Background: Low birthweight is associated with adult-onset hypertension, cardiovascular disease (CVD), stroke and type 2 diabetes. The link between pregnancy complications and subsequent CVD is now well established. We examined the influence of maternal birthweight on the risk of development of pregnancy complications including preeclampsia (PE), gestational hypertension (GHTN), small for gestational age (SGA) pregnancy, spontaneous preterm birth (sPTB) and gestational diabetes mellitus (GDM).
Methods: This study includes 5336 women from SCOPE, a multicentre prospective cohort study. Nulliparous women were recruited during their first pregnancy in Adelaide, Australia; Auckland, New Zealand; Manchester and Leeds, UK and Cork, Ireland. Detailed information was collected at 15 and 20 weeks’ gestation and the women were followed up throughout pregnancy. The woman’s birthweight and gestational age at birth were self-reported and confirmed via medical records when possible. A maternal birthweight of 2500-3500g was considered the reference.
Results: Maternal birthweight<2500g was associated with increased risk of PE (OR=1.8, 95% CI=1.2-2.8), having a SGA infant (OR=1.5, 95% CI=1.1-2.1), sPTB (OR=1.9, 95% CI=1.1-3.1) and GDM (OR=1.8, 95% CI=1.0-3.1) compared to the reference group. Maternal birthweight≥4000g was associated with a reduced risk of PE (OR=0.6, 95% CI=0.3-0.9) and SGA (OR=0.4, 95% CI=0.3-0.6) compared to the reference group. All results remained significant after correcting for maternal age, BMI smoking at 15 weeks’ gestation, infant sex and maternal gestational age at birth.
Conclusion: Our results demonstrate that women who are small at birth are at increased risk of preeclampsia, gestational diabetes, spontaneous preterm birth and SGA infants compared to women who have uncomplicated pregnancies. Considering that women who develop any of these pregnancy complications are at approximately double the risk of subsequent CVD, these findings add to existing literature that low birthweight appears to be one factor that contributes to the risk for pregnancy complications and subsequent CVD.