Impact of perinatal factors on growth deficits of preterm infants.

OBJECTIVE

To review perinatal factors associated with a growth deficit in preterm infants at a corrected age of one year.

METHODS

Cohort study of preterm infants with a birth weight < 2,000 g. Percentiles and Z scores of body weight (W/A), length (L/A) and head circumference (HC/A) at one year of corrected age were calculated by using the Centers for Disease Control and Prevention curves.

RESULTS

Among 303 preterm infants, the frequencies of measures below the 10th percentile (P10) and Z scores -2 were 43.2% and 24.4% for W/A, 22.1% and 8.6% for L/A and 15.8% and 4.6% for HC/A, respectively. Logistic regression analyses showed factors associated with higher odds for W/A < P10 were resuscitation at birth (1.8 times) and small for gestational age infants (3.0 times). In infants rated as small at full-term postconceptual age, the odds for W/A < P10 were 4.0 times as high in those with a birth weight between 1,000 and 1,499 g and 3.5 times as high in those > 1,500 g. As birth length was reduced, the odds for L/A < P10 increased, but this was not associated with birth weight. The odds for HC/A < P10 were 2.5 times as high in small for gestational age infants. In infants with a body weight < 1,000 g, the odds for HC/A < P10 were 4.4 times higher, compared with those between 1,000 g and 1,499 g and 5.3 times higher if compared with those > 1,500 g.

CONCLUSION

At a corrected age of one year, preterm infants with a birth weight < 2,000 g were found with high growth deficits frequencies, and associated factors were variable, depending on the analyzed deficit, with intrauterine and postnatal growth restriction being outstanding predictors.