Changes during pregnancy affect negatively or positively the fetus and his entire remaining course. Aim: The aim of the present study was to show the relationship between the pregnant woman and the formation of the psychology of the fetus. Method and Material: The methodology of this study includes bibliography research from both the review and the research literature on PubMed, Cinahl and PsycINFO databases (1990-2011) which refers to the factors that affect the fetus’ psychology. The keywords that were used were the following: “prenatal psychology”, “fetus psychology”, “pregnancy”, “stress”. Results: According to the bibliography, the negative intentions of being pregnant and stress during pregnancy have been associated with low-birth weight, pre-term birth, emotional and behavioral development of the child. Conclusions: If the pregnant woman keeps her balance then it is of great importance for the fetus, as if any disorder during prenatal and perinatal period can influence it negatively. On the contrary, the normal communication between the mother and the fetus is decisive for his normal development.