Background: Malnutrition and weight loss are common features of patients with inflammatory bowel disease (IBD).
Aim: To explore the impact of inadequate gestational weight gain (GWG) on adverse outcomes among IBD mothers in the prospective US pregnancy in Inflammatory Bowel Disease and Neonatal Outcomes (PIANO) cohort.
Methods: The PIANO cohort comprises 559 and 363 pregnant mothers with Crohn's disease (CD) and ulcerative colitis (UC), respectively, enrolled between 2006 and 2014. The mothers were followed during and after pregnancy to ascertain medication, measurement of disease activity and complications during pregnancy and at delivery. Inadequate GWG was based on US Institute of Medicine recommendations. The associations between inadequate GWG and adverse pregnancy outcomes in maternal IBD were analyzed, adjusted for diabetes, hypertension, smoking, maternal age, education, and disease activity.
Results: Maternal CD and UC with inadequate GWG had a 2.5-fold increased risk of preterm birth (OR 2.5, CI 1.3, 4.9 and OR 2.5, CI 1.2, 5.6). Furthermore, an increased risk of intrauterine growth restriction and a trend for small for gestational age were demonstrated in CD but not in UC (OR 3.3, CI 1.1, 10.0, OR 4.5, CI 0.8, 24.3, p = 0.08). Flares increased risk of inadequate GWG (OR 1.6, CI 1.2, 2.3, p = 0.002) but did not change the associations between inadequate GWG and adverse pregnancy outcomes in our models.
Conclusion: The US PIANO cohort demonstrated that inadequate GWG was a strong independent predictor of adverse pregnancy outcomes in IBD mothers.
Keywords: Adverse pregnancy outcome; Disease activity; IBD; Inadequate gestational weight gain; PIANO cohort.