The common causes of preterm labor are as follows: First, if there is premature rupture of membranes or amniotic membrane infection during pregnancy, it may cause preterm labor. Secondly, if the original gynecological diseases recur during pregnancy, such as vaginitis, pelvic inflammatory disease, endometritis and other diseases, and they are not treated in time, it may cause preterm labor. Thirdly, if the mother has diseases during pregnancy, it may also cause preterm labor, such as gestational diabetes, hypertension and other problems, and if the pregnant woman is under too much mental stress during pregnancy, or stimulated by external factors may cause this situation. It is advisable to pay more attention to rest during pregnancy, preferably without excessive psychological stress, to do a good job of health care and personal hygiene, to wash the pubic area with warm water every day, to prevent gynecological diseases, and to actively treat pregnancy complications.