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A member asked:
Do first trimester dating scans change lmp to match ovulation day and make cycle 28 days?
A doctor has provided 1 answer
No: The first trimester dating scans are the most accurate of all scans. Since many women guess at their LMP and are often wrong, the ultrasound EDC is compared to the EDC from LMP. If it is less than 7 days different, it is considered consistent and the EDC remains the same. If the dates are >7 days, we defer to the ultrasound and change to due date to the new one created from the ultrasound.
Answered 9/15/2020
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Related Questions
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Is u/s dating in first trimester more accurate that going by LMP? EDD changed & going by ultrasound now...
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What does it mean when LMP dating by ultrasound in first trimester assumes a 28 day cycle?
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Does dating scan lmp go by 28 day cycle. What if i ovulated late?
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Lmp was 16th apr but dating scan at 9 weeks says it was 22nd apr. Does this mean i ovulated late. Anatomy scan at 20 weeks said lmp was 19th apr?
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Lmp was 16th april does this mean i definitely ovulated on the 30th april. or should i go by dating scan saying lmp 22nd may & ovulation 6th may.
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People also searched for:
I had a first trimester scan at 6wks+4 days and my CRL measured 6wks+5 days - does this mean i ovulated/conceived around day 14? My LMP was 14th Feb
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