Objective To completely and quantifiably determine the effect of systemic lupus erythematosus (SLE) on pregnancy outcomes in a Chinese cohort. Design A retrospective cohort study. Setting Data were collected at a tertiary medical centre located in Shanghai, China, from September 2011 to May 2017. Participants We assigned 338 pregnant women with SLE to the study cohort and 1014 randomly selected pregnant women without SLE (three for every woman with SLE) to a comparison cohort. The relevant medical records of all pregnant women were retrospectively reviewed. Cases of multiple pregnancy and cases in which an artificial abortion was performed for personal reasons were excluded. Primary and secondary outcome measures Maternal and fetal outcomes were primary outcomes, and management of antenatal care was the secondary outcome. Results The risks of pregnancy-induced hypertension (OR 2.68, 95% CI 1.75 to 4.09), pre-eclampsia (OR 3.13, 95% CI 1.95 to 5.03) and premature rupture of membranes (OR 2.53, 95% CI 1.46 to 4.40) were significantly different between women with and without SLE. Gestational diabetes was negatively associated with SLE in pregnant women (OR 0.49, 95% CI 0.28 to 0.85). Pregnant women with SLE displayed significantly higher rates of fetal loss (OR 10.23, 95% CI 5.08 to 20.59), including spontaneous abortion (OR 4.42, 95% CI 1.52 to 12.80), therapeutic abortion (OR 16.57, 95% CI 5.80 to 47.35) and stillbirth (OR 13.25, 95% CI 1.49 to 118.11), and a higher risk of preterm birth (OR 3.15, 95% CI 2.21 to 4.50), intrauterine growth restriction (OR 2.20, 95% CI 1.35 to 3.58), a child who was small for the gestational age (OR 1.86, 95% CI 1.11 to 3.13), a caesarean section (OR 4.73, 95% CI 3.30 to 6.80) or a neonatal intensive care unit admission (OR 3.48, 95% CI 2.21 to 5.48) than women in the non-SLE population after adjusting for confounding factors. Conclusions In this study, SLE significantly increased the risk of adverse pregnancy outcomes. Therefore, a preconception assessment and close antenatal monitoring by both rheumatologists and obstetricians should be performed in pregnant women with SLE.