Aldrete Cortez, Vania RocíoVania RocíoAldrete CortezPerapoch, JosephJosephPerapochPoblano, AdriánAdriánPoblano2023-01-252023-01-252015https://scripta.up.edu.mx/handle/20.500.12552/231910.1016/j.earlhumdev.2015.09.013Dear Editor Recently we read the papers by Neu et al. and Mörelius et al. [1], [2]. Their research documented cortisol co-regulation between mothers and infants during skin to skin care (SSC). Even though both studies' results exhibited lower cortisol levels, in one study with marginal differences [1] and in the other, with significant differences [2] between a group of premature infants SSC treated, as compared to the standard care (SC) group, only Mörelius et al. found cortisol co-regulation at four months of age, as an index of neuro-endrocrine effect of SSC [2]. ©Early Human DevelopmentResource Types::text::journal::letter to the editor