Metformin reduces pregnancy complications without affecting androgen levels in pregnant polycystic ovary syndrome women: results of a randomized study

BACKGROUND: Investigation of a possible effect of metformin on androgen levels in pregnant women with polycystic ovary syndrome (PCOS). METHODS: A prospective, randomized, double-blind, placebo-controlled pilot study was conducted. Forty pregnant women with PCOS received diet and lifestyle counselling and were randomized to either metformin 850 mg twice daily or placebo. Primary outcome measures were changes in serum levels of dehydroepiandrosterone sulphate, androstenedione, testosterone, sex hormone-binding globulin, and free testosterone index. Secondary outcome measures were pregnancy complications and outcome. Two-tailed t-tests and χ2-tests were used. RESULTS: Maternal androgen levels were unaffected by metformin treatment in pregnant women with PCOS. While none of the 18 women in the metformin group experienced a severe pregnancy or post-partum complication, seven of the 22 (32%) women experienced severe complications in the placebo group (P=0.01). CONCLUSIONS: Metformin treatment did not reduce maternal androgen levels in pregnant women with PCOS. In the metformin-treated group we observed a reduction of severe, pregnancy and post-partum complications. Metformin treatment of pregnant PCOS women may reduce complications during pregnancy and in the post-partum period.