P633. Inflammatory bowel disease and risk of pre-eclampsia and preterm delivery: a national birth cohort study
M. Harpsøe1, H. Boyd1, S. Usmann1, J. Wohlfahrt1, T. Jess1, 1Statens Serum Institut, Department of Epidemiology Research, Denmark
Inflammatory bowel disease (IBD) in pregnancy has been associated with adverse pregnancy outcomes, but study findings are inconsistent. We investigated the influence of Crohn's disease (CD) and ulcerative colitis (UC) on risk of pre-eclampsia and preterm delivery in a large prospective cohort study.
Using information from the Danish Hospital Discharge Register and the Danish National Birth Cohort, we followed a cohort of >84,000 singleton pregnancies for pre-eclampsia and preterm delivery (delivery <37 weeks). We estimated hazard ratios (HRs) using Cox regression, adjusting for parity, socioeconomic status, maternal pre-pregnancy body mass index, and maternal smoking and alcohol consumption during pregnancy.
IBD was diagnosed prior to pregnancy in 1,519 women. Women with IBD were almost 1.5 times as likely as women without IBD to develop pre-eclampsia (HR 1.49, 95% confidence interval [CI] 0.96–2.31); the risks associated with CD and UC separately were of similar magnitudes but not statistically significant. Overall, women with UC (HR 2.01, 95% CI 1.39–2.89) but not CD (HR 1.17, 95% CI 0.68–2.01) had a significantly increased risk of preterm delivery. This was explained by an increased risk of spontaneous preterm delivery in women with UC (HR 1.78, 95% CI 0.96–3.31), whereas both UC (HR 2.67, 95% CI 1.55–4.61) and CD (HR 2.41, 95% CI 1.25–4.64) increased the risk of medically indicated preterm delivery.
Our national birth cohort study showed that women with IBD are at increased risk of pre-eclampsia and of medically indicated preterm delivery.