Purpose: To assess if pregnancies in women with rheumatoid arthritis (RA) are at a higher risk for adverse maternal and neonatal outcomes.Materials and methods: 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.Results: 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.Conclusion: 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.