Not only disease activity but also chronic hypertension and overweight are determinants of pregnancy outcomes in patients with systemic lupus erythematosus

Introduction Pregnancies in women with lupus nephritis are at high-risk of complications, while scarcity of scientific knowledge on prognostic factors impedes a fair medical counseling. We aimed to identify determinants associated with maternal and fetal complications. Materials We retrospectively reviewed medical charts of pregnancies that lasted more than 22 weeks in 66 patients with pre-existing lupus nephritis between 2004 and 2013 in France. Univariate and multivariate analyses were conducted to identify determinants for maternal complications, lupus renal flare and fetal prematurity or death. Results Eighty-four pregnancies were identified. A maternal complication occurred in 31 pregnancies (36.9%): mostly preeclampsia (17 pregnancies, 20.2%) and renal flares (12 pregnancies, 14.3%). Overall fetal survival was 94.0% (79/84). Maternal pregnancy complications were independently associated with prepregnancy body mass index >25 kg/m2 (OR 3.81, 95% CI 1.03–14.09) and immunological activity (positive anti-dsDNA antibodies or Farr assay lupus) (OR 4.95, 95% CI 1.33–18.43). Renal lupus flares were independently associated with maternal age (OR 1.50, 95% CI 1.12–2.01) and prepregnancy immunological activity (OR 15.99, 95% CI 1.57–162.68) while a remission time >12 months had a protective effect (OR 0.17, 95% CI 0.04–0.68). Three parameters were associated with a higher risk of fetal prematurity or death: a prepregnancy body mass index >25 kg/m2 (HR 3.58, 95% CI 1.45–8.83), hypertension (HR 8.97, 95% CI 3.32–24.25), and immunological activity (HR 3.34, 95% CI 1.30–8.63). Conclusion Maternal age, prepregnancy hypertension, body mass index >25 kg/m2 and lupus immunological activity may be considered as the main determinants for fetal and maternal complications. A remission time above 12 months for patients with lupus nephritis could be associated with a reduced risk of renal flare during pregnancy.