Renal Function in Early Childhood in Very Low Birthweight Infants

ABSTRACT

We evaluated renal function in early childhood in 48 very low birthweight (VLBW) ex-preterms and correlated the perinatal risk factors for acute renal failure (ARF) and postnatal growth course to abnormal renal findings at children-age. Nineteen boys and 29 girls (6.3 to 8.2 years of age) had a physical examination, exploration of renal function, and ultrasound. Cases were compared with age-matched controls that were born full term. All patients had normal blood pressure, renal ultrasound, and kidney length to body height. Plasma creatinine and clearance were normal, and no differences were observed with controls. No correlation was found between childhood renal parameters and perinatal variables. Versus controls, 8.3% had pathological microalbuminuria (ACR > 20 mg/g; p = 0.19). Analysis of risk factors for ARF showed that hypotension during neonatal life had a significant independent association with ACR > 20 mg/g at children-age (p = 0.009). Microalbumin excretion and ACR > 20 mg/g strongly correlated with weight z score at 12 months (R, 0.48; 0.21 < R < 0.68) and weight catch-up growth at 6 months (R, 0.38; 0.09 < R < 0.61) and 12 months (R, 0.56; 0.32 < R < 0.74) of corrected age. In conclusion, in VLBW infants, acute conditions such as hypotension and early catch-up growth correlate in childhood to subtle changes in renal function, which can provide early information about the risk of kidney disease in this population.

KEYWORDS

Preterm - renal follow-up - hyperfiltration - microalbuminuria - catch-up growth - weight z score

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