N ΓΈrgΓ₯rd et al conducted a population-based cohort study using the Danish National Registry of Patients and Denmark's National Birth Registry to examine the association between Crohn's disease (CD) activity during pregnancy and the risk of adverse birth outcomes. It is a unique study that addresses an important issue concerning our many patients of child-bearing age. They explored not only the impact of disease activity on birth outcomes, but also the effect of concomitant drug use during pregnancy.
The study covered all live-born children born to women with CD in North Jutland County, Denmark, since 1977. They analyzed 157 births by 108 women with CD. The authors thoroughly reviewed the medical records with stringent criteria defining CD and activity of disease in each trimester. The main study outcomes were low birthweight (Ο½2500 g), low birthweight at term (Ο½2500 g and Υ37 weeks gestation), preterm birth (Ο½37 weeks gestation), and congenital anomalies. The analysis was restricted to singleton births and every pregnancy was analyzed as an independent event. These outcomes were adjusted for maternal drug use, calendar period, duration of CD, gestational age, maternal age, parity, and smoking in the final model.
Almost half (45.2%) of the mothers had low or moderate-to-high disease activity at some point during their pregnancy and were compared to women with inactive disease (54.8%). Age, parity, and disease location were comparable in the 2 groups. Women with low activity were mainly treated with 5-aminosalicylate (5-ASA) drugs. Those with moderate to severe disease activity were treated with 5-ASA and steroids, and only rarely with immunomodulators. There were more smokers in the inactive disease cohort (48.8%!).
Birthweights were identical in the 2 groups and the mean gestational age was marginally shorter in women with disease activity. The relative risk of preterm birth was 2-fold higher among women with active disease and correlated with severity of disease activity. There were 8 children with congenital anomalies, 3 in the active disease group, and 5 in the inactive group.