While the weight a woman gains during pregnancy — and how fast she loses it (or doesn’t) after giving birth — have long been hot topics, people don’t seem to focus on or talk as much about weight before pregnancy. Studies have explored trends in pre-pregnancy BMI, including how increased maternal weight before pregnancy can up the odds of fertility problems, C-section deliveries and infant health issues such as macrosomia — but now, recent research shows that higher pre-pregnancy BMI may shorten a child’s lifespan.
In a study published in BioMed Central, researchers tested 768 Belgian mother-newborn pairs (the moms ranged from age 17 to 44) and found that the higher a woman’s pre-pregnancy BMI, the shorter a newborn’s telomeres tended to be. Telomeres are the protective parts of DNA strands that keep DNA intact (they’re likened to the caps at the end of shoelaces that prevent fraying). Every time a cell divides and copies itself throughout your lifetime, its telomere shortens; ultimately, it becomes too short to work, which prevents cells from replenishing. That’s why longer telomeres are a direct indication of longer lifespans, while the opposite is true of shorter ones.
“Prior to our study, there was no evidence of an association between pre-pregnancy BMI and newborn telomere length,” said study co-author Professor Tim S. Nawrot. “Compared with newborns of mothers with a normal BMI, newborns of women with obesity are older on a molecular level, because shortened telomere lengths mean that their cells have shorter lifespans… So maintaining a healthy BMI during a woman’s reproductive age may promote molecular longevity in the offspring. Our results add to the growing body of evidence that high maternal BMI impacts fetal programming, which could lead to altered fetal development and later life diseases. The public health impact of our findings is considerable as in affluent societies about 30 percent of women of reproductive age are overweight.”
Most of us are well aware of the health risks involved with being overweight, but this study brings a serious wake-up call about how our own weight as mothers could have life-altering consequences for our kids — even if you crash-diet and get healthy before getting pregnant. Of course, you and your doctor should take into account your BMI when you’re trying to get pregnant and how much total weight is healthy to gain (you can find out where you fall here). But regardless, this is one more reason to be vigilant about your health at all times and not just during convenient ones (i.e., bikini season). For more intel on why it’s easier — and smarter — to prevent weight gain than lose it after the fact, check out this study on how much harder it is to lose holiday pounds than fend them off in the first place.