Abstract
OBJECTIVE: This study aimed to evaluate the perinatal outcome of fetal abdominal cysts based on the timing of prenatal diagnosis and identify prenatal characteristics associated with postnatal surgical intervention. METHODS: Fetuses with prenatally detected isolated abdominal cysts referred between January 2007 and December 2022 were included. Fetuses with multiple congenital anomalies or cysts suspected of renal or spinal origin were excluded. RESULTS: Among the 253 included cases, 67.6% (171/253) of the abdominal cysts regressed spontaneously either prenatally or postnatally. Persistent cysts were observed during postnatal follow-up in 28.9% (73/253) and in 3.6% (9/253) the suspected abdominal cyst was reclassified as another anomaly during postnatal follow-up. Two cases of a transient cyst diagnosed in the first trimester required surgical intervention postpartum. Surgical intervention was performed in 16.2%. Multivariate analysis showed that prenatal cysts > 40 mm were strongly associated with surgical intervention (OR 10.25, 95% CI 4.08-25.74). Diagnosis before 16 weeks (OR 5.03, 95% CI 1.04-24.42) and between 16 and 24 weeks (OR 6.42, 95% CI 2.49-16.51) was also linked to higher odds of surgery compared with diagnosis after 24 weeks, whereas gender showed no significant association. CONCLUSION: Isolated fetal abdominal cysts have a good prognosis with a high rate of spontaneous regression (67.6%) and a low rate of surgical intervention (16.2%). However, especially first trimester cysts carry a significant risk of persistent lesions necessitating surgical intervention for which follow-up is recommended, even when prenatal regression is suspected.