Comparison of the risk factors for pre-term delivery and intrauterine growth retardation.

In a follow-up study of the pregnant women interviewed in the Nutrition Canada survey, we investigated predictors of intrauterine growth retardation (less than or equal to 10th percentile of the birthweight-gestational age distribution for the 1972 Canadian population), and pre-term delivery (less than 37 completed weeks of gestation), by classifying these two endpoints as either small-for-gestational age and not pre-term (SGA-NPT), or not small-for-gestational age but pre-term (NSGA-PT). Education, age, household income level, number of previous livebirths, number of cigarettes smoked per day while pregnant, alcohol consumption (spirits only), serum Vitamin C and haemoglobin levels, pre-pregnancy weight, height, and sex of the infant were related to NSGA-PT deliveries in univariate analyses; serum Vitamin A, smoking history, calorie intake, height and pre-pregnancy weight were similarly associated with the risk of SGA-NPT outcomes. When considered jointly in multivariate logistic regression analysis, however, the significant predictors were reduced to: height and pre-pregnancy weight for SGA-NPT and mother's education, sex of the infant, and household income level for NSGA-PT.