Open Spina Bifida: The Role of Ultrasound Markers in the First Trimester and Morphopathology Correlation

Objectives-To evaluate ultrasound markers during a first-trimester (FT) routine ultrasound examination for an early detection of open spina bifida (OSB) and to correlate the sonographic findings with the morpho-histological ones.

This retrospective research was performed using data from foetuses that underwent FT anatomy scans (FTAS) with a gestational age between 11 weeks and 13 weeks and 6 days in the Prenatal Diagnostic Unit of the Clinical Emergency County Hospital Craiova from October 2022 until September 2023.

The study included 648 FT singleton pregnancies and 5 OSB cases were detected. In the OSB group, we found abnormal aspects of the fourth ventricle, also named intracranial translucency (IT) in 4 out of 5 cases of OSB (80%), a brain stem anteroposterior diameter, and brain stem to occipital bone ratio abnormal in all 5 cases (greater than 1) (100%), the crash sign was present in 80% (4 out of 5 cases) and the spinal defect was visualized in 4 out of 5 patients (80%). Medical termination of pregnancy (MTOP) was the preferred option in all cases of OSB. This allowed us to include an extended histological study to confirm the ultrasound diagnosis.

A combined detailed FTAS that includes both cranial ultrasound markers of the posterior fossa and also a good visualization of the foetal spine offers an early optimal detection rate of spine abnormalities.