Premature labor is considered to be preterm when regular contractions occur between 28 and less than 37 weeks of gestation, but the cervix is not yet dilated and the cervical length is less than or equal to two centimeters as measured by vaginal ultrasound. Premature labor is also associated with a series of symptoms, such as hardening of the lower abdomen, small amount of vaginal bleeding, water breakage, and contractions. There are many reasons for preterm labor, including abnormal uterine development, history of preterm labor, physiological diseases, poor lifestyle, and genetic factors. If a woman has congenital dysplasia, such as an arcuate uterus or a bicornuate uterus, the probability of preterm labor rises to about 15-30%. If a woman has had a previous preterm birth, her second baby is twice as likely to be born prematurely as a normal woman. A range of conditions such as incompetence of the endocervix and infection of the lower reproductive tract can also cause preterm labor or even miscarriage. During pregnancy, smoking, alcohol consumption, overwork, mental tension and psychological stress can increase the probability of preterm labor. In addition, preterm labor is also related to genetic factors, and familial preterm labor can increase the probability of preterm labor in women. There are many factors that can cause preterm labor. The actual fact is that you can find a lot of people who are not aware of the fact that they are not in a good position to be able to get to the hospital in time for delivery.