First-trimester volumetry includes measurement of the volume of the placenta (PV), embryo (EV), fetus (FV), gestational sac and yolk sac. PV, EV/FV ratio and gestational sac volume are correlated ...

The next step on ultrasound is usually the appearance of the yolk sac within the gestational sac. The yolk sac functions as nourishment for the developing embryo and can usually be seen by five ...

examined the relationship between serum β-hCG and the results of 256 pelvic ultrasounds performed by 36 Emergency Physicians (EPs) credentialed in early OB ultrasound ... of yolk sac or fetus ...