Very obese women should lose weight during pregnancy for a healthy baby

May 14, 2018, Elsevier
Graph showing the balanced risk of having an SGA or LGA baby - Maternal Fetal Corpulence Symbiosis (MFCS). Credit: Elsevier, Heliyon

Very obese women should actually lose weight during pregnancy in order to have a healthy baby, contrary to current recommendations, according to a new study in the journal Heliyon. The researchers behind the study, from Centre Hospitalier Universitaire Sud Réunion in France, say the current guidelines for weight gain in pregnancy should be adjusted for better outcomes in underweight and very obese women and their babies.

The new study reveals the optimal gain for that would give them a balanced risk of having a very small or very large baby. The findings will enable to give their patients more personalized recommendations. The team has developed an online calculator that can advise women on their ideal weight gain for the safest birth outcome, based on the research.

"The results of our research provide a solution to the conundrum affecting the 135 million pregnancies per year on this planet," said lead author Dr. Pierre-Yves Robillard. "Women want to know what their optimal weight gain should be to have their baby as safely as possible, and their maternity care providers want to know what advice they can give women throughout their . While our results show the recommendations are fine for women in the normal weight range, we have shown they are not ideal for very underweight and very overweight women."

There is a strong link between the weight of mother and baby: very underweight mothers tend to have smaller – called small for gestational age (SGA) babies – and morbidly obese mothers tend to have more large for gestational age (LGA) babies. These babies are at higher risk of conditions like heart attacks, hypertension, obesity and diabetes as adults than babies born at normal weight.

In order to ensure babies have the safest births and healthiest lives possible, there are guidelines recommending the ideal weight gain during pregnancy based on body mass index (BMI). These guidelines, set by the US Institute of Medicine in 2009, have been subject to some controversy: in countries where women are generally smaller, such as Japan and Korea, healthcare providers have suggested the weight gain at the lower end of the spectrum is not sufficient. With the increasing burden of obesity in many countries, it has been suggested that very should in fact lose weight during pregnancy.

Graph showing MFCS values for each BMI category. Credit: Elsevier

To test these claims, Dr. Robillard and the team carried out a 16.5-year observational study. They recorded the pre-pregnancy BMI, weight gain, and weight of the baby of 52,092 women who gave birth at full term. The first finding was that only women with a normal BMI had a balanced risk of having an SGA or LGA baby (both 10 percent risk); they call this crossing point the Maternal Fetal Corpulence Symbiosis (MFCS).

They then looked at how this MFCS shifted with BMI and weight gained during pregnancy. They pinpointed for each BMI category what the optimal weight gain should be for a balanced risk of having an SGA and LGA baby. This revealed that although the current recommendations are correct for women with a normal BMI, they are not correct for underweight or obese women.

According to the study, a woman with a BMI of 17 should gain about 22kg instead of the recommended 12.5-18kg. An obese woman with a BMI of 32 should gain 3.6 kg instead of the recommended 5-9kg. And a very obese women with a BMI of 40 should actually lose 6kg.

"We were surprised to find such a linear connection between BMI, weight gain and MFCS," said Dr. Robillard. "The results will greatly facilitate an individualized approach when advising women about their optimal weight gain during pregnancy without having to put them into fixed categories – using the equation we uncovered, it's possible to give specific advice based on the exact BMI of the woman."

The results have already led to an online calculator in which a woman can enter their height and weight to get a specific recommendation for her optimal , based on the research results. This could be developed into an app for women and their healthcare providers.

Explore further: Weight gain greater, less than recommended during pregnancy linked with increased risk of adverse outcomes

More information: Pierre-Yves Robillard et al, Relationship between pre-pregnancy maternal BMI and optimal weight gain in singleton pregnancies, Heliyon (2018). DOI: 10.1016/j.heliyon.2018.e00615

Related Stories

Weight gain greater, less than recommended during pregnancy linked with increased risk of adverse outcomes

June 6, 2017
In an analysis that included more than 1.3 million pregnancies, weight gain during pregnancy that was greater or less than guideline recommendations was associated with a higher risk of adverse outcomes for mothers and infants, ...

Only 25 percent of women receive appropriate advice on pregnancy weight gain

February 27, 2018
A new study of the role of healthcare provider recommendations on weight gain during pregnancy showed that while provider advice did influence gestational weight gain, only about one in four women received appropriate advice ...

Weight gain between pregnancies linked to increased risk of gestational diabetes

August 1, 2017
The risk of developing gestational diabetes mellitus (GDM) increases with increased weight gain between pregnancies, according to a new study published in PLOS Medicine by Linn Sorbye of the University of Bergen, Norway, ...

Many pregnant NZ women are in the dark about healthy weight gain in pregnancy

August 5, 2016
A large proportion of pregnant New Zealand women are at higher risk of poor health outcomes because they don't know how much weight they should be putting on during pregnancy, new University of Otago research suggests.

Unhealthy pregnancy weight gain tips the scales for mothers seven years later

October 22, 2015
Unhealthy weight gain in pregnancy has been linked with postpartum weight retention but until now its long-term effects had been understudied in low-income and minority populations who are at high risk for obesity. For the ...

Even 'healthy' weight gain raises pregnancy diabetes risk

April 4, 2017
University of Queensland School of Public Health researcher Akilew Adane said women who gained more than 2.5 per cent of their body weight each year had almost triple the risk of gestational diabetes compared to women who ...

Recommended for you

Early postpartum opioids linked with persistent usage

December 14, 2018
Vanderbilt researchers have published findings indicating that regardless of whether a woman delivers a child by cesarean section or by vaginal birth, if they fill prescriptions for opioid pain medications early in the postpartum ...

Large restaurant portions a global problem, study finds

December 12, 2018
A new multi-country study finds that large, high-calorie portion sizes in fast food and full service restaurants is not a problem unique to the United States. An international team of researchers found that 94 percent of ...

A correlation between obesity and income has only developed in the past 30 years

December 11, 2018
It is well known that poorer Americans are more likely to be obese or suffer from diabetes; there is a strong negative correlation between household income and both obesity and diabetes. This negative correlation, however, ...

BMI is a good measure of health after all, new study finds

December 11, 2018
A new study from the University of Bristol supports body mass index (BMI) as a useful tool for assessing obesity and health.

Simple tips to curb overindulgence can help stop pounds piling on at Christmas

December 10, 2018
A study by the University of Birmingham and Loughborough University has shown that regular weighing at home and simple tips to curb excess eating and drinking can prevent people from piling on the pounds at Christmas.

Hysterectomy linked to memory deficit in an animal model

December 6, 2018
By age 60, one in three American women have had a hysterectomy. Though hysterectomy is a prevalent and routine surgery, the removal of the uterus before natural menopause might actually be problematic for cognitive processes ...

0 comments

Please sign in to add a comment. Registration is free, and takes less than a minute. Read more

Click here to reset your password.
Sign in to get notified via email when new comments are made.