Determinants of intrauterine growth retardation: evidence against maternal depletion

This analysis examines the relationship between length of preceding birth interval and risk of intrauterine growth retardation using data on Swedish infants from the 1973 World Health Organization study of perinatal mortality. Results of a multivariate logit analysis demonstrate that the lower than average mean birth weight of infants born after short birth intervals cannot be completely attributed to their shorter mean gestation length. Infants born after birth intervals of 12 months or less are 30% more likely to be small for gestational age (SGA) than infants born 18-59 months after the previous birth, even when the effects of maternal age and parity are controlled. The results obtained here do not support maternal depletion as an explanation for the association between short birth intervals and elevated risk of SGA, since there is no evidence of an attenuation of the risk of SGA with increasing length of interval in the under 18 month birth interval range.