The four-month-old fetus has already differentiated its human form, and all organs have begun to develop, so that the nose, mouth, eyes and other parts of the body can be clearly seen. At four months of pregnancy, when the mother is in the mid-pregnancy state, the fetus has begun to take on a human shape, the length of the body is usually about 12 to 16 centimeters, the fetus can distinguish the sex, the head is relatively more obvious, the hair grows out, the nose, mouth, eyes can be seen, and already has a respiratory function. Four-month-old fetus grows and develops faster and requires higher nutrition. At this stage, pregnant women generally have a better appetite, and their diet must be more nutritious, with more foods rich in high-quality proteins and calcium, such as milk, eggs, beef, and so on. In addition, during pregnancy must pay attention to regular obstetric examination, especially pay attention to timely do Down’s syndrome screening, system ultrasound detector examination.