Height, weight, and motor - Social development during the first 18 months of life in 126 infants born to 109 mothers with polycystic ovary syndrome who conceived on and continued metformin through pregnancy

Background: We prospectively assessed growth and motor-social development during the first 18 months of life in 126 live births (122 pregnancies) to 109 women with polycystic ovary syndrome (PCOS) who conceived on and continued metformin (1.5-2.55 g/day) through pregnancy. Methods: The lengths and weights of PCOS neonates were compared with gender-specific Centers for Disease Control and Prevention (CDC) infant data. Gestational diabetes (GD) and pre-eclampsia in women with PCOS were compared with 252 healthy women without PCOS who had ≥1 live birth (262 live births). Results: There were 101 out of 126 (80%) term (≥37 gestational weeks) PCOS births, which was not significantly different (P = 0.7) from controls, 206 out of 252 (81.7%). There were two (1.6%) birth defects. GD occurred in nine out of 119 PCOS pregnancies (7.6%) versus 40 out of 251 (15.9%) controls, P = 0.027. The prevalence of pre-eclampsia did not differ in PCOS versus control pregnancies (4.1 versus 3.6%, P = 0.8). The birth length and weight of the 52 male neonates did not differ (P > 0.05) from those of CDC males; the 74 female neonates were shorter than CDC females (48.9 ± 5.4 versus 50.6 ± 2.7 cm, P = 0.006) and weighed less (3.09 ± 0.85 versus 3.29 ± 0.52 kg, P = 0.04). There were no systematic differences in growth between PCOS and CDC infants over 18 months. At 3, 6, 9, 12 and 18 months, of a potential 100% motor-social development score, scores (±SD) were 95 ± 13, 98 ± 8%, 95 ± 10, 97 ± 8 and 94 ± 16%; no infants had motor-social developmental delays. Conclusions: Metformin reduced development of GD, was not teratogenic and did not adversely affect birth length and weight, growth or motor-social development in the first 18 months of life.