In the 5th month of pregnancy, the phenomenon of hard stomach is considered to be caused by pseudocontractions. Pseudocontractions during this period are usually not painful or regular and will be relieved after rest. If there is hardness in the belly, accompanied by pain or bleeding, it should be considered a sign of miscarriage, so it is best to go to the hospital to have an ultrasound examination, and then carry out treatment to preserve the pregnancy. During this period, try to pay attention to bed rest, do not exercise strenuously, or walk, and also need to pay attention to not have too much stress. If you are too nervous, it will easily lead to uterine contraction and increase the chance of miscarriage. If you have a miscarriage, you should use birth control medication as soon as possible to keep the fetus alive, and you should also pay attention to the change of fetal heartbeat and fetal movement during this period.