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A member asked:

How often are first trimester ultrasounds off in dating conception?

A doctor has provided 1 answer
Dr. Gerard Honore answered

Specializes in Fertility Medicine

Off?: Depends what you mean by 'off.' the theoretical accuracy of a 1st trimester us is considered to be +/- 2-3 days, so in that sense they are always 'off.' if you mean wrong, as in more than 2-3 days, no one knows this - but with a skilled sonographer and a current us machine, it shouldn't be off by more than a few days very often.

Answered 2/28/2019

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People also searched for:

I wanted to know how accurate early ultrasounds (first trimester) are in conception dating? If i was 5 weeks4days 9/23/13 putting conception 25-28 of aug could I have still concieved 7/28/13
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