Funded Research

Prenatal and Post-natal Contributors
to Development in Infancy

George M. Tarabulsy, Michel Boivin
École de psychologie, Université Laval, Québec, Québec

Jean-Pascal Lemelin, Département de psychoéducation
Université de Sherbrooke, Sherbrooke, Québec

Summary (PDF 32 KB)

Full Report (PDF 117 KB)

Background

There is increasing evidence that the prenatal environment sets certain aspects of infant cognitive and emotional development during the first months and years of life. This idea has been labelled the "Foetal Programming Hypothesis" (FPH) and researchers who have studied it have shown how specific factors related to maternal stress and the consumption of alcohol, tobacco and drugs during the prenatal period, are related to cognitive, emotional and psychophysiological markers of infant development and functioning.

Maternal stress is also related to increased levels of physiological markers of stress (such as cortisol) which easily crosses the placental barrier, as do alcohol and substances in drug and tobacco products. Such substances have been shown to influence brain development in animal research in regions related to memory and emotional development.

Description

Different prevention strategies have been applied to reduce the levels of these prenatal variables, especially in high-risk populations. The results of these initiatives has been unclear and leave three questions unaddressed:

  • Few prevention strategies have been assessed in designs where mothers have been randomly assigned to different intervention conditions and where the effects of the intervention is shown to be superior to the community and hospital-based services that high-risk expecting mothers receive.
  • Not all studies show expected effects on stress and consumption, and when effects are found, they are rarely correlated to infant developmental outcome.
  • When infant outcome has been assessed, critical postnatal factors known to influence development have often been ignored, such as mother–infant interaction and family conflict.

Findings

Results show that, contrary to expectations, the intervention proved ineffective in changing maternal levels of prenatal stress or consumption. As such, evidence for foetal programming could not be explained using the experimental design that was proposed. Consequently, the programming hypothesis was examined by way of hierarchical regression analyses.

Here, evidence for foetal programming was observed. Specifically, prenatal levels of alcohol consumption were linked to infant salivary cortisol concentrations, and prenatal maternal anxiety was associated to infant cognitive and emotional development.

There was marginal support for a relation between major life events (an indicator of stress) and infant emotional development and maternal smoking and infant cortisol concentrations. Postnatal levels of maternal interactive sensitivity, marital adjustment and daycare experience were unrelated to infant cognitive or emotional outcomes, indicating that at the time infant outcome measures were taken, prenatal factors weighed more heavily in predicting infant outcome.