Introduction
Gestational diabetes mellitus (GDM) is diagnosed on the basis of
hyperglycemia first detected at any time during
pregnancy.1 There is a global rise in the incidence of
GDM, with current rates documented to be between 5–36% of pregnant
women, dependent on the population, screening and diagnostic
criteria.2-4 A significant individual burden is
associated with GDM for women and their families including adverse
perinatal outcomes, psychological impact and long-term cardiometabolic
health consequences.5, 6 There is a growing awareness
of the rising worldwide economic implications for health service
delivery associated with GDM.7 It is important to
identify modifying factors that can reduce GDM and improve pregnancy
outcomes for women and infants through targeted use of health resources.
The benefits of breastfeeding to infants are well documented8 and have resulted in ongoing programs worldwide to
improve breastfeeding rates. However, less attention has been given to
the maternal benefits. Increasing evidence suggests that breastfeeding
intensity and the total length of time a woman breastfeeds during her
life can positively influence her health. This includes a reduction in
type 2 diabetes and an improved cardiometabolic risk
profile.9-14
Information is lacking on how breastfeeding length and intensity may
impact on glycemic control and the development of GDM in a subsequent
pregnancy for women who have had hyperglycemia in a prior pregnancy.
Women who have GDM in their first pregnancy may have up to a 13-fold
increased risk of GDM in their second pregnancy.15-17Every subsequent pregnancy after a GDM-affected pregnancy has a
compounding risk of GDM and a progression to type 2
diabetes.17, 18 We are unaware of any research that
has investigated whether breastfeeding reduces this between-pregnancy
cumulative risk for the development of GDM. The aim of our breastfeeding
length intensity in gestational diabetes (BLIiNG) study is to
investigate women who have had GDM in their first pregnancy and assess
if length and intensity of breastfeeding mediates GDM risk in a
subsequent pregnancy.