C3 and lupus nephritis: We also created a predictive model based on linear discriminant analysis, which indicated that SLEDAI-2k score ≥4 from the first trimester, maternal body mass index, use of aspirin, proteinuria present in the third trimester, low complement (C3) in the first and second trimesters, decreased cerebroplacental ratio in the second trimester, personal history of lupus nephritis, hepatic cytolysis, and increased uric acid weighted the most in the model classification process.