Fetal–neonatal and maternal pregnancy outcomes in women with rheumatoid arthritis: a population-based cohort study

Objectives Rheumatoid arthritis (RA) may adversely influence pregnancy and lead to adverse birth outcomes. This study estimated the risk of adverse fetal–neonatal and maternal pregnancy outcomes in women with RA.Design This was a retrospective cohort study.Setting We used both the National Health Insurance database and the Taiwan Birth Reporting System, between 2004 and 2014.Participants We identified 2 100 143 singleton pregnancies with 922 RA pregnancies, either live births or stillbirths, delivered by 1 468 318 women.Outcome measures ORs with 95% CIs for fetal–neonatal and maternal outcomes were compared between pregnancies involving mothers with and without RA using an adjusted generalised estimating equation model.Results Covariates including age, infant sex, Charlson Comorbidity Index, urbanisation, income, occupation, birth year and maternal nationality were adjusted. Compared with pregnancies in women without RA, pregnancies in women with RA showed that the fetuses/neonates had adjusted ORs (95% CI) of 2.03 (1.66 to 2.50) for low birth weight (n=123), 1.99 (1.64 to 2.40) for prematurity (n=141), 1.77 (1.46 to 2.15) for small for gestational age (n=144) and 1.35 (1.03 to 1.78) for fetal distress (n=60). Pregnancies in women with RA had adjusted ORs (95% CI) of 1.24 (1.00 to 1.52) for antepartum haemorrhage (n=106), 1.32 (1.15 to 1.51) for caesarean delivery (n=398), and 3.33 (1.07 to 10.34) for disseminated intravascular coagulation (n=3), compared with women without RA. Fetuses/neonates born to mothers with RA did not have a higher risk of being stillborn or having fetal abnormalities. Pregnant women with RA did not have increased risks of postpartum death, cardiovascular complications, surgical complications or systemic organ dysfunction.Conclusions Pregnancies in women with RA were associated with higher risks of multiple adverse fetal–neonatal and maternal outcomes; however, most pregnancies in these women were successful.