Obesity, polycystic ovary syndrome, infertility treatment

Editor—As Balen et al say,¹ epidemiological data show that obesity is associated with adverse pregnancy outcomes. However, long term maintenance of weight loss among obese populations is low, estimated at 15% over at least three years of follow-up in one systematic review.² Weight loss in shorter term studies, whether of dietary or pharmacologic treatments, six months to two years in duration, does not generally exceed a mean of 5-10 kg, and typically is closer to 3 kg, after accounting for placebo effects.

This translates to less than a 2-4 kg/m² reduction (or in more typical results, just over 1 kg/m²) in body mass index (BMI) for a woman of average height. These estimates are generous, because typical lifestyle and drug trials for weight loss suffer from non-compliance or dropout rates exceeding 30%,³ and participants who drop out of weight loss trials frequently do so because of treatment failure.⁴ This magnitude of weight loss is unlikely to be sufficient to alter the decision of a clinician who has already chosen to withhold treatment because of obesity, although as the authors indicate, it may be sufficient to improve ovulatory function in women with polycystic ovary syndrome.

To suggest therefore that obese women defer treatment until they achieve a particular BMI is equivalent to refusing most of these women reproductive care. Women are entitled to choose a less than ideal treatment if they have received appropriate information on risks, benefits, and effectiveness.

A health related quality of life measure has identified body weight, fertility, and menstrual problems as three of the five most important areas of concern for women with polycystic ovary syndrome.⁵ Although recommending weight loss is reasonable and prudent for all the reasons put forth by Balen et al, to suggest that obese women with the syndrome and infertility defer fertility treatment for a potentially indefinite period of time will only add to their sense of stigmatisation.