Pregnancy outcomes in women with rheumatoid arthritis: a retrospective population-based cohort study.

To assess if pregnancies in women with rheumatoid arthritis (RA) are at a higher risk for adverse maternal and neonatal outcomes. A retrospective cohort study was carried out using the Healthcare Cost and Utilization Project - National Inpatient Sample (HCUP-NIS) from the USA. All births that took place from 2004 to 2013 were identified and women were classified as having RA or not on the basis of ICD-9 coding. Unconditional logistic regression was used to evaluate the adjusted effect of RA on maternal and neonatal outcomes. Of the total 8,417,607 births in our cohort, 6068 were among women with RA for an overall prevalence of 72 per 100,000 births. There was a steady increase in reported RA in pregnancy from 47 to 100 per 100,000 over the 10-year study period. Compared with women without RA, women with RA were more likely to develop pre-eclampsia/eclampsia, gestational diabetes, to present with preterm premature rupture of membranes(PPROM), to experience placental abruption and placenta previa, and to deliver by caesarean section. Postpartum, RA-complicated pregnancies were associated with wound complications and thromboembolisms. Congenital anomalies, small for gestational age and preterm birth were more common in neonates of women with RA. RA in pregnancy is associated with a greater likelihood of adverse maternal and neonatal outcomes. Women with RA should be made aware of these risks and be followed as a high risk pregnancy.