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A member asked:
How accurate is an altrasound in guessing how far along you are when 1st done around 18 to 20 weeks?
2 doctors weighed in across 2 answers
Fairly accurate: The sonogram takes into account several different measurements at that stage (length of the leg bone, circumference of the head and abdomen, width of the head) and averages those measurements to come up with an estimated gestational age. These measurements should be within a week or so of each other and are a good predictor of the age.
Answered 9/12/2013
4.9k views
Very: At 20 weeks gestational ultrasounds are accurate to within a few days assuming a healthy pregnancy.
Answered 9/12/2013
4.9k views
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If an ultrasound was done at 14 weeks is it accurate?
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