Ethnic differences in the growth of low‐birthweight infants

Abstract

Differences in growth were investigated among ethnic groups in low-birthweight babies (< 2500 g or < 32 weeks gestation) at birth and at 2-3 years. This prospective study was based on data for all 3091 low-birthweight live births in the South East Thames Region, UK, over a 1-year period, surviving to discharge from hospital. Weights were recorded at birth and at 2-3 years for 998 babies, and head circumferences for 859. These were compared with the UK 1990 reference standards. Ethnic differences were adjusted for parity, multiple birth, smoking and alcohol during pregnancy, mother's height, weight and age, marital status, partner's support and social class. At 2-3 years, there was substantial average catch-up growth only for the weight of infants of > or = 32 weeks' gestation. Babies < 32 weeks gestation had fallen behind. Head circumferences had failed to keep up or had fallen behind for both groups. The ethnic groups had similar birthweight standard deviation scores (SDS). At 2-3 years, Black babies of < 32 weeks' gestation had gained in weight and head circumference compared with White babies (adjusted difference in weight SDS: 0.71, [95% CI 0.28, 1.13]). Asian babies of at least 32 weeks' gestation had smaller heads than White, a difference that increased with time. It was concluded that ethnic differences in the growth of low-birthweight infants are related to gestational age. Although most of the babies born at < 28 weeks' gestation were close to their birthweight reference standards, only the Black infants had maintained their position at 2-3 years. Black infants, particularly when born preterm, tend to put on more weight than White.