Amniotic fluid leakage may occur in the middle of pregnancy under normal conditions. Leakage of amniotic fluid is medically known as premature rupture of membranes and normally occurs before labor. Leakage of amniotic fluid can occur in the middle of pregnancy due to various external factors. If it occurs in the middle of pregnancy, it is necessary to go to the hospital for ultrasound and vaginal fluid smear to help identify the cause, and the common causes are as follows: 1. Reproductive tract infections: anaerobic bacteria, Neisseria gonorrhoeae, chlamydia are common pathogens that cause reproductive tract infections. If pregnant women do not pay attention to perineal hygiene or have an unclean sex life, the reproductive tract will be susceptible to infections and lead to a decrease in the local tension of the fetal membranes, causing premature rupture of the membranes. 2. Trauma: If the abdomen is impacted during pregnancy, or frequent sexual intercourse, premature rupture of membranes will be easily caused. 3. Abnormal amniotic membrane pressure: if the pregnant woman has excessive amniotic fluid or is a twin pregnancy, it is easy to make the pressure in the uterine cavity too large and increase the risk of premature rupture of membranes; at the same time, if it is in a transverse position, head-first exposure and other fetal position anomalies, it is easy to lead to uneven pressure on the fetal membranes, which is also easy to rupture the membranes prematurely. Therefore, amniotic fluid leakage may occur in the middle of pregnancy, and if amniotic fluid leakage occurs in the middle of pregnancy, timely diagnosis and treatment should be made to avoid affecting the outcome of pregnancy.