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 PCOS, while 40% of all women who seek fertility treatment have PCO/PCOS.
Dr. Agrawal said: "We observed a significantly higher prevalence of PCO/PCOS in lesbian compared with heterosexual women. Our initial results are also suggestive of a significantly greater hyperandrogenism in lesbian compared with heterosexual women.
The blood samples revealed that hormones such as testosterone, androstenedione, free testosterone index and luteinizing hormone (LH) were significantly higher, and sex hormone binding globulin (SHBG) was significantly lower in lesbian women compared with heterosexual women. Dr. Agrawal said: "When we compared lesbian and heterosexual women with PCOS, lesbian women had significantly higher androgens and lower SHBG compared with heterosexual women. We found a similar result in women with PCO only, but in lesbian and heterosexual women with normal ovaries, the androgens and SHBG levels were similar."
She continued: "Our research neither suggests nor indicates that PCO/PCOS causes lesbianism, only that PCO/PCOS is more prevalent in lesbian women. We do, however, hypothesize that hyperandrogenism, which is associated with PCOS, may be one of the factors contributing to the sexual orientation of women."
However, the researchers are quick to dismiss any idea that if this was the case, then treatments for PCOS could also be seen as a "cure" for lesbianism. Dr. Agrawal said: "In 1973 the decision to remove homosexuality from the list of mental disorders was made and since then the focus has shifted from the 'cure' of homosexuality to the physical and psychological health concerns of these individuals. We do not view lesbianism as a disease that is in need of a 'cure'. The only aspects of health care we offer these women are reproductive health and assisted reproduction."
Previous studies have shown a similar prevalence of sexually transmitted diseases among lesbian compared with heterosexual women, but had not investigated the effect of this on the women's Fallopian tubes. Dr. Agrawal's study showed that there was a similar incidence of Fallopian tube disease in both groups. "The importance of this finding is to make clinicians aware that sexually transmitted diseases are just as prevalent in lesbian women as in heterosexual women. Previous studies have shown that at least 70% of lesbian women have been heterosexual or bisexual previously. Sexual practices amongst the remaining 30% who have never been heterosexual means that STDs can be transmitted between women sexually.
Dr. Agrawal concluded: "There are several challenges and gaps in the research and healthcare of homosexual people, and this in itself calls for focus and funding of this aspect of medicine. In the past 20 years only 0.1% of published articles were dedicated to the healthcare of homosexual individuals, and before 1990 homosexual people were invisible to healthcare research. Our study emphasizes the importance of treating these women in a non-judgmental and non-biased manner so that clinicians may offer them appropriate health advice. I hope that this study will provide an impetus and motivation to clinicians and reproductive endocrinologists to investigate and explore further the hypothesis outlined here."
Abstract no: O-070 (Monday 30 June, 15.15 hrs CET, Roma room)
 Although PCOS is common cause of infertility in women, this does not mean that infertility is more common in lesbian women than in heterosexuals; in fact the opposite is true, and pregnancy rates are higher in lesbian compared to heterosexual women.
 Hyperandrogenism is caused by abnormally high concentrations of androgens (male steroid hormones in women). Symptoms range from excess facial and body hair, to baldness, acne, deepening of the voice and loss of breast tissue.
 SHBG is a protein that binds testosterone and other sex hormones. Women with PCOS may have normal concentrations of total testosterone, but their SHBG is lowered and therefore free testosterone concentrations are elevated, which results in symptoms related to hyperandrogenism.
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