The fetus may defecate in the pregnant woman’s stomach, which is usually caused by the maturity of the fetus’s intestinal function, the fetus’s lack of oxygen in the uterus and other conditions. 1. Maturity of intestinal function: when the gestational week is relatively large, the intestinal function of the fetus gradually develops and matures, and the probability of the fetus defecating will increase. 2. Intrauterine hypoxia: when the fetus has hypoxia in the uterus (e.g., intrahepatic cholestasis in pregnancy causes constriction of the placental intervillous blood vessels, which leads to hypoxia), the bowel movement will be stronger, which will lead to defecation problems. It is important to note that when defecation is detected in the fetus, it is important to increase monitoring and closely observe the fetal heart to reduce the probability of the fetus developing conditions such as aspiration pneumonia. In addition, during pregnancy, for the safety of herself and her fetus, pregnant women should do obstetric examination on time.