Excessive pregnancy weight gain tied to higher cesarean risk

The U.S. rates of women giving birth by cesarean delivery, or C-section, have risen significantly over the past few decades. C-sections are sometimes medically needed and can save lives. But for lower-risk pregnancies, they pose inherent risks for both mother and baby. Researchers from the Arkansas CEAL Regional Team wanted to see how weight gain during pregnancy impacted cesarean delivery rates across a large national sample and a full range of body mass index (BMI) categories.

The researchers looked at nine years’ worth of data on live births from the National Center for Health Statistics. To isolate the effects of excessive pregnancy weight gain, the births examined were otherwise low in risk. All told, the data covered close to 8 million deliveries. The team referred to the widely accepted, evidence-based recommendations from the Institute of Medicine (IOM) outlining not just how much total weight a woman should gain during pregnancy based on her prepregnancy BMI category, but also at what rate, or how much weight was gained per week.

The researchers’ findings

In their analysis, the researchers found that as prepregnancy BMI increased, so did the risk of having a C-section. Gaining too much weight during pregnancy also increased this risk for all groups, but especially for those with higher prepregnancy BMI. For women whose BMI before pregnancy was in the underweight or normal category, weight gain that was in keeping with the IOM weekly weight gain guidelines lowered the risk of having a C-section. However, risk increased with additional weekly weight gain.

The evidence-informed opportunities

These findings hold meaning for health care providers as well as researchers:

• Providers can advise their patients about the rate at which they gain weight during pregnancy.
• Researchers can study the effectiveness of interventions involving diet and physical activity among groups most heavily impacted by excessive pregnancy weight gain, like low-income or rural women. 

Having a better understanding of the links between C-section delivery and excessive pregnancy weight gain — and what to do about it — may help protect more moms and babies.

Link to article: Excessive gestational weight gain associated with higher risk of cesarean delivery across body mass index categories in the United States