Possible Deadly Consequence of Obesity before Pregnancy

Overweight and obesity in mothers linked to increased fetal and infant deaths

/ Author:  / Reviewed by: Joseph V. Madia, MD Beth Bolt, RPh

(RxWiki News) Being overweight has a wide range of health implications. One new study looked at how a pregnant women's weight may affect the child they carry.

The researchers found a significant link between a mother’s pre-pregnancy body mass index (BMI), a measure of a person’s body fat, and increased risk of fetal and infant death.

This study was unable to determine if the increased risk of fetal and infant death was caused directly by the mother’s weight or if other health problems associated with higher BMI, such as high blood pressure and type 2 diabetes, played a role.

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This study was led by Dagfinn Aune, MS, from the Department of Epidemiology and Biostatistics at Imperial College London.

The research team looked at 38 studies that included more than 40,000 fetal and infant deaths dating from as far back as 1947 to as recently as January 2014. The accepted studies came from around the world.

The researchers looked at the link between a mother’s pre-pregnancy body mass index (BMI) and the risk of fetal death, stillbirth, miscarriage and infant death.

BMI measures a person’s weight adjusted for their height. A BMI between 19 and 24 is considered normal and healthy, while a BMI between 25 and 29 is overweight, and anything over 30 is considered obese.

The data showed a significant correlation between the mothers' BMI and the risk of death for the fetus and infants under 1 year of age.

Aune and colleagues noted that the risk of death to the fetus or infant of a mother with a BMI greater than 40 was two to three times greater than those of a mother with a BMI of 20.

Dr. Aune and team found a statistically significant increase in fetal and infant death for every five-point increase in the mothers' pre-pregnancy BMI.

The research team said that conditions associated with overweight and obesity may be to blame for the increased risk of fetal and infant death. These conditions can include type 2 diabetes and pre-eclampsia, a form of high blood pressure, in the mother as well as a higher rate of fetal and infant birth defects.

The authors concluded that their findings indicated a need for weight management guidelines for women planning to become pregnant in order to reduce the risk of fetal death, stillbirth and infant death.

These authors acknowledged that further study is needed in low and middle-income countries, with more consistent definitions, which was a limitation of their own study.

This study was published April 15 in JAMA.

This project was supported by a grant from the Norwegian SIDS and Stillbirth Society.

The authors made no disclosures.

Review Date: 
April 15, 2014
Last Updated:
April 18, 2014