Coronal Subarachnoid‐Space Measurements in Fetuses with Growth Restriction and Appropriate‐for‐Gestational‐Age Controls
Esra Selvi, Hale Özer Çaltek, Hamdullah Pekkolay, Barış BozaObjectives
To compare coronal sinocortical width (SCW) and craniocortical width (CCW) between fetuses with fetal growth restriction (FGR) and appropriate‐for‐gestational‐age (AGA) fetuses and to assess interobserver agreement.
Methods
This prospective cross‐sectional comparative study included 281 singleton pregnancies examined at 28 + 0 to 36 + 6 weeks: 145 with FGR and 136 AGA controls. Two observers independently measured SCW and CCW transabdominally in a standardized coronal plane. Primary analyses used gestational‐age‐adjusted linear regression with Holm correction. Head‐circumference sensitivity analyses and interobserver agreement assessments were performed.
Results
Mean SCW was 2.26 ± 0.86 mm in the FGR group and 2.68 ± 0.96 mm in the AGA group; the adjusted difference was −0.426 mm (95% CI, −0.642 to −0.210; Holm‐adjusted p < .001). For CCW, the FGR‐by‐gestational‐age‐window interaction was significant ( p = .006), with a larger adjusted difference at 28 + 0 to 30 + 6 weeks (−0.707 mm; Holm‐adjusted p = .007) and no significant differences in the later windows after Holm correction. Single‐measure absolute‐agreement ICCs were 0.869 for SCW (95% CI, 0.726–0.967) and 0.863 for CCW (95% CI, 0.813–0.904); corresponding average‐measures ICCs were 0.930 (95% CI, 0.841–0.983) and 0.926 (95% CI, 0.897–0.949), respectively.
Conclusions
Coronal SCW was smaller, on average, in fetuses with FGR, whereas CCW differences varied across gestational‐age windows. After head‐circumference adjustment, the SCW difference persisted, whereas the CCW estimate was attenuated and no longer statistically significant. The Bland–Altman limits of agreement exceeded the average between‐group differences, limiting individual‐level interpretation. Further longitudinal studies are needed to determine clinical relevance.