It is uncertain whether pregnancy with an endometriosis cyst has any effect on the fetus; if the cyst is large, or if there are complications, it often has an effect on the fetus. Endometriosis has some effect on pregnancy, not much effect on the fetus. However, when a patient has an ovarian endometriosis cyst, it is necessary to determine whether the cyst has any effect on the fetus, depending on the size of the cyst. When endometriosis cysts are large, they may affect the enlarged uterus and the fetus, such as causing miscarriage in early pregnancy, preterm labor in late pregnancy, and preventing the head of the fetus from entering the pelvis during delivery. In addition to taking up space, there is also the possibility of ovarian cysts with torsion of the tip and rupture of the cysts, and other acute abdominal conditions that require surgical intervention in pregnancy, thus affecting the fetus. Patients who are pregnant and found to have endometriosis cysts, need to consult a doctor in a timely manner, need to comply with the doctor’s instructions regular obstetric examination and treatment.