Using French national health data system (SNDS) data, we identified all
pregnancies ending between 1 April 2010 and 31 December 2018 in patients with
and without IBD in France. Pregnancy and IBD characteristics were described.
Pregnancy outcomes were compared between IBD and non-IBD pregnancies using
multivariable logistic regression models.

We included 36 654 IBD and 8 595 562 non-IBD pregnancies. Among IBD
pregnancies, 75.6% ended in live births and 0.4% in stillbirths. Pregnancies in women
with IBD vs those without IBD more frequently resulted in preterm birth (8.0% vs
5.5%, aOR 1.51; 95% CI: 1.45-1.58), small for gestational age birth (11.1% vs 9.8%,
aOR 1.15; 95% CI: 1.10-1.20) and caesarean section (26.1% vs 20.0%, aOR 1.39;
95% CI: 1.35-1.42). Active IBD before and during pregnancy was associated with
particularly marked increases in the rates of prematurity and small for gestational
age as compared to non-IBD pregnancies. Active IBD during pregnancy was associated
with more stillbirths than non-IBD pregnancies (aOR 1.43 95% CI: 1.09-1.86).
Crohn’s disease activity decreased during pregnancy, while ulcerative colitis activity
did not change.

Pregnancies in women with IBD are associated with increased risks
of prematurity, small for gestational age and caesarean section, especially among
women with active IBD. Disease activity decreased during pregnancy in women with
Crohn’s disease, but was unchanged in women with ulcerative colitis.