H.W.G. Baker

Contraceptive efficacy of testosterone-induced azoospermia in normal men

0.6). a higher mean of maximal serum 17-estradiol levels (560 versus I78 pg/mL). a shorter duration of menotropin treatment (7 versus I I days). and fewer ampules of monotropin used (20 versus 37 ampules/cycle) in metoclopramide-treated cycles as compared with control cycles, respectively. Serum prolactin levels reached a maximum of 172 ng/mL within I h after metoclopramide administration and declined to normal range within 6 h. These results suggest that intermittent increased prolactin secretion may augment ovarian response to gonadotropins.

Immunoinfertility: A Case Study with Implications for Immunocontraception

A detailed case history was compiled on a couple who have had primary infertility for more than 20 years. The history and further laboratory investigations indicated that the infertility was caused by high-titre sperm antibodies in the female. The antibodies blocked sperm-zona binding and reacted with a prominent band at 65 kD in Western blots. Preliminary studies indicate that a subset of the patients antibodies are specific for a unique protein sequence expressed by a cDNA testis library. This antigen may have potential for immunocontraceptive vaccine development.

Tests of human sperm function and fertilization in vitro

OBJECTIVEnTo review recent studies on the development of new tests of human sperm function and evaluation of which sperm characteristics are most important for fertilization in vitro by logistic regression analysis.nnnSTUDY SELECTIONnRecent studies on the relationship between putative and new tests of human sperm function and fertility in vitro or in vivo are discussed in this review. Some physiological and technical aspects are included.nnnMAIN OUTCOME MEASURESnFertilization rates in vitro and sperm tests including standard semen analysis, improved morphology assessment, objective assessment of sperm motility and movement characteristics, nuclear maturity, hypo-osmotic swelling, the acrosome and the acrosome reaction, acrosin activity, human sperm-hamster oocyte penetration assay, and sperm-zona pellucida (ZP) and sperm-oolemma binding.nnnRESULTSnThe percentages of sperm with normal morphology and a normal intact acrosome, mean linearity, and the number of sperm binding to the ZP were highly significant related to fertilization rates in vitro. Other sperm tests evaluated usually provided no additional information about fertilization rates. The human ZP is highly selective for binding of morphologically normal sperm. Acrosome-reacted human sperm have little or no ability to bind to the ZP.nnnCONCLUSIONnResults of in vitro fertilization can be used to evaluate tests of human sperm function. Logistic regression analysis is a powerful method for determining which groups of sperm characteristics are independently related to fertilization rates. Normal morphology, linearity, acrosome status, and sperm-ZP binding are the most important characteristics for fertilization in vitro.

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 less than 30% of sperm with normal morphology, there was a highly significant relationship between IVF rate and sperm-zona pellucida binding and a weaker relationship with sperm morphology. In conclusion, the sperm-zona pellucida binding ratio test is useful for predicting sperm fertilizing ability in vitro, particularly in men with poor sperm morphology.