Diagnosis, Management, and Therapy of Fetal Ovarian Cysts Detected by Prenatal Ultrasonography: A Report of 36 Cases and Literature Review

Background: Fetal ovarian cysts are the most frequently diagnosed intra-abdominal cysts; however, the evidence for perinatal management remains controversial. Methods: We retrospectively reviewed cases of fetal ovarian cysts diagnosed by prenatal ultrasonography at our institution between January 2010 and January 2020. The following were investigated: gestational age at diagnosis, cyst size, appearance, prenatal ultrasound findings, and postnatal outcomes. Prior to 2018, expectant management was applied in all cases; after 2018, in utero aspiration (IUA) of simple cysts ≥40 mm was performed. Results: We diagnosed 29 and seven simple and complex cysts, respectively. Fourteen patients had simple cysts with a maximum diameter <40 mm, and two of them progressed to complex cysts during follow-up; however, when the diameter was limited to <35 mm, no cases showed progression to complex cyst. Fifteen of the simple cysts were ≥40 mm; three progressed to complex cysts, and two of them were confirmed to be ovarian necrosis. In four patients who underwent IUA, the ovaries could be preserved. Conclusions: IUA is a promising therapy for preserving ovaries with simple cysts ≥40 mm in diameter; however, the indications for fetal surgery and the appropriate timing of intervention require further study.