Objective: To assess the relationship between the concentrations of total immunoreactive alpha-inhibin in human seminal plasma, sperm quality, and in vitro fertilization (IVF) rates.
Setting: Medical school hospital.
Design: Prospective study.
Patients: 72 consecutive couples undergoing IVF with husband's sperm in which at least 4 oocytes were obtained.
Main outcome measures: Alpha-inhibin determination by means of enzyme-linked immunosorbent assay, sperm analysis for density and motility, IVF rates.
Results: Total immunoreactive alpha-inhibin levels were not correlated with IVF rates. Nor were there any differences in fertilization rates in the different groups. Lower inhibin levels were found in oligozoospermic cases. Lower sperm counts were found in cases with inhibin values below the median value, and also with respect to various other cutoffs. No correlation was found between inhibin levels and any of the sperm variables measured.
Conclusion: Total immunoreactive alpha-inhibin is not a prognostic factor in IVF cycles. However, an association was found between inhibin and sperm concentration, suggesting that alpha-inhibin in the human seminal fluid could be a marker for some aspects of spermatogenesis.