Outcome of fetal ovarian cysts diagnosed on prenatal ultrasound examination: systematic review and meta-analysis

Objective: To explore the outcome of fetuses with a prenatal diagnosis of ovarian cyst. Methods: The electronic databases MEDLINE and EMBASE were searched using keywords and word variants for ‘ovarian cysts’, ‘ultrasound’ and ‘outcome’. The following outcomes in fetuses with a prenatal diagnosis of ovarian cyst were explored: resolution of the cyst, change of ultrasound pattern of the cyst, occurrence of ovarian torsion and intracystic hemorrhage, need for postnatal surgery, need for oophorectomy, accuracy of prenatal ultrasound examination in correctly identifying ovarian cyst, type of ovarian cyst at histopathological analysis and intrauterine treatment. Meta-analyses using individual data random-effects logistic regression and meta-analyses of proportions were performed. Quality assessment of the included studies was performed using the Newcastle–Ottawa Scale. Results: Thirty-four studies (954 fetuses) were included. In 53.8% (95% CI, 46.0–61.5%) of cases for which resolution of the cyst was evaluated (784 fetuses), the cyst regressed either during pregnancy or after birth. The likelihood of resolution was significantly lower in complex vs simple cysts (odds ratio (OR), 0.15 (95% CI, 0.10–0.23)) and in cysts measuring ≥ 40 mm vs < 40 mm (OR, 0.03 (95% CI, 0.01–0.06)). Change in ultrasound pattern of the cyst was associated with an increased risk of ovarian loss (surgical removal or autoamputation) (pooled proportion, 57.7% (95% CI, 42.9–71.8%)). The risk of ovarian torsion was significantly higher for cysts measuring ≥ 40 mm compared with < 40 mm (OR, 30.8 (95% CI, 8.6–110.0)). The likelihood of having postnatal surgery was higher in patients with cysts ≥ 40 mm compared with < 40 mm (OR, 64.4 (95% CI, 23.6–175.0)) and in complex compared with simple cysts, irrespective of cyst size (OR, 14.6 (95% CI, 8.5–24.8)). In cases undergoing prenatal aspiration of the cyst, rate of recurrence was 37.9% (95% CI, 14.8–64.3%), ovarian torsion and intracystic hemorrhage were diagnosed after birth in 10.8% (95% CI, 4.4–19.7%) and 12.8% (95% CI, 3.8–26.0%), respectively, and 21.8% (95% CI, 0.9–40.0%) had surgery after birth. Conclusion: Size and ultrasound appearance are the major determinants of perinatal outcome in fetuses with ovarian cysts.