capacitating conditions after separation of the motile sperm fraction by wash and swim-up. RESULTS: ET-1 (1 micron) exhibited significant stimulatory effects on sperm velocity at 30 min (P = 0.01), amplitude of lateral head displacement (ALH)max (P = 0.05), and ALHmean at 60 min (P = 0.04) in some samples (n = 10). However, these effects were not observed in experiments using a larger number of samples (n = 39). ET-1 had no effect on hyperactivated motility of sperm at 30 min to 24 h. Neither ET-3 nor IRL 1620, a selective ETB receptor agonist, affected sperm motion parameters or hyperactivated motility. ET-1 did not affect sperm-zona-binding capacity, sperm-oocyte penetration capacity, acrosome reaction, or [Ca2+]i of sperm. Specific binding sites for ET-1 were not detected on the cell surface of human sperm. CONCLUSIONS: Although ET-1 is present in massive amounts in human seminal plasma and may have the capacity to alter the quality of motile sperm in some samples, a physiological role of ET-1 in the modulation of the function of mature, ejaculated sperm still remains unknown.

Acrosome↗
PubMedDate not supplied

Penetration of human spermatozoa through the zona pellucida of nonviable human oocytes.

OBJECTIVE: The purpose of this study was to evaluate the penetrating capacity of human sperm through the intact zonae of nonviable human oocytes and the influence of oocyte storage conditions and gamete coincubation times on penetration rates. METHODS: Immature oocytes were obtained from surgically removed ovarian tissue and from in vitro fertilization (IVF) and subjected to four storage conditions: 1) storage at 4 degrees C for up to 48 hours in culture medium (refrigeration, n = 53), 2) cryopreservation in 1.5 mol/L propanediol with storage at -196 degrees C (PrOH; n = 49), 3) cryopreservation in 2.0 mol/L dimethylsulfoxide with storage at -70 degrees C (DMSO; n = 20), and 4) storage in a hypertonic salt solution at 4 degrees C (salt; n = 30). Semen was obtained from fertile donors (n = 7) and after a wash and swim-up, samples were adjusted to 500,000 motile sperm/mL. Zonae and sperm were coincubated in 100-microL drops under oil, and penetration was assessed at 5 and 20 hours. Penetration was evidenced by visualization of at least one sperm head in the perivitelline space at 200x magnification. RESULTS: Zona penetration rates were 50.9, 32.7, 23.3, and 10.0% for refrigeration, PrOH, salt, and DMSO storage, respectively (P < .004). There was a significantly higher number of sperm in the perivitelline space after 20 hours' coincubation (3.8 +/- 0.2) compared to 5 hours (0.8 +/- 0.1) (P < .0006). This represented an increase in the penetration rate from 31.2% (34 of 109) at 5 hours to 37.6% (41 of 109) at 20 hours, although the difference was not significant. CONCLUSIONS: These results demonstrate that the zona pellucida of nonviable human oocytes can be used in a zona penetration assay and that refrigerated and PrOH-frozen intact zonae have the highest rates of penetration. The decrease in penetrability seen in DMSO and salt-stored oocytes may be due to alterations occurring in the zona pellucida.

Cell Survival↗
PubMedDate not supplied

Enhancement of in vitro murine embryo development by recombinant leukemia inhibitory factor.

OBJECTIVE: Human recombinant leukemia inhibitory factor (rLIF) has been shown to stimulate hatching of murine and ovine embryos in vitro. The temporal and dose-dependent effects of murine rLIF (mrLIF) and human rLIF (hrLIF) on embryo development in two different mouse strains were investigated in this work. METHODS: Two-cell embryos were recovered from the fallopian tubes of superovulated/mated females and cultured in Krebs medium plus bovine serum albumin in microdroplets under oil. RESULTS: In the B6CBF1 strain, mrLIF significantly stimulated blastocyst formation and decreased embryo fragmentation/degeneration when added simultaneously at the initiation of culture or 24 hours thereafter. Human rLIF also had a positive effect on development. In the CD1 strain (lower fecundity), mrLIF dose-dependent effects were observed, with enhanced developmental stimulation achieved with higher doses. CONCLUSIONS: These findings confirm that hrLIF stimulates mouse embryo development in vitro and that different mouse strains show distinct responses to the cytokine. In addition, mrLIF enhances blastocyst formation and decreases embryo fragmentation when added to the embryo culture as early as the two-cell stage.

Animals↗
PubMedDate not supplied

Therapeutic intrauterine insemination improves with gonadotropin ovarian stimulation.

Therapeutic intrauterine insemination (IUI) is frequently used as a first line of treatment of infertility. The reported results vary, depending on the indication and the use of ovulation simulation protocols. In the present study, we review the experience at the Jones Institute for Reproductive Medicine in Virginia from January 1989 to January 1991. The patients were preferentially treated with ovulation induction with gonadotropins. With the addition of gonadotropin stimulation, the total and term pregnancy rates per cycle were 14% and 11%, respectively, including all etiologic factors. These rates were improved over the 3% and 2.6% rates reported in our previous study in which ovarian stimulation was not generally used. In male factor patients, the term pregnancy rate was 9%, higher than the 4% term pregnancy rate reported in our previous study. In the present series, morphology was the only severely impaired parameter. The term pregnancy rate was 11% for patients with ovulatory dysfunction, 10% for those with cervical factor, and 10.5% for those with unexplained infertility.

Adult↗