How accurate are ultrasounds at dating pregnancy Web 123 camr sxe vido
The limbs and the yolk sac, though obviously important, are not the primary means of measuring growth.
This is why an early pregnancy dating scan, rather than one done in the later stages of pregnancy, is considered more accurate when assessing the expected date of delivery.
With maturity, the size of the baby correlates less to its age than in the early weeks.
In some respects the seven week ultrasound can be quite accurate because the embryo is developing very quickly.
They are also not as mobile and active as they will be with future development.
This is because although every little embryo is unique, there are still defining characteristics of development which apply to all embryos at particular stages of early gestational development.