A prospective controlled study assessing postpartum breastfeeding in women with type 2 diabetes: lower rates associated with elevated BMI rather than diabetes.

AIMS/HYPOTHESIS: Breastfeeding is associated with metabolic benefits for women with type 2 diabetes and their infants, yet breastfeeding rates in these women are poorly described. Obesity is associated with type 2 diabetes and lower breastfeeding rates, making it difficult to disentangle the effects of type 2 diabetes vs obesity on breastfeeding. The primary objective was to examine breastfeeding rates in women with type 2 diabetes compared with normoglycaemic women with either (1) matched BMI or (2) normal BMI. The secondary objective was to examine variables associated with breastfeeding.

METHODS

Pregnant women with type 2 diabetes (cases) or normoglycaemia (controls) were prospectively recruited. Each case was matched with two controls by age and parity and either (1) matched or (2) normal (18-25 kg/m2) BMI. Data were collected from in-person surveys antenatally, medical records and a 4 month postpartum telephone survey. Analysis included descriptive and inferential statistics.

RESULTS

Four months of breastfeeding data were available for 29 women with type 2 diabetes, 29 BMI-matched controls and 28 normal-BMI controls. Breastfeeding rates were similar in women with type 2 diabetes and BMI-matched controls, but both rates were significantly lower than those in normal-BMI controls. 'Full' breastfeeding rates were 24%, 38% and 64% in women with type 2 diabetes, BMI-matched controls and normal-BMI controls, respectively, and were not different between women with type 2 diabetes vs BMI-matched controls (p=0.26) but were lower in women with type 2 diabetes vs normal-BMI controls (p=0.002). 'Any' breastfeeding rates were 55%, 54% and 82% in women with type 2 diabetes, BMI-matched controls and normal-BMI controls, respectively, again showing no difference between women with type 2 diabetes vs BMI-matched controls (p=0.79) but were lower in women with type 2 diabetes vs normal-BMI controls (p=0.03).

CONCLUSIONS/INTERPRETATION: Maternal obesity, rather than type 2 diabetes, may be the major determinant of reduced breastfeeding rates 4 months postpartum.