Background: Polycystic ovaries are a common disorder associated with menstrual irregularities, subfertility, hirsutism, acne, and a range of endocrine abnormalities, including high concentrations of plasma luteinising hormone (LH) and excessive androgen production. The pathophysiology is not understood. We investigated whether the disorder originates during intrauterine life.
Methods: We examined 235 women aged 40-42 years who were born in Sheffield, UK. We related the prevalence of polycystic ovaries and the plasma concentrations of gonadotropin hormones and androgens to the women's body size at birth, and the length of gestation.
Findings: 49 (21%) of the women had polycystic ovaries. We defined two groups of women with the disorder, which correspond to the two groups that commonly present clinically. The first group comprised obese women who were androgenised, with higher than normal concentrations of plasma LH and testosterone. These women had above-average birthweight and were born to overweight mothers. The second group comprised women of normal weight who had high plasma LH, but normal testosterone concentrations. These women were born after term (40 weeks' gestation).
Interpretation: The two common forms of polycystic ovary syndrome have different origins in intrauterine life. Obese, hirsute women with polycystic ovaries have higher than normal ovarian secretion of androgens that are associated with high birthweight and maternal obesity. Thin women with polycystic ovaries have altered hypothalamic control of LH release resulting from prolonged gestation.