Outcome Analysis of Fetal Ovarian Cysts: A Single Center Experience.

Objective: To analyze the ultrasound manifestations of ovarian cysts with different outcomes and explore the postnatal characteristics of fetal ovarian cyst torsion.

Methods: A total of 74 cases of fetal ovarian cysts identified among 137 358 fetuses undergoing prenatal ultrasound examination and postnatal management in our hospital from January 2016 to September 2024 were retrospectively analyzed. Among them, 15 cases underwent postnatal ultrasound review and surgical confirmation. Based on the surgical results, these cases were divided into three groups: four cases of simple ovarian cysts (Simple Group), four cases of hemorrhagic ovarian cysts (Hemorrhage Group), and seven cases of ovarian cyst torsion (Torsion Group). The prenatal and postnatal sonographic features of these three groups were summarized and compared.

Results: The simple group showed thin, smooth walls and good internal echogenicity on both prenatal and postnatal ultrasound. The torsion group and hemorrhage group exhibited complex cystic features on prenatal ultrasound, lacking specific characteristics. Postnatal ultrasound in the torsion group, in addition to the features of complex cysts, also showed residual ovarian stromal edema, the "Squasar" sign, and/or changes in cyst position.

Conclusions: It is difficult to differentiate between hemorrhagic ovarian cysts and ovarian cyst torsion during fetal development. Immediate postnatal ultrasound review is necessary. The presence of residual ovarian stromal edema, the "Squasar" sign, or changes in cyst position should raise a high suspicion of ovarian cyst torsion.