Ultrasound measurement of the fetal cavum septi pellucidi

Objectives To establish normative data for the width of the fetal cavum sep ti pellucidi at various gestational ages. Subjects and methods A total of 608 consecutive fetuses between 19 and 42 g estational weeks were included in this prospective study. The largest width of the cavum septi pellucidi was measured by two-dimensional ultrasound. P iecewise regression analysis was used to study the relationships between th e width of the fetal cavum septi pellucidi, gestational age and biparietal diameter. Results The fetal cavum septi pellucidi width increased gradually between 1 9 and 27 weeks of gestation and then plateaued between 28 weeks and term. R egression analysis revealed significant associations between cavum septi pe llucidi width and gestational age, and cavum septi pellucidi width and bipa rietal diameter. Conclusions The present study provides normative data for fetal cavum septi pellucidi width and useful information about the development of the midlin e brain structure in the fetus.