Can they get my date of conception wrong?

Question

Ive had two scans done in the 1st trimster and they both have different concpetion dates but.. theres only a differnce of 3 days between the two dates. I was wondering could they get it wrong by like 6 weeks?

Answer 1

I am no expert, butthe scan I had at 5 weeks, and the scan I just had at 7.5 weeks - even I could see how it had grown.... So 6 wweeks would be a huge difference.

BTW I gained 3 days on my 2nd scan,she said it is common.

Answer 2

I really really really really really really doubt that they could get it wrong by 6 weeks!

Why does it matter so much?

Answer 3

An ultrasound in the 1st trimester shouldn't be off by 6 weeks... unless there are significant defects in the baby.

Otherwise, 1st trimester ultrasounds are something on the order of +/- 3 - 5 days (so a 3 day difference in two seperate ultrasounds is totally expected).

Answer 4

Don't think by 6 weeks... but a few days, yes.  My identical twins used to come up as one day off all the time, we would just laugh.

6 weeks is a whole cycle plus the size of the baby would be VERY different.  

Answer 5

Nothing is really exact. Those dates are just estimates.

Answer 6

They are always just guessing by using your last period date, the levels of hormones in your blood, as well as your fetus size. But those again are just "best guesses" but ...........being off by 6 weeks..which is one and a half months!!!!....I dont think they could be off by that much!!!!!!!!!!!!

Answer 7

OHHHH Yes they can.  I had two babies that were 10 month babies but I think they actually got the date of conception wrong.