how accurat are due dates and conception dates done by ultrasound?

[EriBoe]

Im just curious to know. My LMP was August 2nd 2012. But it doesnt match up at all with the ultrasound due date and conception date. Please help.

[EriBoe]

sorry for my repeated questions... my phone is dumb sometimes.
and to mrsmount1217 i am feeling pretty good. i have no pregnancy symptons but i feel her kick all the time. I am having a girl and her name is Chyler. how are you feeling and what are you having?

[beauty12]

due date is usually given  after U/S measurements.. and they are pretty accurate however baby can come mostly between 37-40wks..

[melsbells5]

I'm due may 12! How are you feeling?are you having a boy or girl? :)

[RockRose]

If you just now got the ultrasound,  that's not accurate.  They are incredibly accurate in the first 8 weeks if the pregnancy is healthy.  So if you had a US at 6 weeks and then got this far with a healthy pregnancy,  you could take to the bank the due date you were originally given.

At 22 weeks,  they aren't that accurate.  There is an enormous range of sizes for healthy full term babies - from 6.5 pounds to 9.5.  That allows for a LOT of size variation!

If your LMP was Aug. 2,  there is a chance that you did conceive mid-August and this US was wrong.

[MrsMount1217]

If your first day of your last period was august 2nd, and you have a period 5-7 days, then no, you probably didn't conceive in the first 2 weeks of august considering aug 2-9 you were on your period. Why is this so important to you to know, I mean not to sound rude, but how come you're not content with your ultrasound & what your doc says?

[EriBoe]

Is there a chance o concived in the first 2 weeks of august?

[EriBoe]

Is there anyway i could have concived the first 2 weeks of august?

[AnnieBrooke]

Are your cycles irregular?  A 23-day gap between your actual first day of last period and when the ultrasound measurement suggests there should have been a period is a little unusual.  My guess (because an ultrasound actually looks at the baby and makes measurements) is that you had something funny about your period or cycle in August, such as an ovarian cyst, and it kind of made things unusual.  Was the August 2 period kind of weird?  Did you have any hint of bleeding three weeks later when the supposed August 25 or 26 imputed first day of a last period would have been?

In any case, I would trust the ultrasound, especially if you have had more than one.

[MrsMount1217]

Probably not, not if the first day of your last period was aug 2nd.

[MamacitaTP]

Not really..

[EriBoe]

Is there anyway i could have concived the first 2 weeks of august?

[EriBoe]

Is there anyway i could have concived the first 2 weeks of august?

[MrsMount1217]

Yes bc the ultrasound is the most accurate, that's what my obgyn told me

[Cpbt13]

Yes the ultrasound date is most accurate

[EriBoe]

So would you go with ultrasound date?

[MrsMount1217]

*you could have conceived in august.

[MrsMount1217]

My lmp was aug 5, date of conception aug 19, I'm 25w4d due may 13, so yeah u conceived in august

[EriBoe]

My LMP was August 2nd 2012which would put me at 26 weeks today and a due date of May 9th 2013. And by ultrasound im 22 weeks and 5 days today which would give me a due date of June 1st. And a LMP of August 25th 2012. Which the docotrs gave me. Is there any way i concived in August?

[AnnieBrooke]

ps -- The later in pregnancy you have an ultrasound, the less accurate it can be for dating purposes, because babies grow at different rates.  Use your earliest ultrasound for purposes of trying to pinpoint conception.

[AnnieBrooke]

OK, just to be sure, you do know that your conception date will not be the first day of your lmp, right?  It would generally be a couple of weeks later, though it could be different than that if a woman has irregular cycles.  

Anyway, go with what the ultrasound says.  The ultrasound sees and measures the actual embryo.  How far different are the due date based on your ultrasound and the due date based on the first day of your cycle?

[MamacitaTP]

The ultrasound is very accurate.