Postnatal Steroid Exposure in Extremely Low Gestational Age Newborns and Kidney Function at 24 Months Corrected Age

Area of Science:

• Neonatal Medicine
• Pediatric Nephrology
• Pharmacology

Background:

• Preterm birth is linked to lower nephron endowment and increased risk of chronic kidney disease (CKD).
• Antenatal corticosteroids (ANS) are standard for lung maturity in preterm neonates.
• The impact of postnatal corticosteroids on kidney function remains largely unknown.

Purpose of the Study:

• To investigate the influence of postnatal corticosteroid timing and duration on kidney function in preterm infants at 24 months corrected age.
• To assess the association between different postnatal corticosteroid regimens and estimated glomerular filtration rate (eGFR).

Main Methods:

• Secondary analysis of the PENUT trial data from neonates born <28 weeks' gestation.
• Included surviving infants with serum creatinine measured at 22-26 months corrected gestational age (cGA).
• Evaluated exposure to postnatal steroids (type, start date, duration) and primary outcome of reduced eGFR (<90 mL/min/1.73 m²).

Main Results:

• Out of 348 infants evaluated, 61 (17.5%) had reduced GFR.
• Hydrocortisone use for 1-7 days was associated with 2.8 times increased odds of reduced GFR.
• Early dexamethasone initiation (≤25 weeks postmenstrual age) showed 9.39 times increased odds of reduced GFR compared to later initiation (≥29 weeks PMA).

Conclusions:

• Observational data suggest an association between postnatal corticosteroid timing, duration, and reduced kidney function (GFR) in preterm infants.
• Further research is needed to elucidate these associations and inform strategies to protect long-term kidney health in this vulnerable population.