Diagnosis of a Large Vaginal Cyst During Pregnancy.

In this report, we detail an unusual presentation of a large Müllerian cyst during pregnancy. A primigravida woman, 25 weeks and 6 days pregnant, arrived at the Obstetrics and Gynecology Emergency Department at Qatif Central Hospital, Saudi Arabia, complaining of something protruding from her vagina, accompanied by a yellowish vaginal discharge and mild back pain. After a series of initial examinations and tests, the patient was diagnosed with cervical incompetence and prolapsed fetal membranes, indicating a threat of preterm labour.