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.
Keywords: Lupus nephritis; chronic kidney disease; pregnancy.