1. Fetal size at two months of pregnancy At two months of pregnancy, the size of the fetus is about the size of a bean and about 1.5 centimeters long. At this time, the fetus has begun to form its head, body, and limbs, and organs such as the heart, liver, and kidneys have also begun to develop. 2. The development of the fetus at two months of pregnancy. During the second month of pregnancy, the fetus develops very rapidly. At this time, the fetus\’s nerves have begun to develop, and breathing and digestion are also developing.