Clinical review: Adolescent anovulation: maturational mechanisms and implications

Abstract

Context: Adolescents are at high risk for menstrual dysfunction. The diagnosis of anovulatory disorders that may have long-term health consequences is too often delayed.

Evidence acquisition: A review of the literature in English was conducted, and data were summarized and integrated from the author's perspective.

Main findings: Normal adolescent anovulation causes only minor menstrual cycle irregularity: most cycles range from 21-45 days, even in the first postmenarcheal year, 90% by the fourth year. Approximately half of symptomatic menstrual irregularity is due to neuroendocrine immaturity, and half is associated with increased androgen levels. The former is manifest as aluteal or short/deficient luteal phase cycles and usually resolves spontaneously. The latter seems related to polycystic ovary syndrome because adolescent androgen levels are associated with adult androgens and ovulatory dysfunction, but data are sparse. Obesity causes hyperandrogenemia and, via unclear mechanisms, seems to suppress LH; it may mimic polycystic ovary syndrome. The role of pubertal insulin resistance in physiological adolescent anovulation is unclear. High-sensitivity gonadotropin and steroid assays, the latter by specialty laboratories, are necessary for accurate diagnosis of pubertal disorders. Polycystic ovaries are a normal ultrasonographic finding in young women and are associated with nearly 2-fold increased anti-Müllerian hormone levels. Oral contraceptives are generally the first-line treatment for ongoing menstrual dysfunction, and the effects of treatment are similar among preparations.

Conclusions: Menstrual cycle duration persistently outside 21-45 days in adolescents is unusual, and persistence ≥ 1 year suggests that disordered hypothalamic-pituitary-gonadal function be considered. Research is needed on the mechanisms and prognosis of adolescent anovulation.

Figure 1.

Twenty-four-hour premenarcheal and postmenarcheal serum LH patterns in normal and hyperandrogenic girls. Significant pulses are designated by asterisks. A, Normal premenarcheal pubertal girl. Note sleep-related increase in LH. B, Normal postmenarcheal girl in early follicular phase of the menstrual cycle. Note nocturnal slowing of LH pulses. C, Hyperandrogenic premenarcheal girl. In the rare girl in whom hyperandrogenism is detected before menarche, LH elevation is most remarkable during sleep. D, Hyperandrogenic postmenarcheal girl. LH levels and pulse frequency are high. Note the absence of normal postmenarcheal nocturnal slowing, as is typical after an anovulatory cycle; LH levels tend to fall with sleep and to be highest midday. Note that both hyperandrogenic girls have higher, but not necessarily elevated, LH levels. [Modified and reproduced from D. Apter et al.: Accelerated 24-hour luteinizing hormone pulsatile activity in adolescent girls with ovarian hyperandrogenism: relevance to the developmental phase of polycystic ovarian syndrome. J Clin Endocrinol Metab. 1994;79:119–125 (84), with permission. © The Endocrine Society.]