Method and system for determining a volume of a placenta in utero. The placenta in utero may be modeled as having a convex-concave shape (e.g., like that of a portion of a spherical shell). Volume of the placenta may be determined based on the width (or height) and thickness of the placenta, or based on width, height and thickness of the placenta. Placenta size characteristics may be measured using imaging techniques, such as ultrasound. In one aspect of the invention, a volume of a placenta in utero may be compared to the volume of other placentas for similar gestational age, and a determination regarding whether the placenta volume poses a risk to fetal health may be made.
