Pregnant Belly

Researchers have found that an unhealthy weight during a woman's first pregnancy can negatively affect her next pregnancy, even if she didn't experience any complications the first time around.

A study recently published in the American Journal of Obstetrics and Gynecology discovered that "while moms who weigh too much or too little might have uncomplicated pregnancies and deliver healthy babies the first time around, our research shows they are still at increased risk of adverse outcomes during their second pregnancies," according to senior author Jen Jen Chang, Ph.D.

Researchers from Saint Louis University followed more than 100,000 women from 1989 to 2005. Women who were underweight during their first pregnancy had a 40 percent greater risk for having a small baby the second time around, and were 20 percent more likely to give birth to their second baby early.

Complications during second pregnancies were even more apparent for women who were obese when they first became pregnant. These women were 54 percent more likely to have a large baby, 156 percent more likely to have preeclampsia, and 85 percent more likely to give birth via C-section.

The most surprising part: These risks still existed even if the woman was at a normal, healthy weight when she got pregnant again.

"The bottom line for physicians and second-time moms is not to let down their guard even if things went well for moms with unhealthy weight during the first pregnancy or if those moms reach a normal weight when they become pregnant again," noted Chang.

Caitlin St John is an Editorial Assistant for who splits her time between New York City and her hometown on Long Island. Follow her on Twitter: @CAITYstjohn

Image: Pregnant Belly via Shutterstock