The tightness and hardness of the stomach in the fourth and a half months of pregnancy should be caused by physiological uterine contractions. At four and a half months, when the fetus is growing, the uterus will also increase in size, resulting in increased sensitivity of the uterus, and when the fetus moves within the uterine cavity with too large a range of motion, it will lead to uterine contractions. Uterine contractions can also be caused by external stimuli, and this condition does not require special treatment. During this period of time, gently stroking the belly or kneeling on the bed can reduce the degree of tension in the abdominal wall, can reduce the phenomenon of tight and hard stomach, usually should try to pay attention to rest, do not overwork, keep a relaxed mood, do not have too much pressure. If the pressure is too great, it will not only affect the growth and development of the fetus, but also easily lead to uterine contraction, increasing the chance of miscarriage.