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what is the margin of error for due dates based on early ultrasound

A 39-year-old female asked:
Dr. Timothy Davis
24 years experience Radiology
Gestational age: It is reported as number of days that gestational age could be off, in days. Assuming that babies all mature similarly (a fairly good assumption with ... Read More
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A 31-year-old female asked:
Dr. Bruce J. Stringer
46 years experience Radiology
What year?: It would seem that you would have to conceive on feb.. 8, 2014 to give birth on 10/31. If the question is of historical interest, i would need to know ... Read More
A 39-year-old female asked:
Dr. Jeff Livingston
21 years experience Obstetrics and Gynecology
Same date : A four day difference is mathematically speaking no difference. You are within the margin of error of a sono machine. A due date simply marks the gest ... Read More
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A 38-year-old female asked:
Dr. Joseph Accurso
28 years experience Radiology
7-13 weeks: The most accurate measurement for dating is the crown-rump length at between 7 and 13 weeks gestation.
A 35-year-old female asked:
Dr. Alan Patterson
41 years experience Obstetrics and Gynecology
Not compatible: Conception occurs the day of or within 2-3 days of interourse.
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A 39-year-old female asked:
Dr. George Klauber
Specializes in Pediatric Urology
Among others Yes & Y: Also maternal fetal obs and experienced obs.
A 31-year-old female asked:
Dr. Liza Kunz
Dr. Liza Kunz answered
20 years experience Maternal-Fetal Medicine
Yes, fairly accurate: The margin of error on a dating scan at 13 weeks is approximately 7 days.
A 30-year-old female asked:
Dr. Gerard Honore
28 years experience Fertility Medicine
Yes if: 1) the pregnancy's abnormal and hence not the correct size, 2) the sonographer mismeasured or miscalculated. Otherwise, not really.
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A 30-year-old female asked:
Dr. Neeoo Chin
39 years experience Fertility Medicine
Conception: The most likely dates of conception are either october 28, 29th, or 30th.
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A 39-year-old female asked:
Dr. Nikolaos Zacharias
25 years experience Maternal-Fetal Medicine
+/-1 week.: First trimester sonography is more accurate than even certain menstrual dates due to inherent variation in ovulation. The degree of accuracy at 12 wee ... Read More
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A 32-year-old female asked:
Dr. Jeffrey Levine
30 years experience Family Medicine
Mid January. : If EDC is accurate , then your last Menstrual period was likely around 12/28/16, and you likely conceived 2-3 weeks later.
A 24-year-old female asked:
Dr. Karen Dantin
36 years experience Family Medicine
All: General calculations are based on last period, but in uncertain dates measurements are crucial
A 31-year-old female asked:
Dr. Jie Xu
Dr. Jie Xu answered
16 years experience Obstetrics and Gynecology
Vaginal: Transvaginal ultrasound is more accurate in first trimester, with a margin of 5 to 7 days. Hope this helps.
A 30-year-old female asked:
Dr. William Coutts ii
25 years experience Family Medicine
Ovulation: The menstrual cycle is very structured. The first day that you bleed is the first day of your menstrual cycle. You ovulate or release an egg from one ... Read More
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A 29-year-old female asked:
Dr. Jeff Livingston
21 years experience Obstetrics and Gynecology
Online calculator: Use a free online reverse due date calculator. Type in your due date and the conception date will be calculated for you. The margin of error on an 11 ... Read More
A 30-year-old female asked:
Dr. Saptarshi Bandyopadhyay
20 years experience Hospital-based practice
All of the above.: I am not an Obstetrician, but as I understand it, no one measurement is "most accurate" for fetal age. That is why all are measured together - some so ... Read More
A 51-year-old female asked:
Dr. Michael Sparacino
36 years experience Family Medicine
Stretching it: That's stretching it!
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A 29-year-old female asked:
Dr. Dale Kristle
39 years experience Gynecology
+/- 1 week: The accuracy of an 11 week ultrasound should be +/- 1 week.
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A 28-year-old male asked:
Dr. Jane Van Dis
17 years experience Obstetrics and Gynecology
Depends: If a woman is thin and the doctor has a good image of the fetus, then abdominal can be just as accurate as vaginal. Margin of error at this gestation ... Read More
A 30-year-old female asked:
Dr. Steven Weissberg
54 years experience Obstetrics and Gynecology
10/28-11/6: Last week of october to first week november.
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A 30-year-old female asked:
Dr. Anthony Filly
25 years experience Radiology
Need more info: What was the date of your ultrasound. And on that day, what did they estimate the gestational age of the baby to be.
A 39-year-old female asked:
Dr. Bruce J. Stringer
46 years experience Radiology
Depends: For an early sono the LMP is less significant since early on, the sono dates are felt to be more accurate. If a patient shows up in the third trimest ... Read More
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1 thank

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