Babies born to obese mothers are 35 percent more likely to die before the age of 55, according to a large Scottish study.
They are also 29 percent more likely to go to hospital as a result of stroke, angina or heart attack.
Doctors believe that excess body fat in pregnant women can cause permanent changes to their unborn child's metabolism, which can lead to health issues throughout life and possibly premature death.
Researchers from the universities of Aberdeen and Edinburgh studied more than 38,000 babies born between 1950 and 1976.
The mothers' weights were recorded during pregnancy. The researchers then looked at death records for the children, and found they were 35 percent more likely to die young if their mother's body mass index (BMI) was 30 or higher when they were pregnant.
BMI calculates healthy weight levels by dividing the square of your height by your weight. A BMI between 18.5 and 25 is considered healthy. Anything over 30 is considered obese.
Twenty-one percent of the women in the study were overweight and four percent were obese.
Heart disease was the leading cause of death, accounting for 24 percent of the men's deaths and 13 percent of the women's. Cancer was responsible for 25 percent of men's deaths and 40 percent of women's.
Dr Robert Grenfell, the Heart Foundation's national director of cardiovascular health, said the results were concerning, given the number of overweight and obese women of childbearing age.
In Australia, 35 percent of women aged 18 to 24 are overweight or obese.
"The Heart Foundation is concerned that today's children may be the first generation in history to die at a younger age than their parents," he said.
Dr Grenfell said women needed clearer health messages to make maintaining a healthy weight simpler.
"Mums are constantly being bombarded with information on how to be healthy, but so much of it gets dumped in the 'too hard' basket because it is complicated, confusing or contradictory," he said.
We know that women tend to worry more about their children, partner and parents than themselves, but actually one of the best ways for mums to improve their family's health is to put themselves first and focus on their own health."
The study was published in the British Medical Journal.
Source: Daily Mail Author: Kimberly Gillan; Approving editor: Rory Kinsella