In newborns, renal glomerular filtration is what percent of an adult's?

• A. They have 80%
• B. They have 100%
• C. They have 20%
• D. They have 50%

Answer: (C)

Renal maturation limits filtration capacity in newborns, so their glomerular filtration rate is much lower than an adult’s. At birth, GFR is about 20% of the adult value, reflecting immature nephrons and renal blood flow. This reduced filtration affects how quickly substances cleared by the kidneys are eliminated in neonates, which is why drug dosing and fluid management must account for limited renal clearance. As children grow, GFR increases toward adult levels over the first year and beyond, so the neonatal value of roughly one-fifth of an adult best captures the typical GFR at that stage.