Inflammatory bowel disease and pregnancy outcomes

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A new systematic review and meta-analysis suggests that women with inflammatory bowel disease (IBD) may be at increased risk of adverse pregnancy outcomes such as gestational diabetes mellitus (GDM) and preterm premature rupture of membranes (PPROM). The authors caution, however, their results need to be confirmed in larger, prospective studies.

Methods
Published in Alimentary Pharmacology & Therapeutics, the findings are by Canadian researchers who searched Medline, Embase, and the Cochrane library through May 2019 for studies reporting adverse maternal, placental and obstetric outcomes in patients with IBD. Nearly 8000 pregnancies complicated by IBD and more than 3,200 control pregnancies were represented in the 53 studies selected for analysis. 

The authors hypothesized that women who took medication for IBD during pregnancy might have an increased risk of adverse outcomes such as cesarean delivery, GDM, preeclampsia, chorioamnionitis, placental abruption, PPROM, early pregnancy loss, elective termination of pregnancy, termination of pregnancy, and ectopic pregnancy. The medications considered were 5-aminosalicylates (5-ASA), corticosteroids, thiopurines, anti-tumor necrosis factor (TNF) therapy, vedolizumab, ustekinumab, and tofacitinib. 

Findings
Analysis of the data from the studies showed that cesarean delivery was more common in patients with IBD compared to healthy controls (OR 1.79, 95% CI 1.16 to 2.77). This remained significant for ulcerative colitis but not Crohn’s disease (OR 1.48, 95% CI 0.94 to 2.34). GDM also was more common in women with IBD (OR 2.95, 95% CI 1.47 to 5.98(. 

Incidences of placental disease were 2.0% (95% CI 0.9% to 3.1%) for preeclampsia, 3.3% (95% CI 0% to 7.2%) for placental abruption, 0.5% (95% CI 0.2% to 0.9%) for placenta previa and 0.3% (95% CI 0% to 0.5%) for chorioamnionitis. Women with IBD were more likely to experience PPROM (OR 12.10, 95% CI 2.15 to 67.98) but not early pregnancy loss (OR 1.63, 95% CI 0.49 to 5.43). 

Conclusions
Anti-TNF therapy was not associated with chorioamnionitis (OR 1.12, 95% CI 0.16 to 7.67), early pregnancy loss (OR 1.49, 95% CI 0.83 to 2.64) or placenta previa (OR 1.58, 95% CI 0.30 to 8.47). The authors noted, however, that the study sample sizes were small and control group comparisons were lacking so definitive conclusions about the drugs cannot be made. They are, however, in line with recent guidelines from the American Gastroenterological Association to continue anti-TNF therapy in pregnant women to maintain IBD remission.