Background: Animal studies show that prenatal maternal stress may be related to cognitive impairments in offspring. Therefore, we examined whether psychological and endocrinologic measures of stress during human pregnancy predicted developmental outcome of the infant at 3 and 8 months.
Method: Self-report data about daily hassles and pregnancy-specific anxiety and salivary cortisol levels were collected in 170 nulliparous women in early, mid- and late pregnancy in a prospective design, in which healthy infants born at term were followed up after birth.
Results: High levels of pregnancy-specific anxiety in mid-pregnancy predicted lower mental and motor developmental scores at 8 months (p < .05). High amounts of daily hassles in early pregnancy were associated with lower mental developmental scores at 8 months (p < .05). Early morning values of cortisol in late pregnancy were negatively related to both mental and motor development at 3 months (p < .05 and p < .005, respectively) and motor development at 8 months (p < .01). On average a decline of 8 points on the mental and motor development scale was found. All results were adjusted for a large number of covariates.
Conclusion: Stress during pregnancy appears to be one of the determinants of delay in motor and mental development in infants of 8 months of age and may be a risk factor for later developmental problems. Further systematic follow-up of the present sample is needed to determine whether these delays are transient, persistent or even progressive.