This article discusses a peculiar case of a fetal ovarian cyst discovered during a routine third-trimester ultrasound examination. The ultrasound characteristics of the cyst were described as having a "pearl in a shell" appearance, with a central hyperechogenic formation resembling a blood clot. The cyst gradually reduced in size during the pregnancy and disappeared completely after birth. The article emphasizes the importance of postnatal follow-up for prenatal ovarian cysts, as they often undergo spontaneous reabsorption. The management of ovarian cysts during pregnancy is not standardized, and the need for surgery varies depending on the center and prenatal findings.