Join the Meeting Place for Moms!
Talk to other moms, share advice, and have fun!

(minimum 6 characters)

2 Bumps

Is using an early ultrasound (14 weeks) more accurate than using LMP to determine due date?

I know when my LMP was, and that indicates that I am due Feb. 2, The earliest ultrasound I got said EDD was Jan. 25...Until now when my midwife was measuring fundal height it agreed with my LMP. Now all the sudden I am measuring with the measurements of my first ultrasound...If you're educated on this subject please help me out!!! (but than again I think he may be measuring bigger because he is breech, he was in the frank breech position, but now I am assuming maybe footlong breech)


Asked by amberpatterson at 2:57 PM on Jan. 10, 2011 in Pregnancy

Level 16 (3,170 Credits)
This question is closed.
Answers (5)
  • I had no idea when I had my last LMP so when I had my first ultrasound at 15 weeks (I know, I didn't know I was pregnant for a while) they gave me an EDD of March 20th which gives me an aproximate date of conception of June 27th......and last LMP of June 13, which made sense to me once I thought about it. BUT ultrasound dates can be off, which is why every baby isn't born on their due date. Also baby will come when it wants to anyways, only 5% are born ON the EDD!

    Answer by shanapiv at 5:44 PM on Jan. 10, 2011

  • Ultrasound is more accurate early in the pregnancy. But Jan 25 and Feb 2 are only 1 week apart.

    Answer by Snewo at 3:12 PM on Jan. 10, 2011

  • 14 weeks isn't an early ultrasound and could definitely be off. Fundal measurements also aren't exact. That said, the dates are only a week apart, so it doesn't really much matter. I'd go with the later date and baby will come when he/she comes.


    Answer by LeanneC at 3:29 PM on Jan. 10, 2011

  • I will tell u that the dr does not care what the ultrasound says. They care about lmp. any time mine has been different they use lmp

    Answer by LuvMyMedic3ID at 3:35 PM on Jan. 10, 2011

  • "Early ultrasound" is usually considered in the first trimester, generally 8-10 weeks or so. The earlier the ultrasound, the more accurate the estimate. And keep in mind that fundal height is even less accurate than a late ultrasound; my fundal height changed 3 cm once in one appointment because my baby changed position.

    Since your dates are just a week apart, and that's really just the middle of a 4-5 week range anyway, it really doesn't matter. If you plan on scheduling a C-section or induction, I would go with the later date, just to be on the safe side, but otherwise it doesn't matter at all.

    Answer by DragonRiderMD at 5:51 PM on Jan. 10, 2011