Secular trends of pregnancies in women with inflammatory connective tissue disease

INTRODUCTION: This study examined secular trends in reproductive outcome in women with inflammatory connective tissue disease compared with reference deliveries from the general population. MATERIAL AND METHODS: Historical cohort study based on data registered in the Medical Birth Register of Norway from 1967 to 2009. The study included singleton births in women recorded with connective tissue disease (n = 851) and reference deliveries from the general population (n = 2 437 110). Births were stratified in four periods, 1967-1979, 1980-1989, 1990-1999 and 2000-2009. Associations between connective tissue disease and maternal and perinatal outcomes by decade were assessed in logistic regression analyses and adjusted for maternal age at delivery and parity. RESULTS: In the 1970s, around 2.7 deliveries/year were registered for women with connective tissue disease (0.004% of all deliveries). This increased to 42 deliveries/year (0.07% of all deliveries) after 2000. Adjusted odds ratios (aOR) for cesarean section were 5.0 (95% CI 2.1-11.9) in the first and 1.8 (95% CI 1.4-2.3) in the last period. For preterm delivery the aOR decreased from 4.9 (95% CI 2.1-11.4) to 3.1 (95% CI 2.3-4.2) and the aOR for birthweight <2500 g changed from 7.3 (95% CI 3.3-16.3) to 4.1 (95% CI 3.0-5.6). CONCLUSIONS: An increasing number of births were observed over time among women with connective tissue disease. Adverse pregnancy outcomes were more common among women with connective tissue disease but risks have decreased over time.