Pregnancy Outcomes and Long-Term Kidney Function in Women with Primary Glomerulonephritis

Abstract Background Whether pregnancy accelerates long-term kidney function decline in women with primary glomerulonephritis remains unclear. This study aimed to evaluate maternal and fetal outcomes and the long-term course of kidney function in women with primary glomerulonephritis. Methods This retrospective single-center study analyzed 40 pregnancies in 31 women with biopsy-proven primary glomerulonephritis (1996–2022). A control group of nulliparous women with primary glomerulonephritis, matched for subtype, age at diagnosis, and disease duration, was included. Obstetric and neonatal outcomes were evaluated alongside longitudinal kidney parameters assessed before, during, and up to 60 months postpartum. Results Common diagnoses were focal segmental glomerulosclerosis (32.3%) and IgA nephropathy (25.8%). Mean maternal age was 29.6±4.1 years. Preeclampsia occurred in 15% and preterm birth in 50% of pregnancies (mean birth weight: 2819±859 g). During pregnancy, serum creatinine decreased and eGFR increased (p<0.001). Postpartum, serum creatinine returned to baseline, showing no significant differences at 6, 12, or 60 months. Although eGFR at 60 months was lower than pre-pregnancy levels, serum creatinine remained comparable to baseline and no significant differences in kidney function parameters were observed between the pregnancy and control groups at 60 months. The clinical significance of the isolated reduction in calculated eGFR therefore remains uncertain. Conclusions In women with primary glomerulonephritis and predominantly early-stage kidney disease, physiological kidney adaptation during pregnancy is largely preserved. No clear acceleration in long-term kidney function decline was observed compared with matched controls; however, an adverse effect of pregnancy cannot be excluded. Preeclampsia and preterm delivery remain significant, requiring monitoring.