Risk of congenital malformation in newborns from mothers with kidney diseases in a nationwide cohort study

Background: Maternal chronic kidney disease (CKD) is associated with an increased risk of adverse pregnancy outcomes. However, the overall risk of congenital malformations (CMs) in offspring of mothers with kidney disease, including CKD and end-stage kidney disease (ESKD), remains unclear. Methods: In this nationwide cohort study, we analyzed National Health Insurance Service (NHIS) data from 2,680,092 women who gave birth between 2008 and 2017. Major CMs were identified using the International Classification of Diseases-10 (ICD-10) codes during the first 12 months after birth. A multivariable generalized estimating equation model was used to compare the risk of CMs between women with CKD or ESKD, including those on dialysis and post-kidney transplantation (KT), and healthy controls. Results: Major CMs prevalence is 4.79% in offspring of healthy mothers, 5.29% in CKD mothers, and 9.65% in ESKD mothers, with congenital heart defects being the most common anomaly across all groups. After adjustment, mothers with kidney diseases show a higher risk of major CMs than healthy controls (adjusted odds ratio [aOR], 1.07; 95% confidence interval [CI], 1.03–1.11 in CKD; aOR, 1.71; 95% CI, 1.16–2.52 in ESKD, respectively). Among ESKD patients, KT recipients show an increased risk (aOR, 1.65; 95% CI, 1.06–2.59), but dialysis patients do not reach statistical significance (aOR, 2.02; 95% CI, 0.92–4.41). Conclusions: Our findings suggest that neonates born to mothers with kidney diseases have an increased risk of CMs compared to those born to healthy mothers.