Heterogeneous Growth and Mental Development of Intrauterine Growth-Retarded Infants During the First 3 Years of Life

TLDR

The study followed 205 term infants, including two intrauterine growth‑retardation subgroups (low and adequate ponderal index) and a normal birth‑weight group, to assess postnatal growth and development up to 3 years. IUGR infants with adequate ponderal index remained lighter, shorter, and had poorer developmental scores through 3 years, whereas those with low ponderal index showed catch‑up weight gain but still lagged behind normal‑weight peers, indicating that birth physical characteristics predict postnatal growth and development.

Abstract

Postnatal growth and development were studied in two groups of term infants with intrauterine growth retardation (IUGR) and one group of infants with normal birth weight up to 3 years of age (total sample, 205 infants). Infants with IUGR were classified as having low ponderal index (IUGR-LPI) or adequate ponderal index (IUGR-API). At birth, the two groups of infants with IUGR had similar birth weight, but length and head circumference measurements were significantly different. Overall, the IUGR-API infants remained lighter and shorter and had smaller head circumferences up to 30 months of age. The IUGR-LPI infants experienced catch-up growth in weight during the first months, because of greater fat deposition. At 24 months of age, the IUGR-API infants scored below the others on mental items. At 3 years of age the IUGR-API infants had the lowest values on seven of eight developmental measures and on the composite score; at these two time periods, the group with normal birth weight scored the highest, and the IUGR-LPI infants obtained intermediate values. It is concluded that infanst with IUGR tend to follow postnatal growth and developmental patterns that are associated with their physical characteristics at birth.