“Is my baby all right?” Commentary on “The importance of first trimester screening of cranial posterior fossa in predicting posterior fossa malformations which may be identified in the following weeks of gestation” by Ozdemir et al. David N Jackson, MD

“Is my baby all right”? This is the foremost question of parents following perinatal imaging. It encompasses discussing abnormalities and the confirmation of reassuring anatomy. In the reviewed article by Ozdemir et al., the value of targeted measurements within the fetal posterior fossa at 11–14 weeks was studied at Zeynep Kamil Women and Children's Diseases Training and Research Hospital in Istanbul. A prospective control group of 328 fetuses with normal postnatal outcome were compared to 22 fetuses with subsequent posterior fossa pathology. They performed first trimester central nervous system (CNS) imaging as outlined by the Fetal Medicine Foundation for scans between 11 and 14 weeks of gestation. They then added measurements of the intracranial translucency (IT), brainstem (BS), and calculations of the brainstem (BS) to brainstem-to-occipital bone (BSOB) ratio. The authors found an impressive negative predictive value of 100% when IT value, BSOB value, and BS/BSOB ratio were determined at cut off values of 2.7, 5.1, and 0.3 respectively. If this holds true in future studies, we can one day counsel first trimester patients that posterior fossa pathology such as Dandy–Walker malformation (DWM), vermian hypoplasia, Blake's pouch cyst (BPC), and mega cisterna magna will be absent in the neonate. What is the practical use of this information? When IT, BSOB, and BS/BSOB ratio are assessed, they not only identify abnormalities, but seem to accurately predict future normal development of the fetal posterior fossa. Since the frequency of abnormal posterior fossa syndromes is rare, the majority of our patients will benefit from hearing early confirmatory normal results. 2 | BACKGROUND