Crown/rump length and gestational age are closely compared with each other until around the end of the first trimester.
The ideal time for a sonographer to assess the gestational age in the first trimester is between 7-10 weeks of pregnancy.
It may also be offered after 11 or 12 weeks if a trans-abdominal scan doesn’t give a clear enough picture.
From 11 or 12 weeks, including at the routine booking-in scan, it is more common to have a trans-abdominal scan.
At around seven weeks of pregnancy, it’s reasonably common for women to have their first ultrasound.
This can be for many reasons but the most common is to confirm pregnancy and to check that the embryo is viable and “everything’s ok”.
We will always try to scan trans-abdominally first but if we need to do an internal scan then this will not be harmful in any way to the baby and would be discussed prior to having the scan.
They agreed to send me in for HCG testing this week as they put it for 'more scientific proof'. We have two beautiful children already and this third was a surprise gift to us this summer.
I had my 2nd HCG test today and have not heard the results. Miscarriage was never on my mind because we got pregnant under somewhat miraculous circumstances so the news took my legs out from under me.
This is the period of time which provides the most accurate assessment.
Generally, ultrasounds which are performed in the first trimester are within 3-5 days of being accurate in terms of assessing gestational age.