Prenatal diagnosis of ovarian cyst

Abstract

Introduction: The prenatal diagnosis of a fetal abdominal cyst raises the following possibilities: mesenteric cysts, obstructive uropathy with dilated ureter, intestinal duplication and ovarian cysts when the fetus is female. Ovarian cysts have been described in association with diabetes mellitus, alloimmunization and fetal hypothyroidism, but the etiology is often unknown. In normal pregnancies, the development of ovarian cysts has been attributed to hormonal stimuli due to immaturity of the neuro–endocrine axis. A possible mechanism involves gonadotropin elevation that stimulates fetal foliculogenesis and the development of cysts. Management is usually expectant since most cysts resolve spontaneously after birth. However, complications such as rupture or torsion of the cyst can lead to destruction of this organ. Drainage is indicated when the diameter is greater than 5 cm or there signs suggestive of internal hemorrhage, such as internal septa or echogenic debris. N.M.F., a 31‐year‐old, first pregnancy, had an ultrasound scan at 22‐weeks which showed no fetal abnormalities. At 30 weeks, repeat scan showed an abdominal cyst between the bladder and the right kidney measuring 4.3 cm × 4.2 cm × 3.8 cm in a female fetus. Two weeks later, it became larger (6.3 cm × 5.5 cm × 5.4 cm) and drainage was performed with aspiration of 50 mL of sero‐sanguineous fluid. Progesterone levels in the aspirated fluid were 17 000 ng/dL and estrogen levels, 1350 ng/dL; these findings confirmed the hypothesis that it was an ovarian cyst. This case highlights the need to perform follow up scans when a fetal abdominal cyst is diagnosed and the importance of intrauterine drainage as a diagnostic and therapeutic tool to preserve ovarian function.