Ultrasound confusion

[earlytwentiesmama]

Hi Everyone,

I'm just wondering I know doctors take your gestational age as from your LMP but is that the same in ultrasound as well?

So if you measure at 10 weeks does that mean you actually conceived about 8 weeks ago? I find it all so confusing!x

Thankyou x

Yes that’s correct. You have a ‘free’ 2 weeks

Scan Date 12w
Conceived 10w ago

Yes, round about 8wk from conception if baby measures 10wk.
Your "estimated" due date goes off baby size as they are roughly the same sizes around the dating scan. It can still be slightly out as babys have growth spurts rather than steady growth so not completely accurate for when conception could have been.

Yes exactly that. It's all a bit imprecise but they will rely on the ultrasound date for the rest of your pregnancy to plan your care. If it's a few days out from LMP date/when you "know" you conceived don't worry - the scan is considered to be the most reliable estimate but it is still an estimate. They use it to work out when you should have scans, vaccines, appointments, induction etc. Only 5% or so of babies are actually born on their calculated due date but most are born within the 2 weeks either side.

Thankyou everyone, trying to deal with a partner who works away and he couldn't understand how I would be 10 weeks when we could have only conceived 8 weeks ago. Think he was thinking other thoughts... but I hope this helps him to understand! Thankyou so much x

Typical, they always struggle with the dating at 1st.
My husband works away too and likes to joke about dates, he's lucky I like him enough not to kill him sometimes lol.