Background. Human Milk (HM) is a dynamic nourishment: its composition is influenced by several conditions such as gestational age, maternal diet and ethnicity. It appears important evaluate the impact that gestational diseases have on HM components and if their presence, as source of oxidative stress in the mother, influence milk’s redox homeostasis. To assess Preeclampsia (PE) and Gestational Diabetes Mellitus (GDM) effect on milk’s total oxidative load, we chose to investigate both oxidative and antioxidant aspects, with respectively Lipid hydrop-eroxides (LOOHs) and Glutathione (GSH)). Methods. GSH and LOOHs were quantified using an ELISA test. To investigate the effect of pathology on redox homeostasis, mixed linear model with unistructural covariance structure was performed. Results. A total of 120 mothers were re-cruited. The GSH concentration results significant lower in GDM women than in healthy only in colostrum (p<0.01). No other differences emerged. LOOHs was not detectable in almost all the samples. Discussion. Our study is the first to extensively evaluate these components in the HM of women with these gestational pathologies. The main observation is that GDM can alter the anti-oxidant composition of HM mainly in colostrum, but in case of PE, the composition of HM milk is preserved.