Catch-up growth in very-low-birth-weight infants. Clinical correlates.

Clinical correlates of catch-up growth were documented in 182 very-low-birth-weight (VLBW) infants (less than 1.5 kg) followed up prospectively until a corrected age of 33 months. At birth, 147 infants had weights appropriate for gestational age (AGA), and 35 were small for gestational age (SGA). The infants in each group were categorized as small if body weight was 2 SDs below the mean for age or appropriate if body weight was within 2 SDs of the mean at birth and at corrected ages of 40 weeks and 8, 21, and 33 months. Of the 147 AGA infants, 67 (46%) weighed less than 2 SDs of the mean for age at a corrected age of 40 weeks, 40 (27%) at 8 months, 28 (19%) at 21 months, and 25 (17%) at 33 months. Of the 35 SGA infants, 32 (91%) had subnormal weight at 40 weeks, 17 (49%) at 8 months and 21 months, and 16 (46%) at 33 months. Significant correlates of poor catch-up growth in the AGA group were birth weight, gestational age, severity of neonatal complications, poor neonatal head growth, and chronic physical and neurologic sequelae. In the infants in the SGA group, the correlates of poor catch-up growth were birth weight, multiple birth, and social class.