Sonographic evaluation of the normal developmental anatomy of the fetal cerebral ventricles: II. The atria.

A prospective ultrasound study was conducted on 171 normal pregnancies ranging in gestational age from 15 weeks to term to evaluate the developmental anatomy of the atria of the lateral ventricles. The atrial width showed no significant modifications throughout gestation, remaining fairly constant. Significant linear relationships were found between the cerebroatrial distance and gestational age (R2 = 0.88; P less than .0001) and between the cerebroatrial distance and the biparietal diameter (R2 = 0.936; P less than .0001), with a first- and second-order regression equation being the best fit, respectively. From these data, growth of the atria was characterized both biologically and mathematically, providing a comprehensive evaluation of the atrioventricular system throughout pregnancy. Such data offer the potential for early prenatal diagnosis of various types of developmental abnormalities of the fetal ventricular system.