P olycystic ovaries are seen at ultrasound in 20-25% of women, and the prevalence of polycystic ovary syndrome (PCOS) seems to be rising because of the current epidemic of obesity.1 The syndrome accounts for 90-95% of women who attend infertility clinics with anovulation. The considerable risks in pregnancy associated with obesity are not usually appreciated when patients with PCOS attend clinics and request fertility treatment. Is it appropriate to offer treatment or to insist on weight loss? Or does any overweight woman have the right to receive treatment, irrespective of the possible outcome?

The syndrome is defined by any two out of the following criteria: infrequent or absent menstruation, indicating anovulation; hyperandrogenism; and polycystic ovaries diagnosed by ultrasound after the exclusion of other aetiologies of menstrual disturbance and hyperandrogenism.2 At least 40% of women with PCOS are obese,1 and they are more insulin resistant than weight matched women with normal ovaries. …