The mood of a pregnant woman has an impact on her fetus. It is known that when the mother’s mood changes, it can stimulate the activity of her vegetative nervous system, so the endocrine glands controlled by the nervous system will secrete a variety of hormones. These hormones can pass through the blood circulation to the placenta, causing changes in the blood composition of the placenta and thus stimulating the activity of the fetus. If a pregnant woman is often emotionally irritable during pregnancy, this may result in smaller changes in the child’s heart rate after birth. Studies have found that when a pregnant woman is often angry during pregnancy, the hormonal changes in her body can also be transmitted to the fetus through the placenta, thus affecting the fetus’ cell development. In addition, if a pregnant woman is emotionally overstressed for a long time, such as anger, fear, pain, shock, worry, etc., it may have a negative impact on the hypothalamus of the fetus, resulting in a greater chance of mental illness later in life.