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A member asked:

Does 1st trimester ultrasound have margin of error up to 7 days because of the equipment/skill of tech or because fetus can grow at dif rates?

A doctor has provided 1 answer
Dr. Brad Douglas answered

Specializes in Obstetrics and Gynecology

Margin of error is: Margin of error is 8% - so it differs the longer you are pregnant...so for example at 10 weeks - you are 70 days pregnant - which 8% means a 5 to 6 day error. If you are 20 weeks - the error is 140 days x 8% which is about 11 days of error .....so you need to do math

Answered 10/21/2018

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Related Questions

A member asked:

Whats the error in a first trimester (9 to 12 weeks ultrasound made by skilled doctor, 3 of up to 7 days? Different awnsers by different doctors here

A doctor has provided 1 answer

A member asked:

If ultrasounds have margin of error, how do u know when you're within the range of when the NT scan should be done?Does fetus have to be certain size?

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A member asked:

What is the error of margin for an ultrasound dating at 11 week 4 day, measuring the fetus crl at 4.8 cm?

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A member asked:

Do all fetuses grow the same in the first trimester? Poss for a fetus to grow small & date multiple weeks behind? Ex actually be 12w, but date 8w?

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A member asked:

LMP was Feb 18, I have shorter cycles of 25/26 days. 3 first trimester ultrasounds gave me a due date of Nov 19-21 putting conception at Feb 27-29. How accurate are these conception dates? Anyway conception occurred before February 20?

A doctor has provided 1 answer

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