Pregnancy outcome for women with Crohn's disease: a follow-up study based on linkage between national registries

OBJECTIVE: Crohn's disease, characterized by chronic intestinal inflammation, is sometimes followed by malabsorption, which may interfere with embryogenesis and fetal growth. Therefore we examined birthweight, the frequency of preterm birth, and other reproductive outcomes in the offspring of women with Crohn's disease.

METHODS: We used a historical registry-based study, with linkage between the Danish National Registry of Patients and the Danish Medical Birth Registry. Included were 510 newborns to mothers with Crohn's disease and 3018 controls in the study period from 1982 to 1992.

RESULTS: The average birthweight of newborns to mothers with Crohn's disease was 185 g, 134 g less than expected for primiparas and multiparas. After adjusting for potential confounders the differences were 142 g (95% confidence interval [CI95%] = 76, 208) and 105 g (CI95% = 37, 173), respectively. The risk of low birthweight was increased in Crohn patients (odds ratio [OR] = 2.4; CI95% = 1.6-3.7), as was the risk of preterm birth (OR = 1.6; CI95% = 1.1-2.3).

CONCLUSION: We found a lower birthweight in newborns of patients with Crohn's disease, indicating that Crohn's disease or its treatment may influence fetal growth.