The Predictive Value of Dry Brain Sign for Open Spina Bifida at First Trimester Anomaly Scan: A Case-Control study.

RATIONALE AND

OBJECTIVES

Spina bifida is a common neural tube defect resulting from incomplete closure of the spinal column, with early detection crucial for prenatal management. This work aimed to assess the diagnostic utility of the dry brain sign in first-trimester sonographic screening for open spina bifida (OSB).

MATERIALS AND

METHODS

This prospective case-control study included 50 pregnant women (aged 18-40 years) who underwent first-trimester ultrasound screening for singleton pregnancies. Participants were divided into two equal groups: 25 controls with normal ultrasound findings and 25 cases exhibiting a positive "dry brain sign," defined by enlarged choroid plexuses without surrounding cerebrospinal fluid. Second and third-trimester ultrasound findings were used to confirm OSB diagnoses.

RESULTS

The case group exhibited significantly higher mean choroid plexus (CP) length, CP to occipitofrontal diameter (CP/OFD), and CP to biparietal diameter (CP/BPD) ratio (p= 0.001). BPD and OFD were significantly lower in the case group compared with the controls (p= 0.001). CP/BPD and CP/OFD demonstrated the highest diagnostic accuracy (100%) with optimal sensitivity and specificity. CP/BPD (cutoff ≥0.65, p < 0.001) and mean BPD (cutoff ≤20.5 mm, p < 0.001) were reliable markers for OSB.

CONCLUSION

Dry brain sign could be used as sonographic markers for early screening in the first trimester for OSB by using mean CP/BPD ratio and mean CP/OFD ratios.