Ovarian Function and Reproductive Hormone Levels in Girls with Prader-Willi Syndrome: A Longitudinal Study

Context: The etiology of hypogonadism in girls with Prader-Willi syndrome (PWS) remains uncertain. Objectives: The aim of the study was to evaluate gonadal function longitudinally in girls and female adolescents with PWS. Measurements: We performed a longitudinal assessment of anti-Müllerian hormone (AMH), gonadotropins, estradiol (E2), inhibin B and A, and pubertal development in girls and female adolescents with PWS. Patients and Methods: Sixty-one girls participating in the Dutch PWS Cohort study participated in the study. Serum AMH, gonadotropins, E2, and inhibin B and A levels were compared with reference values. Results: AMH levels in girls and female adolescents with PWS were comparable to reference levels between 6 months and 22 yr of age. From 10 yr of age, FSH and LH levels increased to above the 5th percentile compared to reference levels. E2 and inhibin B levels were in the low normal range in the majority, and inhibin A levels were low but detectable in almost half the female adolescents with PWS. The median age at puberty onset was comparable, but the median ages at attaining Tanner M3 (P = 0.05) and M4 (P < 0.0001) were significantly higher in girls with PWS than in healthy references. Conclusion: Our study shows that the primordial follicle pool and number of small antral follicles are conserved in girls and female adolescents with PWS. We found no classical hypogonadotropic hypogonadism. However, maturation of follicles and progression of pubertal development are impaired, which might be due to dysregulation of LH secretion. Because these impairments are not absolute, ovulation and thus conception cannot be ruled out in individual female adolescents with PWS.