Lactation intensity and postpartum maternal glucose tolerance and insulin resistance in women with recent GDM: the SWIFT cohort

Diabetes Care. 2012 Jan;35(1):50-6. doi: 10.2337/dc11-1409. Epub 2011 Oct 19.


Objective: To examine the association between breastfeeding intensity in relation to maternal blood glucose and insulin and glucose intolerance based on the postpartum 2-h 75-g oral glucose tolerance test (OGTT) results at 6-9 weeks after a pregnancy with gestational diabetes mellitus (GDM).

Research design and methods: We selected 522 participants enrolled into the Study of Women, Infant Feeding, and Type 2 Diabetes (SWIFT), a prospective observational cohort study of Kaiser Permanente Northern California members diagnosed with GDM using the 3-h 100-g OGTT by the Carpenter and Coustan criteria. Women were classified as normal, prediabetes, or diabetes according to American Diabetes Association criteria based on the postpartum 2-h 75-g OGTT results.

Results: Compared with exclusive or mostly formula feeding (>17 oz formula per 24 h), exclusive breastfeeding and mostly breastfeeding (≤6 oz formula per 24 h) groups, respectively, had lower adjusted mean (95% CI) group differences in fasting plasma glucose (mg/dL) of -4.3 (-7.4 to -1.3) and -5.0 (-8.5 to -1.4), in fasting insulin (μU/mL) of -6.3 (-10.1 to -2.4) and -7.5 (-11.9 to -3.0), and in 2-h insulin of -21.4 (-41.0 to -1.7) and -36.5 (-59.3 to -13.7) (all P < 0.05). Exclusive or mostly breastfeeding groups had lower prevalence of diabetes or prediabetes (P = 0.02).

Conclusions: Higher intensity of lactation was associated with improved fasting glucose and lower insulin levels at 6-9 weeks' postpartum. Lactation may have favorable effects on glucose metabolism and insulin sensitivity that may reduce diabetes risk after GDM pregnancy.

Publication types

  • Research Support, N.I.H., Extramural

MeSH terms

  • Adult
  • Blood Glucose / metabolism
  • Bottle Feeding / statistics & numerical data
  • Breast Feeding / statistics & numerical data*
  • California / epidemiology
  • Cohort Studies
  • Diabetes Mellitus, Type 2 / epidemiology
  • Diabetes, Gestational / physiopathology*
  • Female
  • Glucose Intolerance / epidemiology*
  • Glucose Tolerance Test
  • Humans
  • Infant
  • Infant, Newborn
  • Insulin / blood
  • Insulin / physiology
  • Insulin Resistance / physiology*
  • Lactation / physiology*
  • Middle Aged
  • Pregnancy
  • Prevalence
  • Prospective Studies


  • Blood Glucose
  • Insulin