Metformin, pre-eclampsia, and pregnancy outcomes in women with polycystic ovary syndrome.

AIMS: Was metformin during pregnancy in women with polycystic ovary syndrome (PCOS) associated with pre-eclampsia, and was it safe for mother and neonate?

METHODS: In the current study, pre-eclampsia and other pregnancy outcomes were prospectively studied in 90 women with PCOS who conceived on metformin 1.5-2.55 g/day, and had > or = 1 live birth (97 pregnancies, 100 live births) compared with 252 healthy women (not known to have PCOS) with > or = 1 live birth, consecutively delivered in a community obstetrics practice.

RESULTS: Women with PCOS were older than controls (33 +/- 5 vs. 29 +/- 6 years, P < 0.0001), more likely to be > 35 years old at conception (23 vs. 13%, P = 0.028), much heavier (93 +/- 23 vs. 72 +/- 18 kg, P < 0.0001, BMI 33.8 +/- 7.8 kg/m2 vs. 25.6 +/- 5.9, P < 0.0001), and more likely to be Caucasian (97 vs. 90%, P = 0.05), but there were similar numbers with preconception Type 2 diabetes mellitus [2/90 (2.2%) vs. 1/252 (0.4%), P = 0.17]. Pre-eclampsia in PCOS (5/97 pregnancies, 5.2%), did not differ (P = 0.5) from controls (9/252, 3.6%), nor did it differ (P = 1.0) in PCOS vs. control primigravidas [2/45 (4.4%) vs. 4/91 (4.4%)]. Development of gestational diabetes in PCOS did not differ from controls [9/95 pregnancies (9.5%) vs. 40/251 (15.9%), P = 0.12]. Of the 100 live births to 90 women with PCOS, there were no major birth defects. Mean +/- sd birth weight of the 80 live births > or = 37 weeks gestation in women with PCOS (3414 +/- 486 g) did not differ from controls' 206 live births > or = 37 weeks (3481 +/- 555 g), P = 0.34, nor did the percentage of > or = 37 week gestation neonates > or = 4000 g (12.5 vs. 17.5%, P = 0.3) or > or = 4500 g (1.3 vs. 2.9%, P = 0.7).

CONCLUSIONS: Metformin is not associated with pre-eclampsia in pregnancy in women with PCOS, and appears to be safe for mother and fetus.