Children with low birth weight have a higher rate of reduced kidney function than previously reported

Previously reported descriptions of the risks associated with low birth weight (LBW) may have underestimated the potential for reduced kidney function and hypertension in affected children, according to a study.

In this cross-sectional study, 6336 children between the ages of 12 and 15 years over 13 million US individuals were evaluated to determine an association with birth weight and kidney disease. Low birth weight, very low birth weight (VLBW), and large birth weight (BW) were defined as (< 2500 g), (< 1500 g), and (> 4000 g), respectively. Blood pressure (BP) was also assessed using pediatric hypertension guidelines.

With the updated Schwartz formula, children born with low birth weight (LBW) have a 30.1% prevalence of reduced kidney function, while children with normal birth weight (BW) have a prevalence of 22.4%. Different equations resulted in varying estimates of reduced kidney function prevalence in LBW individuals, ranging from 21.5% for Counahan-Barratt to 35.4% for CKiD-U25. In comparison to those with normal BW, participants with LBW and very low birth weight (VLBW) had a 7.2% and 10.3% higher prevalence of elevated blood pressure (BP), and a 2.4% and 14.6% higher prevalence of hypertension, respectively.

Reference
Brathwaite KE, Levy RV, Sarathy H, et al. Reduced kidney function and hypertension in adolescents with low birth weight, NHANES 1999-2016. Pediatr Nephrol. 2023;doi: 10.1007/s00467-023-05958-2. Epub ahead of print. PMID: 37052695.