Sergio Oehninger

Predictive value of abnormal sperm morphology in in vitro fertilization.

In patients with acceptable sperm count and motility, two patterns of abnormal morphology, judged with strict criteria, were identified and described. Patients with less than 4% normal forms and less than 30% morphology index (summation of normal and slightly amorphous forms) had a fertilization rate of 7.6% of the oocytes (P pattern, poor prognosis). Patients with normal morphology between 4 and 14% had a significantly better fertilization rate of 63.9% of the oocytes (P less than 0.0001). Cases with greater than 14% normal forms fertilized within the normal range for the laboratory. By evaluating sperm morphology with the proposed strict criteria, its predictive value in in vitro fertilization is enhanced.

Follicle-stimulating hormone levels on cycle day 3 are predictive of in vitro fertilization outcome

Cycle day 3 basal levels of follicle-stimulating hormone (FSH), luteinizing hormone (LH), and estradiol (E2) were measured in 441 patients in 758 consecutive cycles to determine their predictive value for stimulation quality and pregnancy rates in vitro fertilization (IVF). Patients with low basal FSH levels (less than 15 mIU/ml) had higher pregnancy rates per attempt than those with moderate levels (15 to 24.9 mIU/ml), both of which were higher than those with high FSH levels (greater than 25 mIU/ml). Basal LH and E2 values did not improve the predictive value beyond that provided by FSH. Ongoing pregnancy rates per attempt in the low, moderate, and high FSH groups were 17.0%, 9.3%, and 3.6%, respectively (P less than 0.01). The three groups differed significantly in the percentage of patients having two ovaries, the mean number of follicles aspirated per retrieval, the mean number of preovulatory oocytes obtained, and peak E2 values (P less than 0.01). Cycle day 3 FSH levels are predictive of pregnancy outcome and stimulation characteristics in IVF, and may be useful in counseling patients.

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.

Structural Analysis of the Oligosaccharides Derived from Glycodelin, a Human Glycoprotein with Potent Immunosuppressive and Contraceptive Activities

Glycodelin, also known as placental protein 14 (PP14) or progesterone-associated endometrial protein (PAEP), is a human glycoprotein with potent immunosuppressive and contraceptive activities. In this paper we report the first characterization of glycodelin-derived oligosaccharides. Using strategies based upon fast atom bombardment and electrospray mass spectrometry we have established that glycodelin is glycosylated at Asn-28 and Asn-63. The Asn-28 site carries high mannose, hybrid and complex-type structures, whereas the second site is exclusively occupied by complex-type glycans. The major non-reducing epitopes in the complex-type glycans are: Galβ1-4GlcNAc (lacNAc), GalNAcβ1-4GlcNAc (lacdiNAc), NeuAcα2-6Galβ1-4GlcNAc (sialylated lacNAc), NeuAcα2-6GalNAcβ1-4GlcNAc (sialylated lacdiNAc), Galβ1-4(Fucα1-3)GlcNAc (Lewis), and GalNAcβ1-4(Fucα1-3)GlcNAc (lacdiNAc analogue of Lewis). It is possible that the oligosaccharides bearing sialylated lacNAc or lacdiNAc antennae may manifest immunosuppressive effects by specifically blocking adhesive and activation-related events mediated by CD22, the human B cell associated receptor. Oligosaccharides with fucosylated lacdiNAc antennae have previously been shown to potently block selectin-mediated adhesions and may perform the same function in glycodelin. The potent inhibitory effect of glycodelin on initial human sperm-zona pellucida binding is consistent with our previous suggestion that this cell adhesion event requires a selectin-like adhesion process. This result also raises the possibility that a convergence between immune and gamete recognition processes may have occurred in the types of carbohydrate ligands recognized in the human.

Effects of hydrogen peroxide on DNA and plasma membrane integrity of human spermatozoa

OBJECTIVE To evaluate the effects of oxidative stress on DNA and plasma membrane integrity of human spermatozoa. DESIGN Prospective cohort study. SETTING University-based, tertiary-care infertility center. PATIENT(S) Men (n = 10) undergoing infertility investigation. INTERVENTION(S) Purified populations of sperm with high motility were separated using Percoll density gradients. Then, spermatozoa were incubated with 0, 10, 100, and 200 microM hydrogen peroxide (H(2)O(2)) under capacitating conditions. MAIN OUTCOME MEASURE(S) Motion parameters were assessed by computer analysis. Genomic integrity was examined by the terminal deoxynucleotidyl transferase (TdT)-mediated dUTP nick end-labeling (TUNEL) assay. Plasma membrane integrity was evaluated by the annexin V-binding assay, a measure of phosphatidylserine translocation. RESULT(S) Under basal conditions, there was a significant and negative relationship between sperm motility and the percentages of sperm with DNA fragmentation and membrane translocation of phosphatidylserine. After a 2-h incubation, there was a significant, dose-dependent effect of H(2)O(2) on motion parameters (decrease) and DNA fragmentation (increase). The percentage of annexin V(-) live (normal) cells declined significantly as the level of oxidative stress increased. Although the percentages of annexin V(+) live cells (sperm depicting translocation of phosphatidylserine) and necrotic cells increased at the highest H(2)O(2) levels, these changes were not significant. CONCLUSION(S) In vitro sperm incubation with H(2)O(2) induces DNA fragmentation in a dose-dependent fashion. The sublethal effects of oxidative stress on motion parameters were not significantly associated with membrane translocation of phosphatidylserine.

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.

