During the first month of pregnancy, the major sections of the fetus are developing. The fetal body prioritizes the creation of vital tissues, such as blood, to facilitate further development later in pregnancy. The placenta, which allows the baby to obtain nutrients from the mother’s blood, also develops during this time. After the first month, the baby is usually the size of a single grain of rice.The second month of pregnancy is devoted to completing the neural tube, an area of tissue where the nervous system originates. Facial features, such as ears, start to form. The baby develops buds of tissues that eventually become limbs. The digestive tract also begins to form. After this month, the baby is already around an inch long.Most substantial parts of the baby have structure during the third month of pregnancy. At the end of this period, the fetus bears a striking resemblance to a newborn. The baby can already make movements. The reproductive organs also start developing at this stage. After the third month, the baby is already up to four inches long.