Mom's Extra Pregnancy Pounds May Raise Child's Heart Risks
But optimal weight gain for best outcomes still unclear, study says
TUESDAY, June 1, 2010 (HealthDay News) -- Children of women who gain too much weight during pregnancy tend to be more overweight and develop more risk factors for heart disease, new research indicates.
The results of the study, which the researchers claim is the most detailed one of its kind, are based on data from women of various pre-pregnancy weights and their children up to the age of 9 years.
"I suspect that a lot of women feel that pregnancy is a time that they should eat much more and can eat more," lead author Debbie Lawlor, a professor of epidemiology at the University of Bristol in the United Kingdom, said in a news release. "More studies are needed that look at the whole picture to see if there is an optimal weight that will not increase the risk of low birth weight babies and not increase the risk of negative outcomes in the mother and baby at the time of birth and later in their lives."
The report, published in the June 1 issue of Circulation, concerns women who gain in excess of the Institute of Medicine's (IOM) guidelines for pregnancy weight. For women of normal weight, that means ideal gains of between 25 and 35 pounds, whereas for overweight women the ideal gain range is from 15 to 25 pounds.
Underweight women are recommended to gain 28 to 40 pounds and for obese women the recommendation is 11 to 20 pounds. The pre-pregnancy weight categories are based on the body mass index (BMI) scale, which takes into consideration both height and weight.
For the current analysis, the British research team began tracking about 6,700 women, nearly all of whom were white, and their offspring for a nine-year period, starting in 1991.
In addition to maternal weight gain during pregnancy, child body measurements and blood pressure readings were repeatedly collected over the study period.
Lawlor and her colleagues found that relative to children of mothers who stuck close to IOM guidelines, mothers who gained too much had children with greater BMIs of just over 2 pounds, nearly an inch larger waist size, more than 2 pounds of additional body fat, higher blood pressure, higher markers of inflammation in the blood, and lower levels of "good" cholesterol.
Such increases were most evident among children whose mothers had gained over one pound per week following the first trimester, the researchers noted.
"Our results show that in trying to work out what the ideal weight gain in pregnancy should be, we need to consider later outcomes in the offspring as well as outcomes around the time of birth," said Lawlor. "But, I believe we are still a long way from being absolutely clear what the optimal weight gain in pregnancy is for the best outcomes in the short- and long term for both mother and child."
For more on pregnancy weight gain, visit the American Pregnancy Association.