Perinatal and Short-Term Neonatal Outcomes of Posterior Fossa Anomalies

Abstract

Objective: To describe the perinatal and neonatal outcomes for fetuses with posterior fossa (PF) anomalies - mega-cisterna magna (MCM), persistent Blake's pouch (PBP) or the Dandy-Walker continuum (DWC) - using a new classification. Methods: 46 cases with PF anomaly diagnosed on ultrasound (US) between 16 and 28 weeks' gestation were included. The images were reviewed and classified as one of the following: MCM, PBP or DWC. Outcomes were obtained from patient records. Results: 30 cases with DWC, 6 with MCM, and 10 with PBP were identified. Associated anomalies were present in all groups, but more frequent in DWC. Agenesis of the corpus callosum and ventriculomegaly were more common in DWC than in MCM or PBP. Only fetuses with DWC were found to have chromosomal abnormalities. Perinatal outcomes differed significantly, with terminations of pregnancy more frequent in DWC. In the immediate postnatal period, infants with DWC had worse outcomes than those with MCM and PBP. Across all groups, those with associated anomalies had worse outcomes than those with an isolated PF anomaly. Conclusion: Infants antenatally diagnosed with DWC had worse perinatal and short-term neonatal outcomes than those with MCM or PBP. Those with associated anomalies had uniformly poorer outcomes than those with isolated anomalies.

Systematic review and meta‐analysis of isolated posterior fossa malformations on prenatal ultrasound imaging (part 1): nomenclature, diagnostic accuracy and associated anomalies

“…A total of 1640 articles were identified, of which 97 full‐text articles were assessed for their eligibility for inclusion (Appendix S2). A total of 22 studies were included in the systematic review (Figure ). These 22 studies included 531 fetuses with posterior fossa anomalies; of these, 226 (42.6%) did not show any additional structural anomaly at the scan and represent the population of this systematic review.…”

“…The prevalence of additional CNS abnormalities missed at ultrasound and detected only on prenatal MRI was 13.7% (95% CI, 0.2-42.6%; Table 3), while the rates of additional CNS and extra-CNS anomalies 20 Tonni (2014) 21 Ghali (2014) 22 Zhao (2013) 23 Vatansever (2013) 24 Guibaud (2012) 25 Gandolfi Colleoni (2012) 26 Paladini (2012) 27 Patek (2012) 28 Bertucci (2011) 29 Egle (2011) 30 Ozkan (2011) 31 Rizzo (2011) 32 Dror (2009) 33 Kontopoulos (2008) 34 Forzano (2007) 35 Long (2006) 36 Zalel (2006) 37 Has (2004) 38 Leitner (2004) 39 Ecker (2000) 40 Kölble (2000) 41 A study can be awarded a maximum of one star for each numbered item within the selection and outcome categories. A maximum of two stars can be given for comparability.…”

Accuracy of diagnosis and counseling of fetal brain anomalies prior to 24 weeks of gestational age

“…However, despite the challenges of early gestation and early stage brain development overall diagnostic accuracy rate in this study was 92% prior to 24 weeks' GA. Counseling on postnatal prognosis was accurate in 98% prior to 24 weeks' GA, even though the neurodevelopmental outcome can vary greatly depending on the severity of the anomalies, the presence of associated anomalies or a genetic diagnosis [23,[25][26][27].…”

Chromosomal aneuploidies and copy number variations in posterior fossa abnormalities diagnosed by prenatal ultrasonography

“…Each PFA has a distinct embryological basis . Given the limited knowledge of the genetic aetiologies of PFAs, it is highly challenging to perform genetic counselling when a fetus is diagnosed with a PFA, especially because the outcomes of such conditions vary considerably depending on the type of anomaly …”