12 week dating scan pregnancy
Otherwise a scan is generally booked in the first trimester to confirm pregnancy, exclude ectopic or molar pregnancies, confirm cardiac pulsation and measure the crown to rump length for dating.
The 12 week scan is a routine ultrasound examination carried out at 10 to 14 weeks of gestation.
The test is performed between 11 weeks and 13 weeks 6 days into your pregnancy.
The test cannot be performed outside this time frame as certain features that need to be seen on the scan are not present.
The CRL (see image above between the two white marked 1) is highly reproducible and is the single most accurate measure of gestational age.
The fluid collection is however increased in many fetuses with Down's syndrome and many other chromosomal abnormalities.So dont worry if they have told you that you are a few weeks behind what you thought! xx If your due date is 9th July you would have conceived around 16th October or there abouts, if you conceived September 10th this would give you a due date of around June 3rd/4th. Scans are pretty accurate, I can't see them being that far out.Obviously it depends on when ovulation occured but if they have given you 9th July that's what I would go with.This is a routine ultrasound examination done at 10 to 14 weeks of gestation.During the examination, the fetus is seen by abdominal ultrasound.