The feeling of dysmenorrhea from time to time in pregnant women may be due to preterm labor, or it may be due to diseases, such as preterm labor, placental abruption, and so on. Generally occurs with preterm labor, the fetus is descending, the abdomen and waist will have a feeling of fullness and pressure, but also produces waiting pregnant women to appear similar to menstrual cramps. Generally short duration, weak intensity, long and irregular intervals, can cause lower abdominal pain similar to dysmenorrhea. The above is normal after full-term pregnancy. In the case of a pregnant woman who is not yet full-term, preterm labor with precocious labor has occurred, and there may be vaginal bleeding, which requires prompt medical attention. Placental abruption may also occur with persistent lower abdominal pain, which may be disproportionate to the size of the abruption and the amount of blood accumulated behind the placenta. Pregnant women in labor who experience intermittent menstrual cramps are advised to seek prompt medical attention, follow the doctor’s instructions for further examination, and choose a reasonable treatment plan under the doctor’s comprehensive analysis.