Modeling fetal cavum septum pellucidi width by quantile regression at 18-34 weeks of gestation: A prospective cross-sectional study

Objective: Develop charts for cavum septum pellucidi (CSP) following a standardized methodology and using quantile regression. The secondary objective was to assess the influence of fetal gender on the generated reference curves. Methods: In a cross-sectional prospective study 453 low-risk singleton pregnancies were evaluated at a gestational age interval between 18 and 34 weeks. The width of CSP were measured on ultrasound images using a standardized technique and their changes were evaluated by quantile regression as a function of gestational age (GA) interval or head circumference (HC). Differences between sex were evaluated. Results: The measurement of CSP significantly increased with gestation and HC. Linear models better described the changes of CSP with GA and HC. The fits of CSP width with GA and HC were not significantly different. Male fetuses showed significantly higher CSP width when compared to female fetuses (u = 2.973; p = 0.005). Conclusions: We generated prospective nomograms of fetal CSP development using quantile regression and following a strict standardized methodology. These new charts may be useful to better identify abnormal cases at higher risk of associated anomalies. Further our findings underline the potential effect of gender in developing fetal brain.