Poor Predictors of Fetal Alcohol Syndrome Fetal Alcohol Syndrome

Birthweight and Size are Poor Predictors of Fetal Alcohol Syndrome

Birthweight and Size are Poor Predictors of Fetal Alcohol Syndrome

Sampson and colleagues (1994) sought to better understand the relationship between prenatal alcohol exposure, birth size, and the neurobehavioral consequences that predictably emerge during childhood and adolescence. The main thesis of the paper is that prenatal alcohol exposure will impact birth size, but it is unknown how long after birth the correlation remains statistically significant. Since it has already been conclusively established that prenatal alcohol exposure of sufficient magnitude will result in measurable neurobehavioral deficits later in life, the authors simply examine the correlation between the amount of alcohol consumed during gestation and body measures up to the age of 14.

Rationale

At the time that this article was published, the research concerning a causal relationship between prenatal alcohol exposure and birth size had produced conflicting results (reviewed by Sampson, Bookstein, Barr, and Streissguth, 1994). Since it is important to understand whether birth weight, length, and head circumference is impacted by prenatal alcohol exposure and to what degree, Sampson and colleagues attempted to resolve this question by examining a large cohort longitudinally for 14 years. The reasoning behind the long study period is based on the findings of a few studies that differences in birth size remain correlated with maternal...

The issue of correlation with neurobehavioral changes was not addressed, because this had already been conclusively established by the time this study was conducted.
Methods

A large Seattle, Washington cohort (N = 1,529) of mostly White, married, middle-class women were interviewed about their smoking, alcohol, and drug habits. Out of the 1,437 births, 553 infants were chosen for the longitudinal study. The main independent variable was maternal alcohol use during pregnancy, based on ounces per day, consumption frequency, binge drinking, maximum number of drinks per occasion, and average number of drinks per occasion. The dependent variables were child weight, body length, and head circumference at six different ages, from birth to 14 years of age. An effort was made to include women who were heavy, moderate, light, or non-drinkers during pregnancy, thereby providing a gradient in terms of alcohol use.

Results

Of the 553 births, only 12 or 2.1% met the criteria for low-birthweight (Sampson, Bookstein, Barr, and Streissguth, 1994). This was well below the U.S. national average of 5.1% at the time of the study. However, the number and magnitude of negative correlations revealed drinking severity predicted reduced birth size. The strength of this correlation diminished gradually between birth and 18 months, suggesting that the impact of drinking during pregnancy on child size is lost well before age the age of 2. The most consistent and strongest predictor of reduced neonatal size is average ounces…