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how accurate are conception dates

A 29-year-old female asked:
Dr. Ryan Phasouk
18 years experience Family Medicine
Accurate: Dates of delivery are in general very accurate. Given a normal pregnancy and and an accurate history of the last menstrual period, it would be safe t ... Read More
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A 18-year-old member asked:
Dr. Michael Fox
34 years experience Fertility Medicine
Very: If done by ultrasound and correlated two to three times in subsequent weeks, it is probably within 2days. If it is a single measurement, it would be ... Read More
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A 28-year-old female asked:
Dr. Yvette Kratzberg
24 years experience Pediatrics
Fairly accurate : Evidence suggests that ultrasounds more accurately predict your due date than using your last menstrual period—but only in the first trimester and ear ... Read More
A 23-year-old female asked:
Dr. Gerard Honore
29 years experience Fertility Medicine
Not a percentage: First trimester us is usually considered to be accurate within a week, or +/- 3-4 days. There is no percentage implied, it doesn't work like that. In ... Read More
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A 24-year-old female asked:
Dr. Clarence Grim
57 years experience Endocrinology
Conception date: Not possible to tell except by DNA testing of child and possible fathers.
A 19-year-old female asked:
Dr. Miguel Cano
30 years experience Obstetrics and Gynecology
Approximate: Depending on how your due date is determined there may be a large margin of error. Early ultrasound (between 7-12 weeks) is the most accurate and you ... Read More
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A 23-year-old female asked:
Dr. Robert Kwok
33 years experience Pediatrics
Accurate in a range: Ultrasound pregnancy dating gives a date and a range. The date is an estimate. That means the date is not a single point in time. So, when an ultrasou ... Read More
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A 22-year-old female asked:
Dr. Jane Van Dis
18 years experience Obstetrics and Gynecology
11/14/13: Based on the information you provided, the 'average' date of conception would be appx 11/14/13. While 11/25 could be the conception date, it's highly ... Read More
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A 29-year-old female asked:
Dr. Piotr Obara
14 years experience Radiology
Yes: Ultrasound dating is most accurate early in the pregnancy using the crown-rump length (crl) of the small fetus. The measurement can be done starting ... Read More
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A 48-year-old member asked:
Dr. Dennis Higginbotham
30 years experience Obstetrics and Gynecology
Probably: The conception date should be about 2 weeks after the first day of the last period. The best way to know if that is accurate is with an early (less t ... Read More

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