The diagnosis of anembryonia (empty fertilized egg) is assumed if a yolk sac is not detected in a fertilized egg measuring 20 mm. Or if the fertilized egg with a diameter of more than 25 mm with a yolk sac does not contain an embryo. And also when the yolk sac size is 10 mm or more. In any case, if anembryonia is suspected, all data obtained should be interpreted in favor of pregnancy, and the study should be repeated after 7 days.
The diagnosis of a non-developing pregnancy should not be made if, on ultrasound, the ovum is less than 20 mm in size. When the embryo is 5 mm or more in length, in most cases the heartbeat should be clearly detectable. If the embryo is less than 5 mm, the ultrasound should be repeated after a week. If, upon repeated examination a week later, at CTE = 5-6 mm, cardiac activity is not detected, the pregnancy is not viable. The diagnosis of a non-developing pregnancy can be confirmed by a discrepancy between the beta-hCG level and echographic data.
It should be noted that the normal rate of pregnancy termination in the population is 15-20% of all clinically diagnosed pregnancies. However, in reality, if we count all “chemically” diagnosed pregnancies, determined by the level of beta-hCG before the expected next period, the miscarriage rate can reach up to 60%.