Collagen cross-links and early postnatal growth in newborns with intrauterine growth retardation

Abstract

This study assessed growth and skeletal metabolism in full-term newborns with intrauterine growth retardation (IUGR) and determined the value of the urinary excretion of collagen cross-links in predicting postnatal catch-up growth. We studied 38 newborns (16 females) born at term with a birth weight less than the 10th centile of the reference and a ponderal index ([PI] 100 × weight in g/length in cm3) of 2.27 ± 0.19. The sample was divided into 23 children with proportionate ([P] PI ≥ 10th centile of the reference) and 15 with nonproportionate ([NP] PI < 10th centile of the reference) IUGR. The weight, head circumference, length, and knee-heel length of the newborns at days 7, 14, 30, 60, and 90 were measured. The height of 23 of the 38 children was also assessed at 27 ± 6 months of life. Urinary collagen cross-links were analyzed by high-performance liquid chromatography at day 14 and day 60. Most of the infants (68%) underwent catch-up growth, and the growth performance at 3 months was independent of the proportions at birth. Children who did not show catch-up growth in the first trimester of life failed to normalize in height in the following 2 years. The urinary excretion of pyridinoline (Pyd) was not related to the anthropometric measurements. In P children, urinary excretion of deoxypiridinoline (Dpd) at day 14 significantly correlated with the gain in length during the first 3 months, accounting for 25% of the variance. In NP children, these correlations between urinary Dpd and the gain in length were not significant. The evaluation of urinary Dpd excretion at 2 weeks of age might help to determine the therapeutic regimen in IUGR children. Copyright © 2000 by W.B. Saunders Company