Adverse pregnancy outcomes among women with inflammatory bowel disease: a population based study from England

Background: There is limited contemporary population based evidence on adverse birth outcomes and pregnancy related complications for women with inflammatory bowel disease (IBD). This study provides such estimates of these risks and assesses variation by IBD type and surgical interventions.Methods: We calculated the proportion of pregnancies in women with and without IBD between 1997 and 2012 throughout England using linked primary (Clinical Practice Research Datalink-CPRD) and secondary care (Hospital Episode Statistics-HES) data. Risk of pregnancy related complications and adverse birth outcome in women with Crohn’s Disease-CD and Ulcerative Colitis-UC were compared to risks in women without IBD using odds ratios (OR).Results: Of 364,363 singleton pregnancies resulting in live or stillbirths 1,969 (0.5%) were in women with IBD. Women with CD were more likely to have pre-term births (OR=1.42 95%CI;1.12-1.79), babies with low birth weights (OR=1.39;1.05-1.83) and postpartum haemorrhage (OR=1.27;1.04-1.55) whereas women with UC were only at increased risk of pre-term births with an absolute risk difference o