Analysis of the prenatal ultrasound diagnostic value and prognostic factors of fetal mediastinal cysts

Background: A prenatal fetal mediastinal cyst is a benign disease. However, if a cyst enlargement grows, it may compress the adjacent organs and affect the fetal cardiopulmonary function. This study aimed to compare and analyze the prenatal ultrasound characteristics of different mediastinal cysts, and to evaluate the pregnancy outcome of the fetus and the factors affecting the prognostic of the fetus. To compare and analyze the prenatal ultrasound characteristics of different types of mediastinal cysts, and to evaluate the fetal pregnancy outcome and the influencing factors of fetal prognosis. Methods: A retrospective analysis of patients with prenatal diagnoses of mediastinal cysts was conducted to evaluate the ultrasound characteristics and to monitor the pregnancy outcomes to identify prognostic influences and provide a reliable basis for patient prognosis. Results: In total, 30 patients were diagnosed with mediastinal cysts [including bronchogenic cysts (n=12), esophageal cysts (n=9), pericardial cysts (n=5), and thymic cysts (n=4)] on prenatal ultrasonography. The diagnostic accuracy rate was 93.33%; two cases of esophageal cysts were misdiagnosed as bronchial cysts. In total, 4 (44.44%) of 9 esophageal cysts and 4 thymic cysts were located in the anterior mediastinum, 10 (83.33%) of 12 bronchogenic cysts and 5 pericardial cysts were located in the middle mediastinum, and 2 (16.67%) of 12 bronchogenic cysts and 5 (55.56%) of 9 esophageal cysts were located in the posterior mediastinum. There were significant differences in the distribution of the cyst location, morphology, and cyst wall thickness (P<0.05). After delivery, 17 patients had clinical symptoms. There was a significant difference in the clinical symptoms between patients with a maximum diameter of postpartum cysts <5 and >= 5 cm (P<0.05), and children with a low gestational age and birth weight were more likely to have clinical symptoms. Conclusions: The prenatal ultrasound features of fetal mediastinal cysts were similar. However, the ultrasound characteristics related to the cyst location, morphology, and cyst wall thickness were helpful in providing an accurate diagnosis. In addition, the postpartum cyst size, location, adjacent relationship with the surrounding tissues, volume, gestational age, and weight were related to patient prognosis.