Associations between inflammatory bowel disease, medication use and rates of pre-eclampsia in the Danish National Birth Cohort, 1996–2003

HR, hazard ratio; CI, confidence interval.

All estimates were adjusted for parity (0, 1, ≥2), socioeconomic status (6 categories: master’s degree or higher and currently employed, or leader of a business with ≥10 employees; bachelor’s degree and currently employed, or leader of a business with <10 employees; skilled worker (completed vocational training with apprenticeship) and currently employed; unskilled worker or unemployed (short-term); current student; unemployed (long-term)), pre-pregnancy BMI (<20, 20–25, >25), and smoking (non-smoker, smoker) and alcohol consumption (non-drinker, <1 drink/week, ≥1 drink/week) during pregnancy, in strata within the models.

a ICD-10 codes O14.0-O15.9 registered in the Hospital Discharge Register.

b ICD-10 codes O14.1, O14.2 or O15.0–15.9 registered in the Hospital Discharge Register.

c ICD-10 codes O14.1, O14.2 or O15.0–15.9 registered in the Hospital Discharge Register before 34 weeks’ gestation.

d Includes women with IBD who used internal corticosteroids or 5-ASA during pregnancy, as well as women who used no medication.

e When we modelled the effect of IBD type and medication use on the rate of severe, early pre-eclampsia with the covariates in strata, the models did not converge. Consequently, the estimates presented here were adjusted for the potential confounders through inclusion of the covariates as independent variables in the model.

Associations between inflammatory bowel disease, medication use and rates of pre-eclampsia in the Danish National Birth Cohort, 1996–2003