1. Objectifs

Intentions :
« Our objective was to determine the extent to which the severity and timing of exposure to the ice storm during the pregnancy explains variance in general intellectual and language development of 2-y-olds, above and beyond perinatal factors, such as, gestational age, birth weight, birth complications, and maternal postpartum depression, and socioeconomic status, which have been associated with developmental outcomes. » (p. 401)

Questions/Hypothèses :
« We hypothesized that toddlers who were born to mothers who experienced higher levels of PNMS would exhibit poorer general intellectual and language functioning. We expected that the effect of PNMS would be greatest in toddlers whose mothers were exposed to the ice storm early in their pregnancies. » (p. 401)

2. Méthode

Échantillon/Matériau :
« The toddlers in the present study represent a subsample (n = 58) of a prospective longitudinal study examining the potential effects of PNMS on pre- and perinatal birth outcomes and subsequent development of children exposed in utero [...]. » (p. 402)

Instruments :
- Questionnaire sur les catégories d’exposition à des catastrophes;
- Impact of Event Scale-Revised (IES-R);
- Outcomes of the Pregnancy Questionnaire;
- Mental Scale of the Bayley Scales of Infant Development (2nd ed.);
- MacArthur Commmunicative Development Inventory (MCDI), adaptation française.

Type de traitement des données :
Analyse statistique

3. Résumé

« Prenatal maternal stress has been shown to impair functioning in nonhuman primate offspring. Little is known about the effects of prenatal stress on intellectual and language development in humans because it is difficult to identify sufficiently large samples of pregnant women who have been exposed to an independent stressor. We took advantage of a natural disaster (January 1998 ice storm in Quebec, Canada) to determine the effect of the objective severity of pregnant women’s stress exposure on general intellectual and language development of their children. [...]
The [...] analyses indicated that the toddlers’ birth weight and age at testing accounted for 12.0% and 14.8% of the variance in the Bayley MDI scores and in productive language abilities, respectively. More importantly, the level of prenatal stress exposure accounted for an additional 11.4% and 12.1% of the variance in the toddlers’ Bayley MDI and productive language abilities and uniquely accounted for 17.3% of the variance of their receptive language abilities. The more severe the level of prenatal stress exposure, the poorer the toddlers’ abilities. The level of prenatal stress exposure accounted for a significant proportion of the variance in the three dependent variables above and beyond that already accounted for by non-ice storm-related factors. We suspect that high levels of prenatal stress exposure, particularly early in the pregnancy, may negatively affect the brain development of the foetus, reflected in the lower general intellectual and language abilities in the toddlers. » (p. 400)