Social and anthropometric factors explaining racial/ethnical differences in birth weight in the United States

Area of Science:

• Public Health
• Perinatal Epidemiology
• Human Genetics

Background:

• Significant racial and ethnic disparities in infant birth weight are well-documented in the U.S.
• Limited research has systematically explored the specific factors contributing to these birth weight variations.

Purpose of the Study:

• To investigate the factors contributing to birth weight differences among 14 distinct racial and ethnic groups in the United States.
• To sequentially adjust for maternal, socioeconomic, and behavioral factors to understand their impact on birth weight variability.

Main Methods:

• Analysis of a large dataset of 10,638,415 singleton births in the U.S. from 2009-2012.
• Comparison of average birth weights across 14 racial/ethnic groups, adjusting for multiple variables.
• Sequential adjustment for maternal anthropometrics (height, BMI), gestational weight gain, gestational age, maternal age, parity, and socioeconomic/behavioral factors.

Main Results:

• Birth weights varied significantly across groups, with Japanese infants being 289g lighter and Samoan infants 126g heavier than non-Hispanic white infants.
• Maternal height and BMI explained differences for Asian and Samoan infants; gestational age for Black infants; and gestational weight gain for Japanese infants.
• Maternal age, parity, socioeconomic status, and behavioral factors did not significantly account for birth weight variations among the studied groups.

Conclusions:

• Maternal anthropometrics, gestational weight gain, and preterm birth rates are significant contributors to racial/ethnic birth weight differences.
• Socioeconomic status, maternal age, parity, and behavioral characteristics play a minimal role in explaining these observed disparities.
• Targeted interventions focusing on maternal physical characteristics and pregnancy weight management may help reduce birth weight inequities.