Dating and viability
At 5 weeks gestation only a gestation sack will be seen.
After this a yolk sac will be visible, then a small fetus.
This scan is useful for women who are experiencing pain or bleeding in the pregnancy and those who have had previous miscarriages or ectopic pregnancies.
The ultrasound appearance will depend on the gestational age of the pregnancy.
I recently started coding for an OB office that routinely schedules patients for a viablility/dating ultrasound and visit with the physician before starting the "official" prenatal record.The baby's length is measured from head to bottom (Crown Rump Length) up to 14 weeks.Later on the measurements of the head, Bi-Parietal Diameter, (BPD), are used to determine the Expected Date of Delivery.In this case a follow up scan after an interval when normal growth can be expected to now show these things will be recommended.As part of the scan report the due date for the baby based on the ultrasound size in the first 12 weeks will be provided to your doctor.