Low birth weight raises death risk into adolescence

"We know low birth weight is associated with increased mortality rates in infancy; however, its association with mortality in later childhood and adolescence is less clear cut," says Sailesh Kotecha. (Credit: iStockphoto)

Babies born with a low birth weight are at an increased risk of death during infancy and through to adolescence compared to babies born at a normal weight, a new study of more than 12 million births in England and Wales shows.

Published in the journal PLOS Medicine, the findings show that of the 12,355,251 live births between 1993 and 2011, there were 74,890 (.61 percent) deaths between birth and 18 years of age, with 57,623 (77 percent) occurring in the first year of life and 17,267 (23 percent) occurring between 1 and 18 years of age.

Death rates were higher in babies with low birth weight at both age groups, with death occurring 130 times more frequently in those born at a very low birth weight (approximately 5.5 pounds) than normal birth weight in infancy.

Conditions of the nervous system, accounting for 20 percent, and respiratory system, accounting for 16 percent, were leading causes of death in the lowest birth weight group while cancers and external conditions (including accidents) were the primary causes of death in low birth weight groups.

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“We know low birth weight is associated with increased mortality rates in infancy; however, its association with mortality in later childhood and adolescence is less clear cut,” says Sailesh Kotecha, a professor at Cardiff University.

“This study is significant as it shows, for the first time, that low birth weight is associated with increased death rates from infancy right through to adolescence.”

While the study was observational, researchers believe it reinforces the need to target factors known to contribute to low birth weights to help cut deaths.

“The study reaffirms the need to tackle important factors such as maternal smoking and deprivation which are well known to contribute to low birth weight, Kotecha says. “By better understanding and ameliorating influences that lead to low birth weight, deaths in infancy and beyond could be cut.”

Source: Cardiff University