Therapeutic Benefits of Gonadotropins in Male Hypogonadotropic Hypogonadism

74% of azoospermic men produced sperm on hormone therapy; combination outperformed monotherapy 78% vs 33%

Journal: Reproduction & Fertility | Published: 2026-06-16 | Type: Retrospective cohort study | PMID: 42189927 Authors: Huijben M et al., University Medical Center Utrecht (multidisciplinary team: urology, endocrinology, gynecology) Funding/COI: Not listed for either

Summary

Men with hypogonadotropic hypogonadism (HH) — a condition where the brain fails to signal the testes to make sperm or testosterone — can often be treated with injected gonadotropins. This single-center Dutch study tracked 35 azoospermic men through treatment and found that three-quarters produced sperm, most within seven months, and two-thirds went on to achieve pregnancy. The headline finding is that combining hCG with FSH worked substantially better than hCG alone.

Claims

• Spermatogenesis was achieved in 74% of patients (26/35)
• Combined hCG + FSH therapy: 78% success rate; hCG monotherapy: 33% success rate
• Of those who produced sperm, 69% upgraded to a higher WHO semen quality category; 29% reached normospermia
• Median maximum sperm concentration during treatment: 8.3 million/mL (IQR: 1.9–36.3)
• Larger baseline testicular volume was associated with higher spermatogenesis success and shorter time to pregnancy
• Pregnancy achieved in 68% of patients; 39% through spontaneous conception
• Median time to first spermatogenesis: 7 months; median time to pregnancy: 21 months
• Mild side effects (not specified further) in 16% of patients

Study Quality

This is a retrospective single-center cohort — a design appropriate for a rare condition where prospective RCTs are difficult to run, but one that carries the usual baggage: no control group, no randomization, and susceptibility to selection and ascertainment bias. The sample of 35 men is small, which makes subgroup comparisons unreliable. The 78% vs 33% comparison between combination therapy and monotherapy is the study's most cited-worthy finding, but the monotherapy arm almost certainly contains fewer patients — the paper doesn't break down group sizes in the abstract, making that contrast hard to evaluate without reading the full tables.

Follow-up was long enough to capture pregnancy outcomes (median 21 months), which is a meaningful endpoint rather than just semen parameters. Regression analyses were used to identify predictors of success, but multivariate modeling in a sample of 35 is statistically fragile — you can overfit almost anything with that many candidate predictors.

Red Flags

• n = 35 is very small; any subgroup analysis is underpowered
• Retrospective design can't control for confounders (e.g., severity of HH at baseline, adherence differences between treatment arms)
• Treatment assignment was not randomized — men on monotherapy may have differed systematically from those on combination therapy
• Funding and conflicts of interest not disclosed; pharma ties for gonadotropin studies are common and worth knowing
• "Mild side effects in 16%" is vague — no breakdown of what those were or how severity was assessed
• Single-center data from a Dutch academic center may not generalize to other healthcare settings or patient populations

Strengths

• Tracks clinically meaningful outcomes (pregnancy, not just sperm count)
• Long enough follow-up to capture full fertility trajectory
• Includes both semen parameters and WHO category upgrades, giving a richer picture of response quality
• Multidisciplinary team (urology + endocrinology + gynecology) reduces siloed data collection
• Contemporary Western cohort — fills a gap since much prior HH literature comes from older or non-Western populations

Verdict

A small, methodologically modest study that nonetheless gives clinicians real-world numbers for a condition that's rare enough to make large trials impractical. The combination hCG + FSH finding is plausible and consistent with prior literature, but the sample size makes the 78% vs 33% comparison more suggestive than definitive. The 21-month median time to pregnancy is the kind of concrete, counseling-relevant data point that's genuinely useful even from a study this size. Worth reading for the numbers; don't treat the subgroup comparisons as settled.