W. Ian H. Johnston

A human sperm-zona pellucida binding test using oocytes that failed to fertilize in vitro

A test for human sperm binding to the zona pellucida (ZP) was developed using oocytes which failed to fertilize in vitro. Heterospermic insemination with equal numbers of test and fertile donor sperm differentially labeled with fluorescein isothiocyanate or tetra-methylrhodamine B isothiocyanate controlled for variability in ZP-sperm binding capacity. The number of sperm bound to the ZP was independent of previous sperm binding in in vitro fertilization (IVF), preservation of the ZP in salt solution, and fluorochrome labeling but increased linearly with time and sperm concentration. Sperm from men who had one or more failed attempts at IVF with no or few oocytes fertilized usually displayed very low ZP binding ratios of test to normal sperm. This test may predict the ability of sperm to fertilize human oocytes in vitro and should be useful in studies of human gamete interaction.

Analysis of the benefits and risks of multiple embryo transfer.

Depending on embryo quality and recipient factors, increasing the number of embryos transferred after in vitro fertilization may produce more pregnant patients or more multiple pregnancies. An analysis is outlined demonstrating how observations on the placement of two embryos in the uterus may be used to estimate the risks and benefits associated with the transfer of multiple embryos. Currently, the highest pregnancy rates are obtained with multiple embryo transfers, and these results are compared with the mathematical model.

The use of in vitro fertilization to evaluate putative tests of human sperm function

Results of 106 in vitro fertilization procedures were used to evaluate the usefulness of tests of human sperm function for predicting fertilization rates. Sperm tests included concentration, motility, morphology, vitality (eosin Y exclusion), nuclear immaturity (aniline blue stain), and hypo-osmotic swelling. Only the number of sperm in the insemination medium, percentage normal morphology, and vitality were statistically significant in logistic regression models of fertilization rates. The other tests, such as the hypo-osmotic swelling test, did not give additional information about fertilization rates in this study. It is concluded that logistic regression analysis of factors affecting results of fertilization in vitro provides a powerful tool for evaluating some clinical tests of sperm function.

A sperm-zona pellucida binding test and in vitro fertilization.

Sperm binding to the zona pellucida was studied in 106 in vitro fertilization (IVF) patients. Oocytes that failed to fertilize in vitro were inseminated with a mixture of equal numbers of test and fertile donor sperm differentially labeled with fluorescein or rhodamine to control for variability in the sperm-zona pellucida binding capacity of oocytes. The ratio of the number of test and control sperm bound to four to six zonae pellucidae was significantly correlated with sperm morphology, viability, motility, motility index, and normal intact acrosomes in semen. The sperm-zona pellucida binding ratio was the most significant factor related to IVF rates by logistic regression analysis. But the proportions of sperm with normal morphology and intact acrosomes in semen also were significant. In patients with

Sperm antibodies and human in vitro fertilization.

In order to directly evaluate the effects of sperm antibodies in human in vitro fertilization (IVF), the authors preincubated donor sperm in female sera containing sperm antibodies and then inseminated supernumerary human oocytes from a gamete intrafallopian transfer (GIFT) program. The sperm were incubated for 30 minutes in medium containing 20% serum with antisperm activity (Test); or no antisperm activity (Control) as assessed by the immunobead test (IBT). Each oocyte was inseminated with 1 to 2 X 10(5)/ml of the preincubated motile sperm with Control or Test treatments allocated on a random basis. Six positive sera were tested in 17 experiments, resulting in a fertilization rate of 41% (25/61) versus 84% (36/43) for controls (P less than 0.001). When considered individually, three of six positive sera caused significant inhibition. The only serum that gave complete inhibition had the highest titer for IgG (10,000) and lower IgA (100). Absorption with protein A reduced the IgG titer to less than 10 and removed the fertilization inhibitory activity. These results confirm that sperm antibodies from female sera can inhibit human IVF.

Necrospermia and chronic spinal cord injury.

