[The mother-infant encounter at birth must be protected].

The medical decision to separate a newborn baby from his or her mother is frequent. This medical practice must be evaluated. The scientific literature regarding humans and other mammals was reviewed in order to describe the physiology of the interactions between mother and offspring and the consequences of disrupting their interactions around birth. Mother-infant bonding is common to all mammals. Attachment is the result of three mechanisms: behavioral programing, secretion of neuroendocrine substrates, and activation of sensory cues. Breastfeeding is a fourth component that plays a crucial role. Experimental research provides evidence that early-life maternal separation can alter biological responses to stress, disturb learning behaviors, and impair social skills. Recent advances in epigenetic research may partly explain how neonatal maternal deprivation at birth can lead to biological and behavioral disorders in adulthood. Therefore, the decision to separate a newborn infant from his or her mother is not harmless and must be carefully considered. In order to better take into account these data, the organization of perinatal care in France should be revised.