How accurate is an ultrasound dating scan?

Question

I had one and they put me at 12 weeks 6 days, can they really tell to within a day?

They did one 2 weeks earlier but said the baby was too small to accurately predict the age

Answer 1

I was told when they changed my due date that an ultrasound gives a far more accurate due than going by our cycle. My guess is that they could be off by a couple of days but they are looking very close at development and size which does not vary alot this early in pegnancy. I would say they are pretty much right on!
congrats of your pregnancy! : )

Answer 2

12 weeks is quite late for a good estimate.
I had one done at 8 weeks and due date matched exctly the date that was calculated by the last period date.
at 13 weeks, they were off by 6 days (becasue at this point they estimate by the baby's size, but some babies grow faster and other slower)
The doctors usually consider the first date, which should have been estimated around week 8.

Answer 3

my ultra sound scan shows me being 10 days off my period prediction but when i questioned the fact that i knew the exact date of my last period they said they go by how the baby has developed in size and movements so i might have a fast developing baby i dont think anything is that accurate the baby will come when she wants to

Answer 4

What you will desire to remember is that dating scans are purely predicted, and might grant you the incorrect dates, yet its not that often in any respect that this does ensue. with my first toddler, one test confirmed twenty 9th September, yet another confirmed third october, it certainly relies upon on the size of the infant aswell judging how precise the test is, babies advance is diverse expenditures in pregnancies i grew to become into perplexed approximately mine aswell which grew to become into my 2nd infant this 300 and sixty 5 days, because of the fact the medical doctors and midwives predicted me as being due twenty seventh would this 300 and sixty 5 days, yet each and all of the scans confirmed i grew to become into due 5th June, infant nevertheless got here a week late, The bleeding you experienced would have been implantation bleeding, yet you additionally could have sessions for the period of being pregnant, yet all and sundry is diverse.

Answer 5

In my experience they were accurate they were spot on, with my first son I was six weeks further on than I thought! Although they also give you a due date and none of my due dates were right although my second son was a day later than my due date, my third son was 12 days late,and my twins came two weeks early

Answer 6

I have had 2 children and they were spot on with each one - I knew the day I got pregnant with both of them and the scans were the same dates as mine.

Answer 7

My scan was a match with my ovulation dates... I think though they can show differences if your baby grows faster or slower... My guess would be that you might see some changes if scans were done every month...

Answer 8

they werent too bad for me, and they do usually tell you weekplusday. which is quite cool, my friend though she was dated but it worked out tht her hubby wasnt even in the county the week tht the scan had showed lol. but it levelled out again at the next scan
good luck

Answer 9

Not quite that close but very close