Rheumatoid arthritis (RA) is a common chronic systemic autoimmune disease affecting women of childbearing age. We aimed to conduct a meta-analysis of published observational studies to systematically evaluate the association between RA and adverse pregnancy outcomes. Medline (PubMed), EMBASE, and Web of Science were searched for keywords from the date of inception to December 28, 2021, to identify relevant studies reporting adverse maternal and/or fetal outcomes in RA pregnancies. Data from individual studies were pooled using random-effects models and presented as odds ratios (ORs) with 95% confidence intervals (CIs). Eighteen studies with a total number of over 50 million participants were eligible for inclusion. This current analysis showed that in pregnant women with RA, there was a significantly increased risk of adverse maternal outcomes, including caesarean section (OR, 1.39; 95% CI 1.24-1.55), pre-eclampsia (OR, 1.48; 95% CI 1.19-1.83), gestational hypertension (OR, 1.34; 95% CI 1.07-1.68) and spontaneous abortion (OR, 1.16; 95% CI 1.04-1.29). Similarly, maternal RA during pregnancy was also associated with a significantly increased risk of adverse fetal outcomes, including preterm birth (OR, 1.58; 95% CI 1.44-1.74), small for gestational age (OR, 1.49; 95% CI 1.22-1.82), low birth weight (OR, 1.45; 95% CI 1.30-1.63), congenital anomalies (OR, 1.36; 95% CI 1.01-1.83) and stillborn (OR, 1.38; 95% CI 1.09-1.74). Maternal RA is significantly associated with an increased risk of adverse maternal and fetal outcomes. Close monitoring of the clinical status of RA patients before and during pregnancy is essential in clinical practice. Key Points • Pregnant women with rheumatoid arthritis (RA) are at significantly increased risk for adverse maternal and fetal outcomes. • The increased risk of adverse pregnancy outcomes in women with RA may be closely related to medication use and disease activity. • Close monitoring of the clinical status of RA patients before and during pregnancy is essential in clinical practice.