Several studies have emphasized poor pregnancy outcomes associated with active lupus nephritis at the onset of conception. A few controversial studies have compared pregnancy outcome in patients with inactive lupus nephritis at conception and those without a history of lupus nephritis. This study aimed to find out if quiescent lupus nephritis at the onset of conception carries an increased risk of pregnancy complications compared to pregnancies without a history of lupus nephritis. This is a prospective cohort study carried out at the Rheumatology/Obstetrics Conjoint Clinic of Kasr Al-Ainy Hospital between January 2006 and December 2017. A total of 119 pregnancies were included: 72 pregnancies in group I (with a history of lupus nephritis) and 47 pregnancies in group II (non-renal systemic lupus erythematosus). They were subjected to full history taking, monthly clinical examination and laboratory investigations. In total, 16 (22.2%) renal pregnancies had renal flares at the onset of conception. Maternal complications, specifically renal flares, were reported in 36 (50%) pregnancies in group I and 13 (27.7) pregnancies in group II, with a significant difference (p = 0.015). No significant differences were found concerning the frequency of pregnancy-related maternal and fetal complications between the two groups. When data were re-analyzed after excluding patients experiencing renal flares during the 6 months preceding pregnancy, there were no significant differences regarding the frequency of maternal and fetal complications between renal and non-renal pregnancies. In conclusion, lupus nephritis, per se, is not a risk factor for poor pregnancy outcome; rather, it is the lupus nephritis activity at the onset of pregnancy.
Keywords: Systemic lupus erythematosus; fetal complications; lupus nephritis; maternal complications; pregnancy outcome.