Beyond biology: the social context of prenatal behaviour and birth outcomes.

Objectives: In this study we examine the factors that are associated with adverse birth outcomes using a representative national sample. In our analysis we take into account factors which are related to the mother's behaviour during pregnancy and also consider the socio-economic circumstances of the family.
Methods: A series of logistic regression models are used to determine the increased risks of low birth weight, preterm, and small for gestational age births associated with maternal smoking, alcohol consumption and high blood pressure in relation to socio-economic factors, such as family dysfunction, social support, income adequacy, age, and education.
Results: All socio-economic factors showed gradients of maternal smoking during pregnancy while only mother's education and socio-economic status demonstrated gradients of alcohol use and high blood pressure. Maternal smoking, high blood pressure, higher levels of family dysfunction, and lower levels of mother's education were found to significantly increase the risk of an adverse birth outcome.
Conclusions: Interventions designed to mitigate the hazards of adverse birth outcomes should be designed to reflect the gradients of risky prenatal maternal behaviours associated with age, education, income, and family dysfunction.