Effect of Breastfeeding Duration on Coagulation in Women With and Without History of Gestational Diabetes Mellitus.

Context: Breastfeeding is associated with a reduced maternal risk for cardiovascular diseases (CVDs).

Objective: Since the underlying mechanisms are still poorly understood, we here examined the effect of breastfeeding on the plasmatic coagulation system in women with and without history of gestational diabetes mellitus (GDM).

Methods: A total of 76 participants of the German Gestational Diabetes Study (PREG; NCT04270578) were examined 14 months (interquartile range [IQR], 12-26 months) after delivery with a 5-point oral glucose tolerance test. Global coagulation tests, prothrombotic coagulation proteins (FII/FVII/FVIII/FIX), antithrombotic proteins (antithrombin, protein C/S), and endothelial markers (von Willebrand factor and plasminogen activator inhibitor 1) were determined. The Framingham risk score was used to estimate the 10-year CV risk. The effect of breastfeeding duration on coagulation was analyzed using multivariable linear models.

Results: The mean duration of breastfeeding was 11 months (IQR, 7-14 months). Overall, longer duration of breastfeeding was associated with lower CV risk (Framingham risk score; P = .05) and was negatively associated with FIX (P = .018). We detected an interaction between previous GDM and breastfeeding duration for FIX (PInteraction = .017): Only in women with GDM history was the duration of breastfeeding negatively associated with FIX activity (P = .016). This association persisted in statistical models adjusted for age, body mass index, insulin sensitivity, and C-reactive protein. The duration of breastfeeding was not associated with anticoagulant proteins and endothelial markers.

Conclusion: Longer duration of breastfeeding is associated with lower CV risk and an improved coagulation profile. Women with GDM history appear to benefit particularly from prolonged breastfeeding.