Maternal Obesity Is Associated With Adverse Pregnancy Outcomes in Inflammatory Bowel Disease: A Matched Electronic Health Record Cohort Study
Christopher Roberts, Rebecca Smith, Safwat Odeh, Nathan Kuk, Ayushi Chauhan, Claire Bewshea, Vida Cairnes, Hayley Toll, Nick Kennedy, James Goodhand, Tariq Ahmad, Jennifer Blackman, Alex Bain, Sally Bell, Jennie CloughABSTRACT
Background
We sought to define the prevalence of obesity in the first trimester of pregnancy among women with inflammatory bowel disease (IBD) and evaluate its association with adverse pregnancy outcomes.
Methods
First‐trimester body mass index (BMI) was assessed in pregnancies with and without IBD. Pregnancies reaching 24 weeks were propensity‐score matched 1:6 by maternal age, BMI, smoking status and gravidity to assess whether IBD conferred additional pregnancy risk.
Results
Overall, 22.6% (64/283; 95% CI 17.7%–27.5%) of pregnancies in women with IBD met ethnicity‐adjusted criteria for obesity. Increasing obesity class was associated with stepwise increases in gestational diabetes, pre‐eclampsia, venous thromboembolism (VTE), emergency caesarean section and high birthweight. Matching yielded 177 IBD pregnancies and 1062 controls. Obesity was independently associated with the composite adverse pregnancy outcome (OR 1.63; 95% CI 1.15–2.33; p = 0.007), whereas no statistically significant additional association was identified for IBD diagnosis alone (OR 0.74; 95% CI 0.53–1.03; p = 0.073). Among IBD pregnancies, aspirin was recommended in 39.3% (86/219). Low‐molecular‐weight heparin (LMWH) was prescribed in 21.6% (19/88) of pregnancies classified post hoc as intermediate or high VTE risk.
Conclusion
More than one in five pregnancies in women with IBD were complicated by obesity. Obesity was strongly associated with adverse pregnancy outcomes, whereas this study did not identify a significant additional effect attributable to IBD diagnosis alone. Preventive prescribing with aspirin and LMWH represents an opportunity for improved antenatal care.