A cystic mass in the left adnexal area during pregnancy may be ectopic pregnancy, and further examination is recommended to determine its nature. Ectopic pregnancy is also known as ectopic pregnancy, when the fertilized egg grows in the fallopian tube, ovary and other parts of the body, there may be a cystic mass in the adnexal region, which requires a urine or blood hCG test. If the HCG test is positive and lower than the normal pregnancy level, and there is no intrauterine pregnancy on ultrasound, and the gestational sac, germ and fetal heart are detected in the uterine parietal, then the diagnosis of ectopic pregnancy can be confirmed. If the results of the above tests are negative, other types of adnexal cysts, such as tubal cysts or ovarian cysts, may be related to endocrine disorders, pelvic infections, follicular abnormalities and other reasons, and then gynecological ultrasound can be performed to determine the location and nature of the cysts. Since the cystic mass in the left adnexal area during pregnancy may be caused by many factors, it is recommended to go to the hospital for further examination to clarify the diagnosis and actively carry out appropriate treatment.