The use of the abdominal circumference as a means of assessing M-mode ventricular dimensions during the second and third trimesters of pregnancy in the normal human fetus.

Eighty-two normal fetuses were scanned from 18 to 41 weeks of gestation. The following M-mode measurements were correlated with the abdominal circumference: diastolic biventricular outer (r = 0.951) and inner (r = 0.948) dimensions; diastolic right (r = 0.942) and left (r = 0.925) internal dimensions; tricuspid (r = 0.916) and mitral (r = 0.900) valve opening excursions; and right (r = 0.774), left (r = 0.731), and interventricular septal (r =...