The ratio between IFN-γ and IL-10 serum levels (IFN-γ/IL-10) was higher in healthy women compared to SLE patients in both the first (median 1.88, range 1.30 to 3.67, vs 0.97, range 0.44 to 1.93, P = 0.001) and the third trimester of pregnancy (median 2.00, range 0.90 to 3.10, vs 0.83, range 0.35 to 1.48, P = 0.001). The gene discussed is IFNG; the disease is systemic lupus erythematosus.