Stress: is it a risk factor for small-for-gestational age births?: A secondary data analysis of the NICHD study for successive small-for-gestational age births (the Scandinavian SGA study)
Date
2006
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Publisher
University of Delaware
Abstract
Low birth weight, preterm birth, small-for-gestational age (SGA) and intrauterine growth retardation are the most common causes of neonatal and perinatal mortality and morbidity. Maternal smoking, caffeine, alcohol and drug use are risk factors for low birth weight and preterm birth that have been identified in the past. Of these factors, stress is a multifaceted factor that has been more recently associated with increased risk for preterm birth, low birth weight, intrauterine growth retardation and small-for-gestational age. ☐ The purpose of the current study was to answer the following questions: (1) Is stress a predictor of birth weight and fetal growth? (2) Which of the following stressors – psychosocial, work, life events – are good predictors of birth weight and fetal growth? (3) Does social support reduce the risk of stress-induced small-for-gestational age births? To this end, variables relevant to stress that might have been experienced by the pregnant women were selected for analysis. ☐ The present study is a secondary data analysis of a subset of the National Institute of Child Health and Human Development (NICHD) study of Successive Small-forgestational age Births – The Scandinavian SGA study. Data were analyzed for the 1656 pregnant women who were administered a questionnaire during week 33 of gestation concerning stress-related events and exposure. These women were characterized as having high risk for SGA (n=1096), plus a random sample of women (n=560) not classified as high risk. ☐ Logistic regression analysis failed to show any significant relationship between psychosocial or physical stress experienced by the pregnant woman and the risk for smallfor- gestational age birth. Availability of social support did not have an effect on SGA births. Consistent with previously published findings based on a larger sample by other investigators, however, maternal height, BMI and maternal smoking were significantly associated with small-for-gestational age. Present analysis of our subset showed that for every 10cm increase in the mother’s height there was a decrease in odds for SGA by a factor of 0.592 (OR=0.949, p<0.05). Similarly, for every kilogram/m2 increase in the mother’s BMI, the odds of delivering an SGA infant decreased by a factor of 0.917 (OR=0.917, p<0.05). Maternal smoking was significantly associated with an increase in SGA birth (OR=1.700 with maternal height included in the regression equation; OR=1.654 with maternal BMI in the equation, p<0.05). ☐ Neither overall exposure to work hazards nor exposure to specific work hazards showed a relationship to risk of SGA births.