A systematic review and meta-analysis of pregnancy outcomes in patients with systemic lupus erythematosus and lupus nephritis

Background and objectives: Studies of the impact of systemic lupus erythematosus (SLE) and its pregnancy complications have yielded conflicting results. Major limitations of these studies relate to their small numbers of patients and retrospective designs. The aim of this study was to perform a systematic literature review of pregnancy outcomes in women with SLE and a meta-analysis of the association of lupus nephritis with adverse pregnancy outcomes. Design, setting, participants, & measurements: We searched electronic databases from 1980 to 2009 and reviewed papers with validity criteria. Random-effects analytical methods were used to evaluate pregnancy complications rates. Results: Thirty-seven studies with 1842 patients and 2751 pregnancies were included. Maternal complications included lupus flare (25.6%), hypertension (16.3%), nephritis (16.1%), pre-eclampsia (7.6%), and eclampsia (0.8%). The induced abortion rate was 5.9%, and when excluded, fetal complications included spontaneous abortion (16.0%), stillbirth (3.6%), neonatal deaths (2.5%), and intrauterine growth retardation (12.7%). The unsuccessful pregnancy rate was 23.4%, and the premature birth rate was 39.4%. Meta-regression analysis showed statistically significant positive associations between premature birth rate and active nephritis and increased hypertension rates in subjects with active nephritis or a history of nephritis. History of nephritis was also associated with pre-eclampsia. Anti-phospholipid antibodies were associated with hypertension, premature birth, and an increased rate of induced abortion. Conclusions: In patients with SLE, both lupus nephritis and anti-phospholipid antibodies increase the risks for maternal hypertension and premature births. The presented evidence further supports timing of pregnancy relative to SLE activity and multispecialty care of these patients.