A closer look at fetal development at two months In the early stages of pregnancy, the embryo transforms into a fetus and begins to go through many important developmental stages. At two months of age, your baby is developing rapidly and going through some important changes. The following will elaborate on the fetal development at this stage from four aspects. Formation of body structures and organs Around six weeks into pregnancy, the fetus\’s heart begins to beat. By two months, the heart has formed a complete set of four atria and ventricles, and can be detected by ultrasound.