Fetal development: The fetus at four months of pregnancy has taken shape, is about the size of a palm, and weighs about 25 grams. At this time, the baby\’s organs and body structure are relatively mature and can carry out basic movements and activities. In addition, the gender of the fetus has been basically determined. During this stage, the fetus\’s brain, nervous system, respiratory system, kidneys and other organs continue to develop and gradually adapt to the nutrients and oxygen provided by the mother. Fetal nutritional needs