Maternal and Perinatal Outcomes in Pregnancy by Chronic Kidney Disease Stage Based on Midterm Glomerular Filtration Rate

Abstract

Objective: Chronic kidney disease (CKD) is a known risk factor of pregnancy that increases the rates of preterm birth, intrauterine growth restriction, and preeclampsia. And maternal CKD may worsen due to pregnancy itself. However, few studies have examined these problems in Korea. Methods: The cases of 29 women with CKD who delivered singleton at our institute between 2006 and 2018 were retrospectively reviewed. Cases with major fetal malformation, intrauterine fetal death, a history of kidney transplantation, or insufficient information for the parameters were excluded. The subjects were divided into early-stage (stages 1 and 2) and late-stage (stages 3 to 5) groups according to the midterm glomerular filtration rate (GFR). Demographic profiles, renal function, perinatal complications, and changes in GFR from pre-conception to postpartum were compared and analysed. Results: The incidence of preeclampsia (28.6% vs. 75.0%; P=0.038), anemia (28.6% vs. 75.0%; P=0.038), cesarean section (42.9% vs. 100.0%; P=0.009), small for gestational age (14.3% vs. 62.5%; P=0.019) and the need for neonatal intensive care unit (38.1% vs. 87.5%, P=0.035) were significantly higher in the late-stage group than those in the early-stage group. Gestational age at delivery (38.1 vs. 35.4 weeks, P=0.021) and birth weight (2,970 vs. 2,200 g, P=0.006) were significantly lower in the late-stage group than those in the early-stage group. GFR decreased significantly after delivery compared to pre-conception in both group (P=0.028, both). Conclusion: Late-stage CKD is a poor prognostic factor for pregnancy outcomes. Pregnancy deteriorates renal function even in early-stage. Close monitoring and management are required for pregnant women with any stage of CKD.