Posterior Fossa Anomalies: A Detailed Review of Prenatal Findings and Management from a tertiary care centre
In brief
Two thirds of prenatally diagnosed posterior fossa anomalies end in termination
In a single-center review of 35 fetuses with posterior fossa anomalies, 65% of pregnancies were terminated, especially after 24 weeks. Genetic testing identified pathogenic variants in only about 6% of cases, and among the nine live births, most infants showed normal development at six months, though one had delayed milestones. The findings highlight the need for precise imaging, limited genetic yield, and careful counseling.
- Journal
- Fetal diagnosis and therapy (Q2)
- Published
- 31 July 2026
- Study design
- Cohort / observational study
- Evidence level
- Level 4, Very Low (CEBM 4)
- Authors
- Tanisha Gupta, K Aparna Sharma, Vatsla Dadhwal, Anubhuti Rana, Neerja Gupta, Madhulika Kabra, et al.
- PMID
- 42536599
- DOI
- 10.1159/000553530
Why clinicians should know about it
- Picked for Embryology (top studies of the week, 2 August 2026).
Abstract
OBJECTIVE: Posterior fossa anomalies (PFAs) encompass a spectrum of central nervous system malformations affecting the cerebellum, brainstem, and surrounding cerebrospinal fluid spaces. This study evaluates the prenatal diagnosis, genetic findings, and pregnancy outcomes of PFAs in a tertiary care setting in India. METHODS: A retrospective analysis was conducted on 35 cases of PFAs diagnosed via prenatal ultrasound and fetal MRI between January 2023 and May 2024. Anomalies were classified based on standard criteria, and genetic testing (karyotypte, chromosomal microarray analysis and whole exome sequencing) was offered. Pregnancy outcomes, including termination, live birth, and neonatal survival, were documented, with short-term neurodevelopmental follow-up conducted via telephonic inquiries. RESULTS: The most common PFAs identified were Vermian Agenesis/Hypoplasia (VA/VH) and Cerebellar Hypoplasia (CH), each accounting for 25.71% of cases, followed by Dandy-Walker Malformation (20%). Isolated PFAs were observed in 37.14% of cases, while 62.85% had additional anomalies. Genetic testing was performed in 74.2% of cases, revealing variants in 5.71%. Karyotyping was performed in all tested cases and yielded normal results, while additional molecular testing with chromosomal microarray analysis (5 cases) and whole-exome sequencing (3 cases) detected clinically relevant variants in selected fetuses with posterior fossa anomalies. Among the 35 pregnancies, 65.71% opted for termination, facilitated by the Medical Termination of Pregnancy (MTP) Act, particularly for cases diagnosed beyond 24 weeks of gestation. Of the 9 live births, 2 neonates with vermian hypoplasia (5.71%) died within one month, while 6 (17.14%) had normal developmental milestones at 6 months including 6 babies with mega cisterna magna and one with an arachnoid cyst. One infant exhibited delayed milestones. CONCLUSION: PFAs present with diverse prognostic implications, necessitating detailed imaging, genetic evaluation, and individualized counseling. The MTP Amendment Act, played a crucial role in providing extended access to termination in pregnancies with severe PFAs and poor prognoses.
Abstract as published, via PubMed.
For healthcare professionals. The summary is generated by AI from the published abstract, and the evidence level is assigned automatically from the study design on the Oxford CEBM hierarchy. Neither is medical advice. Read the full paper before changing practice.