The Importance of Healthy Pregnancy Weight

Obesity in pregnant women linked to higher odds of infant death

/ Author:  / Reviewed by: Robert Carlson, M.D Beth Bolt, RPh

(RxWiki News) Obesity can contribute to a range of different health problems, but for pregnant women, those problems may affect two people.

A recent study found that the risk of infant death among obese pregnant women was higher than the risk for children of normal weight women.

The study's findings do not mean that obesity causes the higher risk in children. It could be that other health conditions related to obesity also present risks to the mother's child.

However, the study still reveals the value of maintaining a healthy weight before and during pregnancy.

"Discuss your weight with your OB/GYN."

This study, led by Sean Meehan, MPH, of the University of Nottingham School of Medicine in England, aimed to better understand the link between obesity in pregnant women and their children's risk of death.

The researchers sought all studies related to mothers' obesity and infant mortality in four research databases and located 24 that met their criteria.

How obesity was defined varied across the studies, but in their analysis, the researchers used having a body mass index (BMI) of 30 or greater.

BMI is a ratio of height to weight that is used to measure how healthy someone's weight is.

Infant mortality definitions also varied across the studies included. Some considered an infant death any death of a baby before age 1, while others considered it a death in the first week or first month of life.

Therefore, in this study, a precise definition of "infant death" was not able to be provided.

Pulling the data from these 24 papers, the researchers calculated that the infants of obese women had 1.4 times greater odds of dying than those of normal weight women.

For women who were excessively obese, with a BMI over 35, the odds of infant death were twice as high than for women with normal weight.

However, this analysis did not take into account other health conditions the women might have which could have contributed to their babies' risk of death.

For example, obese women are more likely to have pre-eclampsia, premature birth, high-birth-weight babies and gestational diabetes, all of which may increase the risk of infant death.

Obese women may also have other health conditions, such as undiagnosed heart disease or diabetes or an overall unhealthy diet, which could increase the risk of their child's death.

It is not possible based on this analysis to separate out whether the risk of infant death was directly related to mothers' weight itself or related instead to conditions that obese women often have.

Given how increasingly common obesity is among pregnant women, however, the researchers emphasized the importance of additional research to understand the link between maternal obesity and infant death.

"This study is yet another in a growing body of evidence that reinforces the importance of a healthy diet and a healthy weight," said Andre Hall, MD, an OBGYN at Birth and Women's Care, PA in Fayetteville, NC.

"Obesity in of itself is a risk factor for a host of other medical problems," he said. "Recent evidence is now suggesting that obesity and its associated risk of medical complications may also be an independent risk factor for a developing pregnancy."

"Therefore, increasing emphasis needs to placed on an overall healthy lifestyle to include eating properly, maintaining a healthy weight and exercise," Dr. Hall said.

This study was published April 7 in the journal Pediatrics. The research did not use external funding, and no conflicts of interest were reported.

Review Date: 
April 6, 2014
Last Updated:
April 24, 2014