Diagnosis and prognosis of fetal periventricular pseudocysts

Objective To investigate the diagnosis, clinical outcomes and factors influencing the prognosis of fetal periventricular pseudocysts (PVPC). Methods A retrospective analysis was performed on the results of fetal neurosonography (NSG), cranial magnetic resonance imaging (MRI), chromosome karyotype and neonatal cranial ultrasound of 76 PVPC cases detected by prenatal ultrasound in Peking University First Hospital from May 2014 to October 2018. The accuracy of NSG and cranial MRI in PVPC diagnosis was assessed. Prognosis of PVPC and the influencing factors were evaluated. Statistical analysis was performed using Chi-square test or Fisher's exact test. Results (1) This study involved 51 cases (67.1%) of isolated PVPC and 25 cases (32.9%) of non-isolated PVPC. Among the 25 non-isolated PVPC cases, 15 were complicated by one abnormality and 10 by multiple abnormalities. There were 20 cases with intracranial abnormalities, two with extracranial abnormalities, and three with both intracranial and extracranial abnormalities. (2) Eight out of the 76 pregnancies (10.5%) were terminated and among them, two were isolated PVPC cases, five complicated by determined abnormalities (one case of PVPC complicated with pachygyria and bilateral mild fetal ventriculomegaly, one case of PVPC complicated with pachygyria or agyria and agenesis of corpus callosum, one case of PVPC complicated with arachnoid cyst and vermis dysplasia, one case of PVPC complicated with cortical dysplasia, one case of PVPC complicated with intestinal dilatation) and one by abnormalities of undertermined prognosis (PVPC combined with mild fetal ventriculomegaly and polyhydramnios). A total of 61 neonates (80.3%, 61/76) were born alive and followed up. Seven cases (9.2%, 7/76) were lost to follow-up. (3) As of February 2019, among the 61 followed-up infants, 44 with isolated PVPC and 15 with unclear abnormalities developed well. The other two with determined intracranial abnormalities were diagnosed as having cystic lesions in the brain parenchyma. One of them died of respiratory failure two days after birth and the other suffered from chromosomal disease (13.23 Mb deletion in region q24.3q31.2 of chromosome 2) with mental retardation and delayed growth and development. (4) A total of 44 (57.9%, 44/76) neonates received cranial ultrasound after birth and confirmed the diagnosis of PVPC, among which 11 (25.0%, 11/44) were missed or misdiagnosed in prenatal MRI. Conclusions PVPC may have many comorbidities, particularly intracranial abnormalities, which are closely related to the prognosis. A thorough prenatal ultrasound examination is necessary for fetal PVPC, especially NSG. Isolated PVPC usually has a good outcome. However, PVPC complicated by cystic lesions in the brain parenchyma may be associated with chromosomal abnormalities, hence fetal chromosome examination is required. Key words: Lateral ventricles; Central nervous system cysts; Ultrasonography, prenatal; Prognosis