Association between testosterone, semen parameters, and live birth in men with unexplained infertility in an intrauterine insemination population

Objective: To determine whether men with unexplained infertility and low total T (TT) have abnormal spermatogenesis and lower fecundity. Design: Secondary analysis of the prospective, randomized, multicenter clinical trial, Assessment of Multiple Intrauterine Gestations from Ovarian Stimulation (AMIGOS). Setting: Infertility clinics. Patient(s): Nine hundred couples with unexplained infertility enrolled in AMIGOS. Semen analysis with an ejaculate of at least 5 million total motile sperm was required for enrollment. For inclusion in this secondary analysis, a fasting TT was required. Intervention(s): None. Main Outcome Measure(s): Logistic regression, adjusted for age and body mass index, assessed the association between low TT (defined as <264 ng/dL), semen parameters, and pregnancy outcome. Result(s): Seven hundred eighty-one men (mean age, 34.2 ± 5.7 years) with a median (interquartile range) TT of 411 (318–520) ng/dL were included. Men with TT <264 ng/dL were less likely to have normal (≥4% strict Kruger) morphology (unadjusted odds ratio [OR], 0.56; 95% confidence interval [CI], 0.34, 0.92; adjusted OR, 0.59; 95% CI, 0.35, 0.99). There was no association between low TT and semen volume < 1.5 mL, sperm concentration < 15 × 10⁶/mL, or motility < 40%. Among couples whose male partner had low TT, 21 (18.8%) had a live birth, compared with 184 (27.5%) live births in couples with a male partner having TT > 264 ng/dL. The odds of live birth decreased by 40% in couples whose male partner had low TT (unadjusted OR, 0.60; 95% CI, 0.36, 1.00; adjusted OR, 0.65; 95% CI, 0.38, 1.12). Conclusion(s): In couples with unexplained infertility, low TT in the male partner was associated with abnormal sperm morphology and lower live birth rates. Clinical Trial Registration Number: NCT01044862.