Depends: 1st trimester US is accurate within 5-7 days so if it differs from your LMP due date by more than that then the US is used. Also if you are uncertain about your LMP, most OB's will use that early US.
Answered 8/30/2014
3.8k views
A doctor has provided 1 answer
A doctor has provided 1 answer
4 doctors weighed in across 2 answers
3 doctors weighed in across 2 answers
A doctor has provided 1 answer
90,000 U.S. doctors in 147 specialties are here to answer your questions or offer you advice, prescriptions, and more.
Ask your question