Too Much Pregnancy Weight Gain Too Soon Ups Diabetes Risk

The Scoop

One more reason why packing on too much "baby weight" is a bad idea: excessive pregnancy weight gain, especially when gained quickly during the first trimester, may increase a woman's risk for developing gestational diabetes (GDM), according to new research from California-based Kaiser Permanente Division of Research.

The study, published in the March 2010 issue of the journal Obstetrics and Gynecology, tracked weight gain patterns in 345 pregnant women with GDM and 800 pregnant women with normal blood sugar levels. Women who were slowest to put on weight during their first trimester (just over half a pound per week) were the least likely to develop diabetes, researchers found. Risk for GDM rose by 40 percent when women gained between 0.6 to 0.9 pounds per week during the first trimester; when women gained roughly a pound or more per week during early pregnancy, GDM risk increased by 74 percent.

Women who entered pregnancy already overweight or obese—and who quickly packed on more weight —were most likely to develop diabetes. The takeaway message for all moms-to-be, according to study lead author Dr. Monique Hedderson, Ph.D., is for women and their prenatal care practitioners "...to talk [early on] in pregnancy about appropriate gestational weight gain, especially during the first trimester." Dr. Hedderson also points to the study as good evidence that women may be able to take steps during the first trimester to reduce their risk for gestational diabetes later on in pregnancy. "Weight gain in early pregnancy is a modifiable risk factor for gestational diabetes," Dr. Hedderson notes.

Your Health

Approximately one in every five women will develop high blood sugar levels during pregnancy (gestational diabetes). Though researchers still aren't sure how excessive first trimester weight gain contributes to GDM, it could be that rapid adding pounds triggers "insulin resistance"—a condition in which cells in the body require more and more insulin to properly convert blood glucose into energy. If insulin production can't keep up with demand, too much sugar stays in the blood, causing elevated blood glucose levels. Women with certain risk factors (obesity, family history of diabetes) may be tested for diabetes during the first trimester. All pregnant women are screened for GDM between the 24th and 28th week of pregnancy, when high blood sugar levels are most likely to develop.