Top
25
Doctor insights on: How Accurate Are Dating Scans

Share
3

3
How accurate are early dating scans mine came back 6weeks 5days due 23 October and my LMP was on 13/1/14 due date 20th October ?

How accurate are early dating scans mine came back 6weeks 5days due 23 October and my LMP was on 13/1/14 due date 20th October ?

Conception: Early scans are the most accurate and most used way to determine conception and due dates. You can verify all you need to know about your pregnancy yourself on the internet. The tools are readily available. Your baby was conceived on 1/30/2014 from sex that occurred 1/25/2014 to 1/30/2014. You can verify this here: http://www.babymed.com/conception-calculator. ...Read more

5

5
How accurate is a dating scan performed at 13 weeks pregnancy?

How accurate is a dating scan performed at 13 weeks pregnancy?

Should be ok: Dating ultrasound scans have good accuracy at 8-11 weeks, so one done at 13 weeks should still be reliable. Dates by ultrasound are always estimates. ...Read more

7

7
Why did my 9 week scan change my lmp date? Did i ovulate late. Is that what happend? Is dating scan at 9 weeks accurate to find ovulation?

Why did my 9 week scan change my lmp date? Did i ovulate late. Is that what happend? Is dating scan at 9 weeks accurate to find ovulation?

Scan likely accurate: A 9 week scan should be accurate at getting our best idea of a due date, although it is within normal range to deliver anytime between 37 and 41 weeks....so even our best guess isn't that "accurate". And yes, if the scan made your due date later, then you likely ovulated later. Ovulation time can vary even with fairly regular periods. ...Read more

9

9
Does my due date from dating scan at 9 weeks give an accurate day of when i ovulated. My lmp was 7 days earlier than dating scan said it was.

Does my due date from dating scan at 9 weeks give an accurate day of when i ovulated. My lmp was 7 days earlier than dating scan said it was.

Sure LMP: is the best dating criteria for pregnancy. If you are sure of the date that you first started your LMP, then that is the best predictor of when your baby is due. ...Read more

12

12
How accurate are dating ultrasounds?

Depends: 1st trimester +\- 5 days 2nd tm +- 10 days 3rd tm +- 21 days. ...Read more

13

13
Are 11week ultrasounds accurate for dating? Margin of error?

Varies: The range of error for an ultrasound at that point would likely be around +/- 8 days. ...Read more

See 1 more doctor answer
14

14
my dating scan 1st August 2014 dated me 12w 5days who is the dad? the one on the 20th april or the second on the 29th april til middle of may?

my dating scan 1st August 2014 dated me 12w 5days who is the dad?  the one on the 20th april or  the second on the 29th april til middle of may?

Second one: Thirteen weeks is a trimester, or 91 days, which puts your date if conception around the 3rd of May. Since there is an error factor of +/- 5d - 2weeks, you will probably need to do paternity testing, since within this error factor, either one could be the dad, within the error if the testing technique. Dad #2 is the front runner in this calculation, but can't rule out #1 by dates alone ...Read more

15

15
I had a dating scan yesterday I am 4w3d. I didn't feel nauseous that much and my nips still are sensitive but not as much can symptoms come and go?

I had a dating scan yesterday I am 4w3d. I didn't feel nauseous that much and my nips still are sensitive but not as much can symptoms come and go?

Yes: Absolutely! It's early, so symptoms will wax and wane for a couple of weeks then set in. Every woman's experience is different ...Read more

16

16
Are ultrasounds accurate at dating conception at 12 weeks?

Are ultrasounds accurate at dating conception at 12 weeks?

Much more than: Later in gestation. First trimester ultrasound is most accurate at estimating gestational age within 5-7 days (depends on the center). It trails off after that. General rule: 2nd trimester scans for dating are +/- 14 days and 3rd trimester is the least accurate (+/-21 days). ...Read more

See 1 more doctor answer
17

17
Does a nhs dating scan measure the baby to your LMP or when you conceived?

Does a nhs dating scan measure the baby to your LMP or when you conceived?

Do not know what: Nhs scan means but any ultrasound during pregnancy will date the gest age , 7-10 weeks is usually the most accurate the farther u get like the 3rd trimester the larger the range is. ...Read more

18

18
Can 12 week dating scan be off by 2 weeks? Could a 10 week gestational age fetus measure as big as 5.6cm?

Can 12 week dating scan be off by 2 weeks? Could a 10 week gestational age fetus measure as big as 5.6cm?

Yes: Ultrasound scanning is related to the skill of the sonographer. Typically a 10 week scan has three days of error built in when the test is performed vaginally. There is more error with an abdominal ultrasound. Average crown rump length at ten weeks is approximately 3-4cm. ...Read more

See 1 more doctor answer
20

20
20 week anatomy scan gave due date 3 days earlier than dating scan done at 9 weeks. which due date should i go by? Are they both wrong?

20 week anatomy scan gave due date 3 days earlier than dating scan done at 9 weeks. which due date should i go by? Are they both wrong?

The ultrasound: A second trimester US is much less reliable than a first trimester one. In this case, they are very consistent which makes your dating very reliable. Go with the 9 week ultrasound date. You did not mention your LMP, but if it is also consistent with the 9 week sono, that makes your dates even more reliable. ...Read more

22

22
Which male could be the dad. 20th april or beginning of may as dating scan dated from 3rd may but baby was born 4th feb 4 day early from EDD?

Which male could be the dad. 20th april or beginning of may as dating scan dated from 3rd may but baby was born 4th feb 4 day early from EDD?

Either guy could be: From April 20 to May 3 is 2 weeks, which can be too close to call. It doesn't matter when the baby is born, if the original dating ultrasound was within the reliable dating time earlier in pregnancy. One can do this the old-fashioned way, meaning the father is the guy the woman married... and live happily ever after. Or, if one must know exactly, one can just save up for the cost of the DNA tests. ...Read more

24

24
Will dating scan at 9 weeks give a later lmp than actual lmp if i ovulated later than day 14?? Should i use dating scan to find ovulation date?

Will dating scan at 9 weeks give a later lmp than actual lmp if i ovulated later than day 14?? Should i use dating scan to find ovulation date?

9 week sono: A 9 week sonogram is very accurate. It has a margin of error of only about 3-5 days in experienced hand. If you have due date given by the sonogram you can type that date into a free online reverse due date calculator. This will show you the date of conception. ...Read more

25

25
Should i go by lmp or dating scan at 9 weeks? Dating scan changed lmp date to 6 days later than it actually was. Is this because i ovulated late?

Should i go by lmp or dating scan at 9 weeks? Dating scan changed lmp date to 6 days later than it actually was. Is this because i ovulated late?

That's the same date: In pregnancy dating, all dates for natural pregnancies are estimates (plus or minus a week). That means 6 days earlier than a presumed date, or the presumed date, or 6 days after the presumed date, ARE ALL THE SAME DATE. That's how it works. They are the same day. But, if a woman only had sex ONE time, she knows her conception was likely 1-5 days after that. Dating scan at 9 weeks is accurate. ...Read more