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A member asked:
Do ultrasounds add two weeks & should they theoretically date back to your lmp?on 12/6/13 baby measured 12w4d, crl was 60.9mm.if go back 12w4d should that date to(or close to) my lmp?when was conceptn?
3 doctors weighed in across 2 answers
Gestational dates: Are based from your lmp. If the average female has a 28 day cycle, your ovulation is about day 14. But that could vary by 2-4 days easily. If you only had sex once during your cycle and you got pregnant, you'd know for sure when you conceived. But if you had sex a couple times or more during your mid cycle, that makes it much harder to pinpoint the day.
Answered 2/19/2014
4.4k views
Yes: Ultrasounds do add 2 weeks, as you suggest, because pregnancy dating is based on your lmp, not your conception date. If on 12/6/13, your baby was measuring 12w and 4 days, then your 'average' date of conception is +/- (5 days on either side) of september 23. Hope that helps.
Answered 3/31/2014
4.4k views
Related Questions
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People also searched for:
Do ultrasounds add two weeks to date back to (or close to) your lmp?
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