OBJECTIVE To determine whether improvement in quality of semen over 4 consecutive days of electroejaculation in men with chronic spinal cord injury (SCI) was consistent with epididymal necrospermia. DESIGN Prospective study of a random sample of men with SCI. SETTING A southeastern Australian SCI management center in collaboration with the specialist andrology service of a university-based department of obstetrics and gynecology in a tertiary referral hospital. PATIENT(S) Nine men with chronic spinal cord injury. INTERVENTION(S) Semen samples were obtained by using electroejaculation, and testicular biopsy samples were obtained by using fine-needle tissue aspiration. MAIN OUTCOME MEASURE(S) Semen analysis was performed according to World Health Organization criteria. Testicular biopsy and electron microscopy were done by using standard techniques. RESULT(S) During up to 4 days of consecutive-day electroejaculation, sperm motility and viability in semen obtained from men with chronic SCI increased by an average of 23% on days 2 and 3. The severity of the degenerative changes and the numbers of spermatozoa affected on day 1 became less marked by day 4. The changes were not present in late spermatids obtained from testicular biopsies. CONCLUSION(S) The asthenospermia of chronic SCI is similar to epididymal necrospermia and can be improved by consecutive-day electroejaculation.

Effect of sperm antibodies in females on human in vitro fertilization

The effect of sperm antibodies derived from the female partners serum on fertilization and embryo cleavage was evaluated by analyzing the Royal Womens Hospital in vitro fertilization (IVF) data. The results suggest that antispermatozoal isoantibodies detected by the immunobead test (IBT) can interfere with IVF. Thus, in a group of patients with IBT-IgG and IBT-IgA sperm antibody titers of greater than or equal to 10 in serum, a low fertilization rate (15%) was obtained when the wifes serum was used as serum supplement in the IVF culture medium. Where replacement (antibody-negative donor or cord) serum was used in the culture medium, a higher fertilization rate (69%) was obtained (P less than 0.01). These results underline the importance of using replacement serum in cases where the wife has significant sperm antibody levels in her serum. Six pregnancies were obtained in the antibody-positive group (n = 20), five of which occurred in patients with IBT-IgG and IBT-IgA-titers less than 10, for a pregnancy rate of 5/9 in this subgroup. Four of these patients delivered (4/9). Analysis of larger groups of antibody-positive patients is required for further evaluation of these results and ascertainment of the likelihood of occurrence of posttransfer effects of sperm antibodies on the embryo.

Prediction of outcome in human in vitro fertilization based on follicular and stimulation response variables

Since in vitro fertilization (IVF) pregnancy rates have reached a plateau in recent years, there is need for a system of assessment, which could provide a guide for improvements. The follicular characteristics, the response to stimulation, the quality of sperm used for insemination, and the embryonic human chorionic gonadotropin production of 222 women who had undergone routine IVF treatment have been analyzed. Models, predictive of IVF outcome, have been developed using these parameters in various combinations. The results have shown that follicular health and maturity are critical to IVF outcome and that certain patterns of response to ovarian stimulation are associated with the more frequent occurrence of oocytes capable of normal embryonic development after fertilization.

Midcycle changes of 17-OH-progesterone levels in women superovulated with clomiphene citrate and human menopausal gonadotropin for in vitro fertilization*

The dynamics of 17-alpha-hydroxy-progesterone (17-OHP) production during the onset of the luteinizing hormone (LH) surge were evaluated at 8-hour intervals and correlated with plasma estradiol (E2), LH, and progesterone (P) in 22 women superovulated for in vitro fertilization. Plasma 17-OHP levels rose 8 to 16 hours before the earliest rise in LH and P in 18% of patients, but had risen significantly in 82% of patients by the onset of the LH surge. In the late follicular phase, 17-OHP levels correlated significantly with E2 and LH levels, and the number of follicles greater than 10 mm. Because rising 17-OHP levels preceded the LH surge in only a few patients, it has no clinical value as a marker for human chorionic gonadotropin administration for timed oocyte recovery. Plasma 17-OHP levels, however, may complement LH levels better than P levels in determining the most appropriate stage for surge-timed oocyte retrieval.