Bariatric surgery could increase ovulation in women with PCOS

A study of women with polycystic ovary syndrome (PCOS) has shown that bariatric surgery led to a higher rate of spontaneous ovulation than other weight loss interventions.  

PCOS is believed to affect one in ten women in the UK, and approximately 50 percent of women with PCOS are overweight or obese, which can exacerbate some symptoms. The BAMBINI study compared the impact of bariatric surgery on ovulation in women with PCOS and irregular menstruation, to other interventions for obesity, including weight loss medication and behavioural modification.

'As the first trial of its kind to compare bariatric surgery with medical treatments for obesity, and the first to examine its safety as an option, the results will help women with PCOS and healthcare professionals make better informed decisions about treatment,' said Professor Alexander Miras, clinical professor of medicine at the Ulster University School of Medicine and lead of the study. 

The study, published in The Lancet, included 63 women with PCOS and a BMI over 35, who were proportionately and randomly allocated to the bariatric surgery (sleeve gastrectomy) group, or for behavioural interventions and pharmaceutical therapy (metformin and/or Orlistat).

Women had ovulation detected in the 52 weeks of follow-up using weekly serum progesterone. Women in the surgical group had six ovulations detected over that period, on average, and women in the behavioural and medical intervention group, two. Ovulation also started sooner after surgery than after starting behavioural and pharmaceutical interventions.

Pregnancy was not intended as an outcome of the study, but one occurred in the surgical group, and two pregnancies occurred in the behavioural intervention and pharmaceutical therapy group.

Significantly more weight was lost by women who had surgery, than those in the other group. The patients in the surgical group showed significantly healthier markers of heart and metabolic disease, compared to those who did not, which could translate into less complicated pregnancies, authors noted.

Surgery was risker overall, with at least five out of thirty women who had surgery being treated for side-effects. While seven women started taking Orlistat, just two were still taking it by the end of the study. Rates of low folic acid, crucial for development in early pregnancy, was higher in the surgical group. Authors noted it was recommended that pregnancy does not take place for 12-18 months after bariatric surgery.

'This breakthrough in fertility research is one that we hope will change the outcomes for many women who have experienced challenges when trying to conceive, or who are struggling with the effects of PCOS on their life,' said Tim Brundle, director of research and impact at Ulster University.

Many countries restrict access to IVF for women with higher BMIs. Authors note that this study could support bariatric surgery being offered to women with obesity and PCOS-related anovulatory infertility.