Abstract:Objective To summarize the ultrasonographic features of fetal intra-abdominal cystic mass in order to provide a basis for timely clinical intervention. Methods The ultrasound findings and postoperative pathology of 48 cases of fetal intra-abdominal cystic masses discovered by prenatal ultrasound examination from January 2014 to January 2016 were retrospectinely analyzed and followed up to birth,and the source and nature of the cysts were partially confirmed by surgery. Results Prenatal ultrasound combined with postnatal ultrasound and part of the results of surgery showed that among the 48 cases of fetal intra-abdominal cystic mass,adrenal region was found in 5 cases (10.4%);lower abdominal cystic mass was found in 19 cases,of which 15 cases (31.2%) were ovarian cysts and underwent surgical treatment,and ovarian cysts with torsion was found in 5 cases after birth;9 cases (18.7%) of renal region were mostly congenital polycystic renal dysplasia;and there were 15 cases of other parts (upper abdomen,bladder,etc). Conclusions Ultrasound can accurately indicate the nature of cystic mass in the intra-abdominal cavity of some fetuses.Adrenal cysts,congenital polycystic renal dysplasia and duodenal obstruction can be given more clear hints,while congenital common bile duct cysts can be given tendencies, the sex of the fetus should be observed for ovarian cysts;it is difficult to make a definite diagnosis of intestinal duplication,mesenteric cyst and exogenice hepatic cyst.