Polycystic ovarian syndrome (PCOS) is the commonest cause of ovarian dysfunction in women and is caused by an imbalance of sex hormones. One of the main features of PCOS is hyperandrogenism, and now that the researchers have discovered the increased prevalence of PCOS amongst lesbian women they hypothesize that hyperandrogenism could be contributing to the women's sexual orientation.
Dr. Rina Agrawal, deputy medical director at the London Women's Clinic and The Hallam Medical Centre, and her colleagues examined 618 women who attended the clinic for fertility treatment between November 2001 and January 2003. Of these, 254 were lesbian and 364 were heterosexual women.
The women did not know whether they had polycystic ovaries (PCO) or PCOS before attending the clinic, but 15% of them had been treated previously for symptoms relating to PCOS such as irregular periods, inability to conceive, acne or excessive body or facial hair.
The women had a pelvic ultrasound examination on the second or third day of their menstrual cycle, and blood samples were taken to measure levels of reproductive hormones. A clinician, nurse and counsellor or clinical psychologist took details of their medical and sexual histories in three separate sessions.
The researchers found that the prevalence of PCO was 32% in heterosexual women and 80% in lesbian women, and that the prevalence of PCOS was 14% in heterosexual women and 38% in lesbian women. The average prevalence amongst all 618 women (lesbian and heterosexual) was 52% for PCO and 24% for PCOS. This compares with European data that show that the prevalence of PCO in the general population is 22% and 10-15% for PC
Contact: Emma Mason
European Society for Human Reproduction and Embryology