The love-shaper: role of the foetus in modulating mother-child attachment through stem cell migration to the maternal brain

Background Foetal PAPCs (pregnancy-associated progenitor cells) begin to cross the placenta in a scheduled manner from early pregnancy and colonise many maternal organs, both in mammals and humans, during each pregnancy. The maternal limbic system appears to be colonised with a 100% frequency when compared with other maternal organs. Once they arrive in the limbic system, foetal PAPCs differentiate into neurons and glial cells, resulting in the formation of new synapses with and among maternal neurons. This process is accompanied by major structural neurobiological alterations orchestrated by hormonal changes characteristic of gestation and involves the limbic system, reward areas, and other closely connected brain structures, i.e., the same areas colonised by foetal PAPCs.Objective To correlate findings regarding microscopic and macroscopic changes induced by foetal stem cell migration into the maternal limbic system and hormonal surges during pregnancy with the biological basis of mother-child attachment dynamics, with a focus on the clinical implications this discovery has for normal, complicated, and assisted pregnancies.Evidence review A literature review of evidence regarding the neuroanatomical correlation between the targeted, colonising migration of foetal PAPCs into the maternal brain and the structural neurobiological alterations within the affective areas related to attachment and reward was conducted.Results and Conclusions These findings suggest a synergic effect of cellular and morphological changes, with a common biological aim of conferring an adaptive advantage in motherhood, and with the foetus playing a surprisingly active role in modulating the mother's ability to love and care for it.