At 38 weeks, the fetus is mature in all organs and systems and has the function to survive independently. The fetus is about 52cm long and weighs about 3200g at 38 weeks of pregnancy. The head of the fetus is completely in the pelvis, the average biparietal diameter is 9.08±0.59cm, the average abdominal circumference is 30.63±2.83cm, and the femur length is 7.20±0.43cm. At this time, the nails of the fetus’ fingers and toes have grown, and the hair has grown to about 2cm. The original layer of fine villi and most of the white fetal fat on the fetus is gradually shed, and the skin wrinkles gradually disappear and become smooth. The fetus swallows the secretions and the material that is gradually shed along with the amniotic fluid and gradually turns into black “fetal stool” in the intestine, which is excreted after the birth of the fetus. At this time, pregnant women may have hyperemesis, edema of hands and face, feet and ankles, and frequent urination due to the pressure of the fetal head into the pelvis. The fetus is fully developed at 38 weeks and can be born healthy at any time.