Chronic hypertension among pregnant women with stage 3-5 chronic kidney disease (CKD) is the strongest predictor of preterm delivery of infants prior to 34 weeks’ gestation, according to a new study.
In a retrospective cohort study of 178 pregnancies in 159 women with stage 3-5 CKD, gestation, Kate Wiles, MBBS, of the Department of Women and Children’s Health, Kings College, London, UK, and colleagues found that incidence of delivery prior to 34 weeks was 32% among women with chronic hypertension compared with 0% of normotensive women. The risk of delivery prior to 34 weeks among women with chronic hypertension was 20% among women with a greater than 10% gestational decrease in serum creatinine from pre-pregnancy values compared with 40% among women a less than 10% decrease, the investigators reported in Nephrology Dialysis Transplantation.
Women with a urinary protein-creatinine ratio greater than 100 mg/mmol prior to pregnancy or before 20 weeks’ gestation had approximately 2.6-fold increased odds of infant birthweight below the 10th centile.
In addition, the investigators observed a mean 4.5 mL/min/1.73 m2 decline in estimated glomerular filtration rate (eGFR) between pre-pregnancy and post-partum values, which was greater than the mean 1.8 mL/min/1.73 m2/yr annual decline in eGFR prior to pregnancy. At 1 year post-partum, 46% of women had lost at least 25% of their pre-pregnancy eGFR or required renal replacement therapy, according to the investigators. The post-partum eGFR decline was equivalent to 2.5 years of pre-pregnancy CKD, Dr Wiles and colleagues reported.
The new findings can be used to inform pre-pregnancy counseling, antenatal surveillance, and the postnatal management of women with stage 3-5 CKD, including appropriate preparation for dialysis and transplantation in the post-partum period,
Of the 159 women, 79% had chronic hypertension. The live birth rate was 98%, and 26% of infants were delivered prior to 34 weeks’ duration.
Wiles K, Webster P, Seed PT, et al. The impact of chronic kidney disease stages 3-5 on pregnancy outcomes. Published online December 12, 2020. Nephrol Dial Transplant. doi:10.1093/ndt/gfaa247