{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,7,17]],"date-time":"2026-07-17T06:07:26Z","timestamp":1784268446651,"version":"3.55.0"},"reference-count":23,"publisher":"MDPI AG","issue":"7","license":[{"start":{"date-parts":[[2026,7,17]],"date-time":"2026-07-17T00:00:00Z","timestamp":1784246400000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["Medicina"],"abstract":"<jats:p>Background and Objectives: Posterior fossa anomalies (PFAs) represent a heterogeneous group of congenital malformations involving the cerebellum and adjacent structures. Prenatal counseling remains challenging because neurodevelopmental outcomes vary substantially according to the specific anomaly. This study aimed to evaluate ultrasonographic and fetal magnetic resonance imaging (MRI) characteristics, associated anomalies, genetic test results, and perinatal and neurodevelopmental outcomes of prenatally diagnosed PFAs in a tertiary care population. Materials and Methods: This retrospective study included 115 fetuses diagnosed with PFAs between 2020 and 2024. PFAs were categorized into \u201csimple\u201d (mega cisterna magna, Blake\u2019s pouch cyst [BPC], and arachnoid cyst) and \u201ccomplex\u201d (Dandy\u2013Walker malformation [DWM], vermian agenesis\/hypoplasia, cerebellar hypoplasia, Joubert syndrome, Walker\u2013Warburg syndrome, and pontocerebellar hypoplasia). Maternal characteristics, associated cerebral and extracerebral anomalies, fetal MRI findings, genetic test results, and pregnancy and postnatal outcomes were analyzed. Results: Among 115 cases, 44.3% were isolated, and 55.6% were non-isolated. Ventriculomegaly was detected in 35.6% of cases and was significantly more frequent in the complex group (47.9% vs. 14.2%). Fetal MRI was performed in 35.6% (n = 41) of cases and demonstrated a 24.3% discrepancy rate with ultrasound, mainly in differentiating DWM from BPC. Genetic testing was performed in 66.9% of cases, revealing chromosomal abnormalities in 15.6% of the total cohort. Complex anomalies, including cerebellar hypoplasia and vermian agenesis\/hypoplasia, were more frequently associated with pathogenic copy-number variants and monogenic disorders. The simple group (n = 42) had favorable outcomes, with an 89.2% survival rate and neurodevelopmental delay in 15.2% of survivors. In contrast, the complex group (n = 73) had significantly poorer outcomes (p &lt; 0.001), with a 38.1% survival rate, 42.5% rate of pregnancy termination, and neurodevelopmental delay in 56.3% of survivors. Conclusions: This study highlights the persistent diagnostic challenges associated with PFAs and underscores the importance of multimodal imaging and comprehensive genetic evaluation. The proposed simple\u2013complex classification provides a clinically meaningful framework for prognostication and parental counseling. Future research should prioritize prospective multicenter studies with higher rates of comprehensive genetic testing coupled with standardized long-term neurodevelopmental follow-up to refine the understanding of the natural history and prognostic trajectory of these complex brain malformations.<\/jats:p>","DOI":"10.3390\/medicina62071375","type":"journal-article","created":{"date-parts":[[2026,7,17]],"date-time":"2026-07-17T05:32:17Z","timestamp":1784266337000},"page":"1375","update-policy":"https:\/\/doi.org\/10.3390\/mdpi_crossmark_policy","source":"Crossref","is-referenced-by-count":0,"title":["Prenatal Diagnosis and Perinatal Outcomes of Posterior Fossa Anomalies in a Tertiary Referral Center: A Five-Year Experience"],"prefix":"10.3390","volume":"62","author":[{"ORCID":"https:\/\/orcid.org\/0000-0002-5937-0220","authenticated-orcid":false,"given":"Verda","family":"Alpay","sequence":"first","affiliation":[{"name":"Department of Obstetrics and Gynecology, Division of Perinatology, Ba\u015fak\u015fehir \u00c7am and Sakura City Hospital, 34480 Istanbul, Turkey"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"F\u0131rat","family":"Ersan","sequence":"additional","affiliation":[{"name":"Department of Obstetrics and Gynecology, Division of Perinatology, Ba\u015fak\u015fehir \u00c7am and Sakura City Hospital, 34480 Istanbul, Turkey"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-3831-3745","authenticated-orcid":false,"given":"Bar\u0131\u015f","family":"Boza","sequence":"additional","affiliation":[{"name":"Department of Obstetrics and Gynecology, Division of Perinatology, Ba\u015fak\u015fehir \u00c7am and Sakura City Hospital, 34480 Istanbul, Turkey"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Melike","family":"Makul","sequence":"additional","affiliation":[{"name":"Department of Obstetrics and Gynecology, Division of Perinatology, Ba\u015fak\u015fehir \u00c7am and Sakura City Hospital, 34480 Istanbul, Turkey"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-1418-634X","authenticated-orcid":false,"given":"\u0130brahim","family":"Polat","sequence":"additional","affiliation":[{"name":"Department of Obstetrics and Gynecology, Division of Perinatology, Ba\u015fak\u015fehir \u00c7am and Sakura City Hospital, 34480 Istanbul, Turkey"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-5879-6385","authenticated-orcid":false,"given":"Aydeniz Ayd\u0131n","family":"G\u00fcm\u00fc\u015f","sequence":"additional","affiliation":[{"name":"Department of Medical Genetics, Ba\u015fak\u015fehir \u00c7am and Sakura City Hospital, 34480 Istanbul, Turkey"}],"role":[{"vocabulary":"crossref","role":"author"}]}],"member":"1968","published-online":{"date-parts":[[2026,7,17]]},"reference":[{"key":"ref_1","doi-asserted-by":"crossref","first-page":"247","DOI":"10.1159\/000484316","article-title":"Patterns of Detection of Fetal Posterior Fossa Anomalies: Analysis of 81 Cases in the Second Half of Gestation","volume":"44","author":"Friszer","year":"2018","journal-title":"Fetal Diagn. 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