Weight Gain After Pregnancy and Stillbirth Risk

Weight Gain After Pregnancy and Stillbirth Risk Researchers focused on women who previously had a healthy BMI
WebMD News from HealthDay

By Robert Preidt

HealthDay Reporter

THURSDAY, Dec. 3, 2015 (HealthDay News) -- Weight gain after a first pregnancy might raise the risk of infant death and stillbirth in a second pregnancy, a new study suggests.

In mothers who were previously a healthy weight, even moderate weight gain between the two pregnancies was associated with increasing the odds for infant death, researchers reported Dec. 3 in The Lancet.

"The public health implications are profound," study author Sven Cnattingius, a professor at the Karolinska Institute in Sweden, said in a journal news release.

"Around a fifth of women in our study gained enough weight between pregnancies to increase their risk of stillbirth by 30 to 50 percent, and their likelihood of giving birth to babies who die in infancy increased by 27 to 60 percent, if they had a healthy weight during their first pregnancy," Cnattingius said.

But while the study detected an association between mother's weight gain and infant death and stillbirth, it didn't actually establish a direct cause-and-effect relationship.

The research team analyzed data from more than 450,000 Swedish women who gave birth to their first and second child between 1992 and 2012.

Overall, they found that women whose body mass index (BMI) rose more than four units (about 24 pounds for an average-height woman) between pregnancies had a 50 percent greater risk of their second baby dying within the first four weeks of life compared to women whose weight remained stable between pregnancies. BMI is a measurement of body fat based on height and weight.

Among mothers at a healthy weight during their first pregnancy, a BMI increase of two to four points (13 to 24 pounds in someone of average height) by their second pregnancy was linked to a 27 percent higher risk of infant death. Among those whose BMI rose four points or more, the risk was 60 percent higher, the study found.

The study authors suggested that BMI gains in healthy-weight women may reflect a greater increase of fat mass than in obese women, and therefore present a greater risk.

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