Mothers’ blood sugar levels and weight gain during pregnancy—as well as their weight before pregnancy—may predict their infants’ unhealthy birth weights, according to research conducted by U-M researchers and Detroit health care providers.
In this two-year study, researchers analyzed medical record data, measured weights, recorded social characteristics and studied the results of the blood-screening test for gestational diabetes conducted during pregnancy for 1,041 Latino mother-infant pairs. The women, most of whom were of Mexican ancestry, received prenatal care at Community Health and Social Services Inc. (CHASS)—a community health center in southwest Detroit—and gave birth at Henry Ford Hospital.
The findings, which appear in the December issue of the American Journal of Public Health, reveal that 42 percent of women entered pregnancy overweight or obese, and at least 36 percent exceeded the weight-gain recommendations of the Institute of Medicine. Twenty-seven percent of the women had at least some degree of glucose abnormality, including 6.8 percent who had gestational diabetes.
“Diabetes tends to cause babies to grow abnormally fat because higher levels of sugar (glucose) and fats (lipids) in the mother’s blood provide extra fuel for fetal growth,” says Edith Kieffer, the study’s lead author and an associate professor in the U-M School of Social Work. “Women with an abnormal screen test have heavier babies on average than women whose screen test is normal, even if they don’t have gestational diabetes.”
Public health officials, researchers and policy-makers long have assumed that babies who are not low birth weight are healthy. Kieffer notes that the health needs of Latino mothers and babies have often been ignored in U.S. health policy and research.
She says this study helps demonstrate that many Latino infants’ birth weights are higher because of less positive factors, namely their mothers’ abnormally high blood sugar levels, and excessive weight and weight gain. Evidence from other studies has shown that these potentially modifiable maternal characteristics are also markers of risk for Type 2 Diabetes in both mothers and their babies. Latinos are developing Type 2 Diabetes at more than twice the rate as non-Hispanic whites and at younger ages, she noted.
Kieffer emphasizes that pregnancy and the first year after birth give health professionals and communities unique opportunities to help prevent Type 2 Diabetes and its many, severe complications. Preconceptional, prenatal and postpartum care and clinic and community-based programs can assist women to eat healthy, get at least moderate amounts of exercise most days of the week.
“These factors are important in achieving and maintaining appropriate weight and glucose status before, during and after pregnancy,” Kieffer says.
The study’s results also suggest that research related to birth weight, including those that assess racial and ethnic disparities in fetal growth, should include measures of glucose tolerance (blood sugar levels and status) during pregnancy, maternal weight and weight gain in addition to more commonly used sociodemographic, prenatal care and behavioral variables.
Kieffer and colleagues plan to help increase women’s awareness of Type 2 Diabetes and its risk factors.
Collaborating with Kieffer were U-M researchers Bahman Tabaei, William Herman Wendy Carman; George Nolan of U-M and previously of Henry Ford Health System; and J. Ricardo Guzman of Community Health and Social Services Inc. in Detroit.
