Prenatal weight gain, term birth weight, and fetal growth retardation among high-risk multiparous black and white women

Abstract

Objective: To examine the association of prenatal weight gain below, within, and above the Institute of Medicine guidelines with birth weight and fetal growth restriction (FGR) among low-income, high-risk black and white women.

Methods: Eight hundred three black and 365 white women were grouped by pregravid body mass index (BMI): low (below 19.8), normal (19.8-26), high (above 26-29), and very high (above 29). The impact of maternal weight gain on birth weight and race-specific FGR was determined while controlling for sociodemographic and reproductive variables and for time between last weight observation and delivery.

Results: One-third of both black and white women failed to achieve the Institute of Medicine minimum recommended gain for pregravid BMI. More women with low BMI gained less than the recommended weight as compared with those having normal, high, or very high BMI. Nonobese black women (BMI 29 or below) delivered fewer infants with FGR as weight gain increased from below the recommended range (17.9% FGR) to within (10.3% FGR) or above (3.8% FGR) the range; corresponding data for nonobese white women were 20.9, 19.1, and 10.5% FGR, respectively. Obese black women (BMI above 29) also delivered fewer infants with FGR (4.2%) when they exceeded the minimum gain (6 kg) than did white women (11.8%). When analysis of covariance was used to adjust mean birth weight, black women in each pregravid BMI category delivered increasingly larger infants (P < or = .01 for each category) as they met or exceeded the guidelines; among white women this trend was attenuated.

Conclusion: These observations support the Institute of Medicine suggestion that black women strive for prenatal weight gain at the upper end of the recommended range for pregravid BMI.