The lower abdominal cramping in the fifth month of pregnancy may be caused by the growth of the uterus, the right rotation of the uterus, or it may be a pre-eclampsia miscarriage, which needs to be combined with other symptoms such as the presence of vaginal bleeding to make a comprehensive judgment. Mainly for the following reasons: 1, uterine growth: five months of pregnancy, the fetus grows faster, the uterus will grow, the process of uterine growth, there will be a slight feeling of lower abdominal cramps or tingling, generally not particularly obvious, is a normal performance; 2, uterine right rotation: five months of pregnancy, most of the uterus in a right-handed state, the increased uterus compression of the inferior vena cava, affecting the venous reflux, perineal congestion The lower abdominal cramps are more obvious when standing or squatting for a long time. It is recommended to avoid standing or squatting for a long time, pay attention to bed rest, try to take a left-sided position, appropriate elevation of the lower limbs to promote blood return, to relieve the symptoms of discomfort; 3, pre-eclampsia abortion: five months of pregnancy, lower abdominal cramps continue or gradually aggravate, into pain, accompanied by vaginal bleeding, may have occurred pre-eclampsia abortion. It is recommended to seek medical attention promptly, perform ultrasound examination to clarify the diagnosis, pay attention to bed rest, and may take oral medication for fetal preservation treatment.