Monash-led World's Study Of 1.3 Million Pregnant Women Reveals Global Obesity Crisis
The world’s largest and most comprehensive international study of more than 1.3 million pregnant women, led by researchers at the Monash University in Melbourne, Australia has found that three out of every four pregnant women worldwide, and their healthcare teams, are failing to achieve a healthy weight gain during pregnancy, leading to preventable adverse health consequences for women and their babies.
The study, published in the Journal of the American Medical Association (JAMA), highlights the disturbing high rate of excess unhealthy weight in mothers at the start of pregnancy and shows that the vast majority of women are not achieving healthy recommended weight gain in pregnancy.
In addition, the researchers found mothers are gaining too much weight during pregnancy, increasing health risks during pregnancy and beyond, and increasing risks for their children to be overweight or obese.
The research team, led by Professor Helena Teede and Dr Rebecca Goldstein from the Monash University Faculty of Medicine, Nursing and Health Sciences, reviewed more than 5300 studies and in a large scale international collaboration, reanalysed and integrated pregnancy data from 23 groups across Europe, Asia and the United States.
The study sought to affirm the relevance of older US guidelines for healthy weight gain in pregnancy. These 1990 Institute of Medicine Guidelines were originally based on 1980 data of a largely Caucasian population. Updated in 2009, these guidelines, “were still based on women with a lower general weight than our current population of mothers with limited ethnic diversity,” Dr Goldstein says. While these guidelines are endorsed by the American College of Obstetricians and Gynaecololgists “they are not universally implemented,” with considerable lost prevention opportunities, the JAMA paper authors add.
The Monash-led international study – which included a broad range of ethnically diverse pregnant women, explored their weight gain during pregnancy, their health and the health of their babies – had key findings according to Professor Teede that include that, at the time of pregnancy:
- 7% women were underweight
- 55% normal weight
- 38% were overweight and obese
During pregnancy striking 3 in 4 women did not gain healthy recommended weight with increased risks for mothers and babies with:
- 23% gaining less than healthy weight gain
- Strikingly almost half gaining more than healthy weight gain, with higher rates in western countries
Women who gained more than recommended were at higher risk of having large babies and requiring a caesarian birth.
Women who gained less than the recommended weight during pregnancy were at increased risk of having smaller babies and preterm birth.
Importantly the study found that entering pregnancy underweight and failing to put on recommended weight during pregnancy led to:
- 8% risk of having an underweight baby
- 8% increase in preterm birth
Professor Teede said that current study “represents the largest contemporary international snapshot of women’s weight coming into pregnancy and their weight gain during pregnancy, how this is impacting of their and their baby’s health and the healthcare system.”
Importantly the study takes into account “our more contemporary population of mothers who are increasingly entering pregnancy at an unhealthy weight and it covers the diversity of race across Europe, US and Asia,” Professor Teede said.
Professor Teede said that the new evidence published in JAMA emphasises the need for urgent strategies to monitor, support women and optimise healthy weight in mothers both before and during pregnancy, endorsing guidelines recommending that women gain between 12.5-18kg for underweight women, 11.5-16kg for healthy weight women, 7-11kg for overweight women and 5-9kg for obese women during pregnancy.
In 2015 Professor Teede led a team which produced the National Health and Medical Research Council (NHMRC) Case for Evidence-Based Action in obesity prevention, calling for vital lifestyle intervention in preconception and pregnancy. “The case for action aligns with WHO recommendations to prioritise prevention of excess weight gain in reproductive aged women before and during pregnancy,” she said. “This latest study means - more than ever - that weight needs to be monitored in pregnancy and women provided with support to improve lifestyle. Health professionals need to be encouraged and trained in having "healthy conversations" introducing relatively simple effective lifestyle interventions to support women before, during and after pregnancy. For health services and policy makers recognition that effective simple health lifestyle interventions are available and now need to be incorporated into routine care to optimise reach and availability for all women". We know what to do and now need to implement the available evidence into action.
MCHRI and Monash University are working towards these goals.
For further information about this research, please email Dr Rebecca Goldstein.