Well, here's a new potential reason to be worried about having a cesarean section. A recent study from Harvard found that having a C-section affects a child's weight through at least young adulthood, with babies delivered through that method 15 percent more likely than babies born vaginally to be obese later in life. And the likelihood for obesity gets worse when the C-sections are not medically necessary, going all the way up to 30 percent.

The study, which was published in JAMA Pediatrics, was conducted from 1996 to 2012. Many other studies purporting to show a link between obesity and the procedure have a much shorter frame of reference, making this one a big deal. The study also looked at siblings within the same family, where children have the same genes and would likely be getting the same diet. Shockingly, the researchers found the following:

In within-family analysis, individuals born by cesarean delivery had 64 percent (8 percent to 148 percent) higher odds of obesity than did their siblings born via vaginal delivery.

The risk of obesity did seem to decrease over time. Children ages 9-12 born via C-section were 23 percent more likely to be obese than those with vaginal births, but the percentile dropped to 16 percent for teenagers, and 10 percent for young adults up to age 28.

So what accounts for the difference in weight? Researchers believe that children born via C-section don't get exposure to all the special bacteria in the birth canal that ends up hanging out in a baby's gut and affecting his or her metabolism. But The Guardian pointed out that it could also be due to breastfeeding. C-section babies are less likely to be breastfed than babies born vaginally, and breastfeeding helps with all that good gut bacteria as well.

This is all very important information for expectant mothers to know, as the rate of C-section deliveries in the United States shoots ever higher, even though it seems that a lot of them aren't medically necessary. Yes, C-section deliveries have saved many, many lives. But oftentimes doctors will reportedly perform the procedure because they may want to move on to other patients, or because they're afraid of getting sued for malpractice. Now, though, people are starting to realize that a C-section should not necessarily be viewed as a cure-all, but as a medically necessary procedure that comes with its own risks.

Of course, this new study doesn't magically reveal all the information you'd ever want to know about the effects of C-section births. But it's a really good start, and an excellent set of findings for expectant mothers to consider when going through a low-risk birth.