The "Bad Father": Paternal Role in Biology of Pregnancy and in Birth Outcome

Simple Summary Human reproduction, as well as that of all mammals, involves the union of two cells, the male sperm and the female egg, which give rise to a new organism that will grow for about 280 days inside the mother's body. Most research on pregnancy, its complications, and diseases of the unborn child and newborn has focused, appropriately enough, on maternal conditions and the interaction between mother and child, leaving the father with only the role of depositing his genetic material at the moment of conception. This study aims to compile the research that has dealt with the father's role in determining a good or bad course of pregnancy and birth. From this perspective, the father can be a "good father" or a "bad father" not only because of his hereditary genetic heritage, but also because of how he lives, how he feeds, and how he eats; in short, if a man takes care of his health, he is already taking care of his children's health.Abstract Pregnancy is generally studied as a biological interaction between a mother and a fetus; however, the father, with his characteristics, lifestyle, genetics, and living environment, is by no means unrelated to the outcome of pregnancy. The half of the fetal genetic heritage of paternal derivation can be decisive in cases of inherited chromosomal disorders, and can be the result of de novo genetic alterations. In addition to the strictly pathological aspects, paternal genetics may transmit thrombophilic traits that affect the implantation and vascular construction of the feto-placental unit, lead to placenta-mediated diseases such as pre-eclampsia and fetal growth retardation, and contribute to the multifactorial genesis of preterm delivery. Biological aspects of immunological tolerance to paternal antigens also appear to be crucial for these pathologies. Finally, this review describes the biological findings by which the environment, exposure to pathogens, lifestyle, and nutritional style of the father affect fetal pathophysiological and epigenetic definition.