Effects of Gaining Too Much Weight During Pregnancy

Please note that this content is my personal notes from my readings.

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“Nearly two-thirds of American women of childbearing age are overweight; one in five women who gives birth in the United States is obese.  A 2009 study found that up to 73% of U.S. women fail to follow guidelines for recommended weight gain during pregnancy, with most overweight women gaining too much…

Children of Overweight or Obese Mothers Are More Likely To Experience Birth Defects

A number of recent studies have determined, for example, that the offspring of overweight or obese women are more likely to have birth defects (which, despite their name, have their origin at conception or early in gestation).  A 2007 study published in the Archives of Pediatric and Adolescent Medicine found that the incidence of some defects was twice as high among children of obese mothers.  A 2009 study, the largest of its kind in the United States, reported that women who were overweight but not obese had a 15% increased risk of delivering a baby with certain heart defects.

Children of Overweight or Obese Mothers Are More Likely To Become Obese

Perhaps even more troubling is the notion that the prenatal conditions by a woman who is overweight or obese when she becomes pregnant, or who gains an excessive amount of weight during pregnancy, may in turn promote the development of obesity in her child: what scientists call the “intergenerational transmission” of obesity.  A 2007 study of 1,044 mother-child pairs, conducted by researchers at Harvard Medical School, found that greater weight gain by a woman during pregnancy was associated with a heavier child at age three.  Women who gained more than the recommended amount of weight (that is, twenty-five to thirty-five pounds) — and even those whose weight gain was within the recommended range — had four times the risk of having an overweight toddler than women who gained less than the guidelines advise.  A study by the same team, published the following year, suggested that this relationship persists into the offspring’s adolescence: compared to the teenagers of women who had excessive weight gain during pregnancy, those of women who had excessive weight gain weighed more and were more likely to be obese.

Of course, children could well share eating habits, or a genetic predisposition to obesity, with their mothers — so how can we know that the prenatal environment is exerting an influence?  Some researchers have found a clever way around this problem: they have compared children born to obese mothers with their siblings born after the mothers have had successful anti-obesity surgery.  Same mother, different intrauterine environment.  In a 2006 study, published in the journal Pediatrics, researchers found that the children gestated by women post-surgery were 52% less likely to be obese than siblings born to the same mother when she was obese.  Though these children had inherited their formerly obese mothers’ genes, they were no more likely to be obese than the general population.  A second study by the same group, published in 2009, found that children born after their mothers lost weight had lower birth weights and were three times less likely to become severely obese than their older siblings…”

Losing Weight Before Getting Pregnant May Be An Investment In Her Offspring’s Future Health

It may be that the intrauterine environment is as important as genes or family eating habits in passing on a tendency to obesity, says John Kral, a professor of surgery and medicine at SUNY Downstate Medical Center in New York.  If that’s so, he adds, “an obese woman who loses weight before getting pregnant is making an investment in her offspring’s future health.”

– How the Nine Months Before Birth Shape the Rest of Our Lives (2010) by Annie Murphy Paul;

pages 17 – 19