Monash-led world's study of 1.3 million pregnant women reveals global obesity crisis

Professor Helena Teede

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 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.