Prenatal evaluation and postnatal outcomes of fetal ovarian cysts.

OBJECTIVES: To evaluate the natural history and outcome of cases of fetal ovarian cyst under conservative prenatal treatment. METHODS: A retrospective cohort study included patients diagnosed with fetal ovarian cysts was conducted between January 2008 to December 2016. Data including clinical data, sonographic feature and postnatal outcomes were obtained. RESULTS: 102 cases were included for statistical analysis. The rate of spontaneous resolution was significantly higher among cases with simple than complex cysts (70/92 or 76.1% vs 2/10 or 20%, P < 0.01) and for cysts <4 cm than cysts ≥4 cm (50/56 or 89.3% vs 22/46 or 47.8%, P < 0.01). Ovarian torsion was confirmed in 5/102 (4.9%) cases; neither prenatal characteristics of cysts (complex: 2/10 or 20% vs simple: 3/92 or 3.3%, P = 0.07), nor their size (≥ 40 mm: 4/46 or 8.7% vs < 40 mm: 1/56 or 1.8%, P = 0.17) was predictive for ovarian torsion. 25/102 (24.5%) of cysts change in size or sonographic characteristics prenatally. Half of the complex cysts at the last prenatal scan are not ovarian in origin. 98/102 neonates (96.1%) were able to preserve both ovaries. CONCLUSIONS: Spontaneous resolution of ovarian cysts is predicted by cyst size and characteristics, whereas likelihood of torsion cannot be predicted.