Endocrine features of polycystic ovary syndrome in a random population sample of 14–16 year old adolescents

Hospital based studies have shown that oligomenorrhoeic adolescents have high luteinizing hormone (LH) and androgen concentrations, endocrine signs of polycystic ovary syndrome (PCOS). The prevalence of these abnormalities in an unselected population of adolescents is not known. We determined LH, follicle stimulating hormone (FSH), androstenedione, testosterone, dehydroepiandrosterone sulphate (DHEAS), oestradiol and prolactin concentrations in unselected population samples of adolescents with oligomenorrhoea, secondary amenorrhoea and regular menstrual cycles. A total of 2248 white, west European adolescents, aged 15.3 ± 0.6 (mean ± SD) years, participated. Blood was taken from 107 adolescents with regular menstrual cycles, 52 with oligomenorrhoea and four with secondary amenorrhoea. Oligomenorrhoeic adolescents had higher mean LH, androstenedione, testosterone, DHEAS and oestradiol concentrations compared with girls with regular menstrual cycles; 57% of the oligomenorrhoeic girls had LH or androgen concentrations above the 95th centile of adolescents with regular menstrual cycles. None of the 52 oligomenorrhoeic girls and only one of four girls with secondary amenorrhoea had a hypogonadotrophic endocrine pattern. The present study and available literature support the view that oligomenorrhoea in adolescents is not a stage in the physiological maturation of the hypothalamic pituitary-ovarian axis but an early sign of PCOS associated with subfertility. Physicians should consider endocrine evaluation before reassuring oligomenorrhoeic girls or prescribing oral contraceptives to these girls.