Maternal age and adverse pregnancy outcome: a cohort study

ABSTRACT Objective To examine the association between maternal age and a wide range of adverse pregnancy outcomes after adjustment for confounding factors in obstetric history and maternal characteristics . Methods This was a retrospective study in women with singleton pregnancies attending the first routine hospital visit at 11 + 0 to 13 + 6 weeks' gestation. Data on maternal characteristics, and medical and obstetric history were collected and pregnancy outcomes ascertained. Maternal age was studied, both as a continuous and as a categorical variable. Regression analysis was performed to examine the association between maternal age and adverse pregnancy outcome including pre‐eclampsia, gestational hypertension, gestational diabetes mellitus ( GDM ), preterm delivery, small‐for‐gestational age ( SGA ) neonate, large‐for‐gestational age ( LGA ) neonate, miscarriage, stillbirth and elective and emergency Cesarean section . Results The study population included 76 158 singleton pregnancies with a live fetus at 11 + 0 to 13 + 6 weeks. After adjusting for potential maternal and pregnancy confounding variables, advanced maternal age (defined as ≥ 40 years) was associated with increased risk of miscarriage (odds ratio ( OR ), 2.32 (95% CI , 1.83–2.93) ; P < 0.001), pre‐eclampsia ( OR , 1.49 (95% CI , 1.22–1.82) ; P < 0.001), GDM ( OR , 1.88 (95% CI , 1.55–2.29) ; P < 0.001), SGA ( OR , 1.46 (95% CI , 1.27–1.69) ; P < 0.001) and Cesarean section ( OR , 1.95 (95% CI , 1.77–2.14) ; P < 0.001), but not with stillbirth, gestational hypertension, spontaneous preterm delivery or LGA . Conclusions Maternal age should be combined with other maternal characteristics and obstetric history when calculating an individualized adjusted risk for adverse pregnancy complications. Advanced maternal age is a risk factor for miscarriage, pre‐eclampsia, SGA , GDM and Cesarean section, but not for stillbirth, gestational hypertension, spontaneous preterm delivery or LGA . Copyright © 2013 ISUOG. Published by John Wiley & Sons Ltd .