INTERCYCLE VARIABILITY OF DAY 3 FOLLICLE-STIMULATING HORMONE LEVELS AND ITS EFFECT ON STIMULATION QUALITY IN IN VITRO FERTILIZATION

Prior studies have demonstrated that gonadotropin stimulation quality and pregnancy rates are better in in vitro fertilization (IVF) patients with low basal cycle day 3 follicle-stimulating hormone (FSH) levels. The records of 81 patients who had undergone three or more IVF attempts during a 2-year period were studied to determine the degree and potential impact of intercycle variability in basal FSH concentrations. The mean of the individual standard deviations for all 81 patients was 4.2 +/- 0.4 mIU/mL. However, the patients with a mean basal FSH of less than 15 mIU/mL had a mean deviation of only 2.6 +/- 0.2 mIU/mL, whereas those with a mean basal FSH of greater than or equal to 15 mIU/mL had a mean deviation of 7.3 +/- 0.7 mIU/mL. Intercycle variability in basal FSH values did not predict changes in ovarian response to gonadotropin stimulation and thus may not be used to select an optimal cycle in which to stimulate an individual patient. Furthermore, patients with large intercycle variation responded poorly to gonadotropin stimulation independent of their basal FSH concentration. This information allows more precise counseling of patients regarding their appropriateness for assisted reproduction.

Factors affecting fertilization: endometrial placental protein 14 reduces the capacity of human spermatozoa to bind to the human zona pellucida*†

OBJECTIVE To examine whether placental protein 14 (PP14) may affect directly those sperm functions crucial to fertilization and early embryo development. DESIGN In these prospective studies, we evaluated semen samples of fertile men incubated under capacitating conditions with and without PP14. SETTING Academic tertiary institution. INTERVENTIONS Biologically active PP14 was purified from human midtrimester amniotic fluid by anion exchange and immunoaffinity chromatography. After separation of the motile fraction, spermatozoa were incubated for 30 minutes with or without PP14 (concentration range of 0.01 to 100 micrograms/mL), washed, and then aliquots were prepared for use in the different assays. Human sperm-zona pellucida (ZP) binding was assessed using the hemizona assay (HZA) in a 4-hour gametes coincubation period. Sperm motility parameters were evaluated using a computerized semen analyzer. The acrosome reaction (AR) was determined by fluorescein isothiocyanate-conjugated Pisum sativum agglutinin and indirect immunofluorescence. MAIN OUTCOME MEASURES Sperm-ZP binding, sperm motility patterns, and AR. RESULTS Preincubation of sperm (and not the hemizonae) with PP14 produced a significant and dose-dependent inhibition of binding in the HZA. Monoclonal antibodies generated against PP14 showed no direct effect in the HZA and partially neutralized the inhibitory activity of PP14 in the HZA. Insulin-like growth factor binding protein-1 (IGFBP-1), an endometrial stromal cell product, showed no effect in the HZA. Neither PP14 nor IGFBP-1 interfered with sperm motility parameters or the AR. CONCLUSIONS Placental protein 14 produced a potent, fast, and dose-dependent inhibition of binding of human spermatozoa to the human ZP without affecting other prefertilization events (i.e., hyperactivated motility or AR). The detrimental effect on sperm-zona interaction seems to be specific for this endometrial epithelial protein (not observed with an endometrial stromal product) and may have fundamental bearance to the fertilization process thus providing a mechanism for endometriosis-related infertility.

Sperm morphology as diagnosed by strict criteria: probing the impact of teratozoospermia on fertilization rate and pregnancy outcome in a large in vitro fertilization population

OBJECTIVE To investigate the predictive value of sperm morphology assessed by strict criteria on IVF outcome. DESIGN Retrospective analysis of all IVF cycles (January 1987 to December 1992). MAIN OUTCOME MEASURES All patients were assigned to one of three groups based on sperm morphology: P-pattern (< 4% normal forms), G-pattern (4% to 14% normal forms), and N-pattern (> 14% normal forms). Morphology pattern was related to other semen characteristics and IVF outcome. RESULTS Despite corrective measures at oocyte insemination, the fertilization rate was significantly different among the three morphology groups, P < G < N. N-pattern sperm produced a mean fertilization rate over 85% regardless of low motility or concentration. In a cohort study, P-pattern cycles produced a lower implantation rate and lower ongoing pregnancy rate, independent of the lower fertilization rate. CONCLUSIONS Strict morphology is an excellent biomarker of sperm fertilizing capacity, independent of motility and concentration. P-pattern sperm may denote a poorer prognosis for establishing a pregnancy, even after a satisfactory fertilization rate is achieved.

Gender-specific Glycosylation of Human Glycodelin Affects Its Contraceptive Activity

We have recently demonstrated that a human amniotic fluid-derived glycoprotein, glycodelin-A (GdA; previously known as PP14 or PAEP), potently inhibits gamete binding in an established sperm-egg binding system and expresses immunosuppressive activities directed against a variety of different immune cell types. GdA has high mannose-, hybrid-, and complex-type biantennary oligosaccharides including structures with fucosylated or sialylated N,N′-diacetyllactosediamine (GalNAcβ1-4GlcNAc) sequences, which are rare in other human glycoproteins. We now report the characterization of glycodelin-S (GdS). This is a human seminal plasma glycoprotein that is immunologically indistinguishable from GdA, but unlike the latter, does not inhibit human sperm-zona pellucida binding under hemizona assay conditions. Analysis of the N-glycans of GdS by mass spectrometry revealed that all glycoforms of GdS are different from those of GdA. GdS glycans are unusually fucose-rich, and the major complex-type structures are biantennary glycans with Lewisx (Galβ1-4(Fucα1-3)GlcNAc) and Lewisy (Fucα1-2Galβ1-4(Fucα1-3)GlcNAc) antennae. It is probable that these highly fucosylated epitopes contribute to the immunosuppressive activity of human seminal plasma and to the low immunogenicity of sperm. This study provides the first evidence for gender-specific glycosylation that may serve to regulate key processes involved in human reproduction.