Due Date uncertainty/US pic

toodaloo · November 2014

Yay! So I finally had my first OB appointment. Everything went well. Heartbeat was at 170. But, with my LMP, I should have been 10 wks 6 days with a due date of 4 June 2015. The ultrasound measured the baby at 11 wks 5 days with a due date of 29 May 2015. I asked her if we are going to change it and she said that 6 days isn't really enough, but to just go with a range. I am thinking what! I don't know about you guys but I look forward to my ticker change days. This is our 4th child, and my other children were delivered earlier each time. I know a due date doesn't mean baby will be delivered that day. I assume that ultrasound dating would be more accurate. Would you go with your original date, or the ultrasound date?

ac5008 · November 2014

LMP alone is fairly inaccurate. If you knew when you ovulated I would go more with that date, but I would go with measurements over LMP any day. If your other kids were early you probably ovulate quite early in your cycle.

finchfeeder80 · November 2014

My OB explained to me Monday that she uses the first ultrasound to determine EDD. After that, they take measurements to check the development and what not, but after that first u/s, they do not change the due date. I got the feeling that they use your LMP in comparison with the u/s to make sure you're not waaaay behind or anything like that, but she seemed to lean towards the actual u/s measurements they took more so than LMP. Hope that helps a little!

kelseygaona · November 2014

I would go with u/s date.

veggiemo · November 2014

bintmejnuna said:

If it were me, I'd just go with the original date and then see what the anatomy scan looked like later on.

The anatomy scan is actually less accurate than the early ultrasound, as far as due date. The further along you get in the pregnancy, the less accurate they can be with dating. If I were you, I would trust the ultrasound date over LMP

KikiCohen · November 2014

ac5008 said:

LMP alone is fairly inaccurate. If you knew when you ovulated I would go more with that date, but I would go with measurements over LMP any day. If your other kids were early you probably ovulate quite early in your cycle.

I agree.

mamahawk12 · November 2014

LMP. If your cycles are regular it's unlikely you ovulated 6 days earlier than you think. Ultrasound dating is notoriously inaccurate. Mine will only change a due date is two consecutive ultrasounds show baby as being 10 days or more off, in either direction.

blu-eyedwife · November 2014

So with my first, they were adamant about sticking with my LMP, even though I ovulated later.

With this one, they're going off the ultrasound, which is, like you, showing me to be a little farther along than I should be (based on both LMP and ovulation) I didn't think they were going to change it, because it's less than a week, but they did.

That's kind of a long backstory, but for me, I'm going off the date of the ultrasound. (But so is my doctor, so I'm not sure if that answers your question)

maggiegreig · November 2014

The opposite happened to me last night! I was at exactly 10 weeks last night based on my LMP and then based on the measurements in the ultrasound they said I'm closer to 9 weeks. So they moved my due date to June 16, it was originally June 10. I find this strange bc that would mean that I ovulated a whole week late and that I would have been under 4 weeks pregnant when I got a BFP. I know it doesn't really matter but the logistics of it have sent my OCD into overdrive! Lol

delujm0 · November 2014

maggiegreig said:
The opposite happened to me last night! I was at exactly 10 weeks last night based on my LMP and then based on the measurements in the ultrasound they said I'm closer to 9 weeks. So they moved my due date to June 16, it was originally June 10. I find this strange bc that would mean that I ovulated a whole week late and that I would have been under 4 weeks pregnant when I got a BFP. I know it doesn't really matter but the logistics of it have sent my OCD into overdrive! Lol

I regularly ovulate day 19-20 (except for the cycle I got pregnant...that was day 31) and got a +hpt at 3w4d. So what you are saying is entirely plausible.

My 8 week scan showed me measuring 3 days ahead based on my ovulation date (2 weeks behind if you used LMP)...The doctor went with that. It's probably a day or two off, even if I implanted pretty quickly, but whatever. Babies don't know their due dates and just show up whenever they feel like it anyway. :-)