Supplementary Material for: Efficacy and Safety of Continuous Subcutaneous Infusion of Recombinant Human Gonadotropins for Congenital Micropenis during Early Infancy

<i>Background:</i> Early postnatal administration of gonadotropins to infants with congenital hypogonadotropic hypogonadism (CHH) can mimic minipuberty, thereby increasing penile growth. We assessed the effects of gonadotropin infusion on stretched penile length (SPL) and hormone levels in infants with congenital micropenis. <i>Methods:</i> Single-center study including 6 males with micropenis in case of isolated CHH (<i>n</i> = 4), panhypopituitarism (<i>n</i> = 1), and partial androgen insensitivity syndrome (PAIS; <i>n</i> = 1). Patients were evaluated at baseline, monthly and at the end of the study through a clinical examination (SPL, testicular position and size), serum hormone assays (testosterone, luteinizing hormone, follicle-stimulating hormone, inhibin B, anti-Müllerian hormone [AMH]), and ultrasound of penis/testes. <i>Results:</i> In CHH, significant increases occurred in serum testosterone (from undetectable level to 3.5 ± 4.06 ng/mL [12.15 ± 14.09 nmol/L]), SPL (from 13.8 ± 4.5 to 42.6 ± 5 mm; <i>p</i> < 0.0001), inhibin B (from 94.8 ± 74.9 to 469.4 ± 282.5 pg/mL, <i>p</i> = 0.04), and AMH (from 49.6 ± 30.6 to 142 ± 76.5 ng/mL, <i>p</i> = 0.03). Micropenis was corrected in all patients, except one. On treatment, in the patient with PAIS, SPL was increased from 13 to 38 mm. <i>Conclusions:</i> Early gonadotropin infusion is a safe, well-tolerated and effective treatment. The effect in PAIS has not been reported previously. Long-term follow-up is needed to assess the impact, if any, on future fertility and reproduction.