When Bigger Women Are Expecting

Overweight and obese pregnant women at higher risk for complications

/ Author:  / Reviewed by: Robert Carlson, M.D

(RxWiki News) Part of being pregnant is gaining weight. Women who already carry extra pounds before getting pregnant, though, might face more risks than women who don't.

A recent study found that pregnant women with higher BMI levels were linked to increased risks for different complications.

Overweight and obese women were more likely to experience high blood pressure or gestational diabetes during pregnancy, for example.

These findings suggest that the healthier a woman's weight is before she gets pregnant, the more likely she is to reduce her risk for some of these complications.

"Discuss your weight with your OB/GYN."

This study, conducted by Valerie Holmes, Centre for Public Health, Queen’s University Belfast in United Kingdom, looked at the influence of pregnant women's weight on their and their baby's outcomes during pregnancy and birth.

The researchers studied 30,298 pregnancies involving a single baby (no multiples) that occurred between 2004 and 2011 in Northern Ireland.

The researchers categorized the women's weight based on their body mass index (BMI), a ratio of their height to weight.

Women with a BMI of less than 18.5 were considered underweight, and women with a BMI of 18.5 to 24.99 were considered a normal (healthy) weight.

Women with a BMI of 25 to 29.99 were considered overweight, and women with a BMI of 30 or higher were considered obese.

The researchers found that women who were overweight or obese were about twice as likely as women with a normal weight to develop high blood pressure disorders during pregnancy.

Overweight women were also about 1.7 times more likely than women with a normal weight to develop gestational diabetes. Obese women were nearly four times more likely to develop gestational diabetes.

Gestational diabetes is a condition in which a woman who did not previously have diabetes develops it during pregnancy.

Overweight and obese women were slightly more likely than women with normal weight (about 20 to 30 percent more likely) to need to have their labor induced.

They were about 40 percent more likely if overweight and 80 percent more likely if obese to need a cesarean section or to experience postpartum hemorrhage (severe bleeding).

Overweight women were about 1.5 times more likely, and obese women were almost twice as likely, to have an oversized baby, compared to women with a normal weight.

Women who were extremely obese (BMI of 35 or greater) had higher risks for all of these outcomes.

Women with the highest level of obesity, with a BMI of 40 or greater, were at higher risk for more serious outcomes.

Compared to women with a normal weight, these extremely obese women were 1.6 times more likely to have a preterm birth and three times more likely to have a stillbirth.

Extremely obese women were twice as likely to require more than five days in the hospital after having their baby and 1.6 times more likely for their baby to require care in the neonatal intensive care unit (NICU).

This study was published in the July issue of BJOG: An International Journal of Obstetrics and Gynaecology.

The research did not use external funding, and the authors declared no conflicts of interest.

Reviewed by: 
Review Date: 
July 11, 2013
Last Updated:
July 29, 2013