What's more accurate, U/S or going by your own data?

dale5689

Just wondering if anyone had a different due date from an U/S than what your cycle did.  My U/S is putting me a week earlier when compared with what happened with my cycle and when I think I ovulated and last period.  With my 1st pregnancy I'm pretty sure my U/S was a week earlier and I was positive when I ovulated because I was temp charting but then went 10 days early.  Just curious to know what happened with you girls.  Thanks!

Raffes484

My cycles are all over the place, so the ultrasounds were more accurate for me. With DD my own data only had me off by a week. With DS1 I hadn't had a period in over 3 months, so if I had gone by that date I would have been WAY off to say the least.

kagl04

For me I believe the ultrasounds were wrong with both my pregnancies. I just carry small babies. With DD, I should have been due 8/18, but ultrasound said 8/27. She was born 8/6 weighing 5lbs 10.5ozs. With DS, I should have been due 10/18, but ultrasound said 10/30. He was born 9/28 weighing 6lbs 1oz. Both times I fought it (DH and I know when we had sex and we planned both pregnancies) but it did nothing for me. Thank God too because my DS was born with respiratory issues and they had his gestational age as 35w2d and I had it at 37w. We had drs ready to check him out because he was a preemie in their eyes but if they went by my dates he would have been deemed full term and no one would have been there to help him at birth...

Arielle27

I was charting with #1.

With #1, my doctor went with the last period when calculating the due date, even though I was charting. It was about a week earlier than I would have thought, based on my cycle. At first the U/Ss matched my info, but throughout the pregnancy, they got closer to the last period info. DS was born 4 days earlier than the due date my doctor gave me initially, and it was obviously on time, not early (he was nearly 9 pounds!).

This time, my cycle was more 'normal' so the charting info/US/last period date are all within 2-3 days of one another.

In any case, as my doctor said, it is all within days different, not weeks, so it doesn't really matter. I think the later ultrasounds are the most accurate figures.

kcisthebombdotcom

Knowing exactly when you conceived doesn't guarantee you'll deliver at 40 weeks exactly. You went 10 days early because baby was done cooking 10 days early.

If you're going by when you *think* you ovulated, that isnt accurate at all. Stick with the u/s EDD and know your baby will come whenever he/she is ready.

laura1

In terms of u/s, a first trimester u/s is actually the most accurate.  They should never change your due date based upon a later u/s if you had a 1st trimester one.  As for accuracy between u/s and LMP?  I am not sure - if you have normal 28 day cycles, your LMP should be accurate.  But again, a 1st tri u/s is pretty accurate, so they should be relatively consistent.  

Qmommy

It depends on when the u/s was done.  If it was during 1st tri then I'd say that the u/s is more accurate.  If it was a later u/s (18-20 weeks) then I'd say LMP is more accurate.  

Based on LMP with DD1 I should have had an EDD of 5/20/10.  Based on my 1st tri u/s my EDD was 5/30/10.  Based on my TTC chart my EDD was 5/28/10. She was born on 6/4/10.

Based on LMP with DD2 I should have an EDD of 11/21/11.  Based on my 1st tri u/s my EDD is 12/6/11.  Based on my TTC chart my EDD is 12/6/11. We'll see with this one is born.

sometimesalwayschaotic

I have charted with both pregnancies.  With DD My LMP due date was Jan. 1 and my due date based on ovulation was Jan. 4.  I believe the ultrasound was somewhere in the middle of the two.  She was born on Jan. 4.  For this Lo I got a due date of April 15 based on charting and the ultrasound said April 16.  We'll see when he/she actually comes.