Inhibin B is a better marker of spermatogenesis than other hormones in the evaluation of male factor infertility

Objective: To assess the role of inhibin B in the evaluation of male factor infertility. Design: Prospective study. Setting: Reproductive endocrinology clinic. Patient(s): Seventy-five patients with infertility problems (mean age 31.2 ± 7.5 years) and 12 controls (32.1 ± 8.8 years) with proven fertility. Intervention(s): None. Main Outcome Measure(s): Semen analysis was performed according to World Health Organization guidelines. Testicular volume was assessed with the Prader's orchidometer. Serum levels of inhibin B (pg/mL), LH (mIU/mL), FSH (mIU/mL), prolactin (micro IU/mL), and testosterone (nmol/L) were assessed. Result(s): The mean ± SEM inhibin B and testosterone levels were significantly lower in the patients than in the controls (inhibin B: 116.4 ± 11.7 vs. 181.2 ± 20.9, P=.008; testosterone: 13.6 ± 0.9 vs. 25.1 ± 2.9, P=.008). In general, sperm count and testicular volume in the patients were significantly and positively correlated with inhibin B (sperm count: r = 0.476, P