P1003 The shorter the interval between preconceptional disease activity and pregnancy, the greater the risk of disease activity during pregnancy: Evidence from a large Dutch cohort
Authors: Bouwknegt D G , Dijkstra G , van Dop W A , van der Woude C J , Visschedijk M C ,   Dutch Initiative on Crohn and Colitis (ICC)
Published: January 2025

Abstract

Background
Inflammatory bowel disease (IBD) often coincides with pregnancy. It is well known that disease activity during pregnancy is associated with a higher incidence of adverse pregnancy outcomes 1–3. Previous studies have identified disease activity at conception as an important risk factor for activity later on during pregnancy. We aimed to explore other potential risk factors for activity during pregnancy in women who were in remission at conception, and report on pregnancy outcomes in a tertiary cohort in the Netherlands.

Methods
For this multicenter, retrospective cohort study, all adult female IBD-patients who had been pregnant during treatment in any of the three participating Dutch university medical centers between 2017 and 2022 were included. Data on patient- and disease characteristics, lab values, medication usage and pregnancy outcomes was extracted from the electronic patient records. Univariate and multivariate binary linear regressions were performed to investigate the relationship between having activity during pregnancy – defined as a fecal calprotectin of ≥200µg/L or the prescription of corticosteroids – and plausible risk factors including biological use, phenotype, disease duration, previous surgery, smoking, BMI, gravidity, and use of IVF. Finally, we evaluate the relationship between activity during pregnancy and pre-conceptional flares, divided over three time intervals: twelve to six months, six to three months, and less than three months prior to conception.

Results
In total, 432 women were included (61.6% Crohn’s disease, 35.6% ulcerative colitis), who together had been pregnant 716 times. In this cohort, 16.3% of pregnancies was lost before the 16th week. The adverse outcomes for the remaining pregnancies included the following: 10.8% low birthweight, 12.2% premature, 11.7% small for gestational age. Out of the pregnancies carried beyond 16 weeks, a flare occurred in 27.6% of cases. Preconceptional flares were significantly associated with a flare during pregnancy if they occurred within three months prior to conception (OR 9.8, 95%CI 3.8-25.1, p&lt;0.001), but not if they occurred six to three months prior (OR 3.7, 95%CI 1.0-14.1, p=0.058) or twelve to six months prior (OR 2.0, 95%CI 0.7-5.7, p=0.184). In multivariate analysis, increasing disease duration was associated with a lower risk of activity during pregnancy (OR 0.9, 95%CI 0.9-1.0, p=0.047). No further significant correlations were found (Table 1).

Conclusion
With a shorter interval between a flare and conception, the risk of relapse during pregnancy increases. Further analyses based on remission rather than activity could show the ideal period of time a woman should be free of activity before attempting to conceive.

References
1.Tandon P, Govardhanam V, Leung K, Maxwell C, Huang V. Systematic review with meta-analysis: risk of adverse pregnancy-related outcomes in inflammatory bowel disease. Aliment Pharmacol Ther. 2020;51(3):320-333. doi:10.1111/apt.15587
2.Leung KK, Tandon P, Govardhanam V, Maxwell C, Huang V. The Risk of Adverse Neonatal Outcomes with Maternal Inflammatory Bowel Disease: A Systematic Review and Meta-analysis. Inflamm Bowel Dis. 2021;27(4):550-562. doi:10.1093/ibd/izaa122
3.Kim MA, Kim YH, Chun J, et al. The Influence of Disease Activity on Pregnancy Outcomes in Women with Inflammatory Bowel Disease: A Systematic Review and Meta-Analysis. J Crohns Colitis. 2021;15(5):719-732. doi:10.1093/ecco-jcc/jjaa225