Effect of Pregnancy and Delivery on the Renal Function and the Prognosis of Patients with Chronic Kidney Disease Stage 3 Caused by Immunoglobulin A Nephropathy

Immunoglobulin A nephropathy (IgAN) exhibits a peak onset that coincides with the reproductive age. Therefore, many young women with IgAN may become pregnant. However, the outcome of pregnancy in women with renal diseases remains controversial, and the characteristics and outcome of pregnancy in IgAN patients must be further evaluated.A prospective follow-up study of 64 pregnant women with IgAN was performed by analyzing the laboratory data and prognosis. To clarify the influence of renal insufficiency, we compared these patients according to the chronic kidney disease (CKD) stage with special attention to CKD stage 3 [N=16 in total, N=9 for estimated glomerular filtration rate (eGFR) ≥45 mL/min, N=7 for <45 mL/min].We found that pregnancy and delivery did not produce any significant changes in the renal function for patients with CKD stage 3 (≥45 mL/min) at five years after delivery, although proteinuria was elevated at 30 weeks of pregnancy and at three months after delivery. However, only for patients with CKD stage 3 (<45 mL/min) was there a significant deterioration in the eGFR at five years after delivery. Additionally, the data of pregnant women with CKD stage 3 were compared with those of 22 nonpregnant women with similar clinical and demographic characteristics.Pregnant patients with IgAN (CKD stage 3, eGFR ≥45 mL/min) did not exhibit any significant reduction in the renal function at five years after delivery as compared with the baseline, which was similar to the findings in nonpregnant patients. Thus, while pregnancy with CKD stage 3 (eGFR ≥45 mL/min) was not a risk factor, patients with CKD stage 3 (eGFR <45 mL/min) showed a worsened renal function five years after delivery.