To evaluate alterations of periventricular pseudocysts (PVPC) on MRI before and after birth, and to assess the prognosis.

We retrospectively analyzed the data of 67 cases that were diagnosed with PVPC on prenatal MRI, of which 24 cases were lost to follow-up, 2 died after birth. A total of 41 surviving fetuses were included in this prognosis study. The gestational ages in this group were between 23 and 39 weeks, with an average of (33±3) weeks.All the subjects underwent brain MRI examinations and Gesell Developmental Scale (GDS) testing between 0-3 years of age. According to the location of cysts and with or without other intracranial and extracranial malformations (dilated ventricles orcerebella medulla, hypoxic-ischemic encephalopathy, TORCH virus infection, corporal hypoplasia, chromosomal malformations and nodular sclerosis) , the patients were divided into four groups: isolated connatal cysts, connatal cysts with additional findings,isolated subependymal pseudocysts, and subependymal pseudocysts with additional findings.The MR images were independently reviewed by two radiologists blinded to the clinical information. Intraclass correlation efficient (ICC) was used to analyze the consistency between the two reviewers.Chi-square test was used to compare the location of cysts (single/bilateral), the number of cyst cavities (single/multi-chamber), and other abnormalities in the connatal cyst group and subependymal cyst group. The mean anteroposterior diameter and mean height of cysts between the connatal cyst group and subependymal cyst group were compared by independent sample t-test.The ANOVA test was used to compare the differences in GDS outcomes among the groups. Multiple comparisons were conducted using the LSD test.

Inter-observer agreements between the two radiologists were good for the collected data (all ICC>0.75). Eleven isolated connatal cysts and 7 connatal cysts with additional findings became smaller or disappeared, and all had good prognosis. Of the 14 isolated subependymal cysts, 12 became smaller or disappeared, 2 had no change in size, and 13 had good prognosis. The subependymal cysts with additional findings group included 9 cases: 6 became smaller or disappeared, only 3 showed no apparent changes, and 7 had an abnormal outcome. Subependymal cysts with additional findings were significantly reduced and patients demonstrated significant differences compared with the those with isolated subependymal cysts in the development quotients (DQ) of adaptability, large movements, fine movements, personal social interaction, and language DQ (P all<0.05). DQ between patients with isolated connatal cysts and isolated subependymal cysts was comparable (P all>0.05). When associated with additional findings, connatal cysts and subependymal cysts could induce significant different DQ outcome (P all<0.05).

Isolated PVPC usually become smaller or disappeared and have a benign presentation after birth, whereas patients with subependymal cysts with additional findings usually have a poor prognosis. Connatal cysts usually have a good prognosis.

Fetus; Ventricular; Cysts; Magnetic resonance imaging; Prognosis