News Author: Laurie Barclay, MD

April 27, 2006 — Breast-feeding for more than 3 months may reduce the risk for childhood obesity in offspring of women with gestational diabetes mellitus (GDM), according to the results of a brief report in the May issue of Diabetes Care.

"Previous studies reported a high risk of obesity in children of mothers who have diabetes during pregnancy," write Ute M. Schaefer-Graf, MD, from the Vivantes Medical Center in Berlin, Germany, and colleagues. "Reports pertaining to the effects of breast-feeding following a pregnancy complicated by diabetes have focused on the delay or prevention of the appearance of islet autoimmunity among children of mothers who have type 1 diabetes. Conflicting results have been reported from short-term observations regarding the effect of breastfeeding on obesity of offspring."

From 1995 through 2000, women with GDM followed at a diabetes prenatal care clinic were asked to return for an anthropometric examination of their children between ages 2 and 8 years. The investigators collected data on maternal body mass index (BMI) before pregnancy, birth weight, and length, as well as weight and height of children and parents at the follow-up examination.

Of 324 children studied, 54% were boys and 46% were girls; 241 (74.4%) were breast-fed; and median duration of breast-feeding was 4.0 months (range, 0 - 20 months). Duration of breast-feeding was up to 3 months in 77 infants (23.8%) and more than 3 months in 164 infants (50.6%). Duration of breast-feeding was correlated negatively with prepregnancy maternal BMI (r = -0.197; P = .001). Of 85 obese mothers, 34 (40.0%) never breast-fed their infants compared with 49 (20.5%) of 239 nonobese women (P = .002).

At follow-up, mean age was 5.4 ± 1.6 years (range, 2.5 - 8.5 years). Of 324 children, 92 (28.4%) were overweight. BMI at follow-up was significantly negatively correlated with duration of breast-feeding (r = -0.130; P = .019). Prevalence of overweight status was 37.3% for non–breast-fed children, 32.5% for children breast-fed for up to 3 months, and 22.0% for children breast-fed for more than 3 months (P = .008).

Subgroup analyses revealed that childhood overweight status was significantly linked to breast-feeding duration in obese women (P = .042) but not in those with BMI less than 30 kg/m². Exclusive breast-feeding was an independent predictor of reduced risk for childhood overweight after adjustment for confounding factors, including parental obesity and high birth weight. These data suggest that the risk for childhood overweight may be reduced by 40% to 50% when breast-feeding is continued for more than 3 months.

"In children of mothers who have GDM, a population previously shown to have a high risk of infant overweight, we found that breast-feeding for >3 months appears to be negatively associated with overweight in early childhood," the authors write. "In our study, the prevalence of childhood overweight decreased with increased duration of nursing.... Women whose pregnancies were complicated by GDM, particularly those who are obese, should be encouraged to nurse for at least 3 months, since our data indicate that breast-feeding may be associated with childhood somatic development."

Novo Nordisk supported this study. The costs of publication of this article were defrayed in part by the payment of page charges, mandating that it must be marked "advertisement" solely to indicate this fact.