Fetal growth, early postnatal growth and motor development in Pakistani infants

Background Studies have often compared the postnatal motor development of ' small' versus 'normal' newborns. Not much is known about the associations b etween a broad spectrum of size at birth and motor development. The effect of early postnatal growth on motor development is Little researched. Growth failure in terms of shortness and thinness should be differentiated, but n ot many studies have the data for this analysis. Methods This is a longitudinal study of infants born in Lahore, Pakistan, b etween 1984 and 1987. Age at commencement of independent walking and age at 'building a 3-cube tower' were taken as indicators of gross and fine motor development, respectively. Size at birth was captured by length and thinne ss as continuous variables: postnatal growth from birth to 6 months of age was measured by changes in length and thinness. Adjustment for covariates a nd handling of censored cases were performed by generalized log gamma regre ssion. Results Thinness at birth and postnatal stunting and wasting had a linear, inverse association with gross motor development (each P < 0.05). Birth len gth had a non-linear, inverse association with this outcome (P < 0.05). Bir th length, thinness at birth and postnatal wasting had a linear, inverse as sociation with fine motor development (each P < 0.05). Conclusions Both fetal and early postnatal growth over a broad spectrum may affect infants' motor development. It is not just the babies who were very small at birth that suffered. Birth length appeared to be more influential than other anthropometric indicators.