Due Date Confusion

fkennard · March 2016

Has anyone else had this problem...........................

So my original EDD, based on my LMP was 9/13/16, I knew this wasn't correct though, for a number of reasons. Then at my first US the baby was measuring with a due date of 9/9/16, based on my cycle, when I know I ovulated, and when I am pretty sure I got pregnant, this seemed accurate. However, my OB office doesn't change the due date unless it is +/- 6 days from the EDD based on the LMP (which seems so silly, because that is such a "rough" estimate). Anyway, today at my 12 week NT/anatomy scan the baby measured with a due date of 9/5/16!!

I'm just curious, how what info does everyones OB use to date their pregnancy??

jln27 · March 2016

They asked for my LMP each time I went in (several ER visits + OB visits) but went officially off of ultrasound measurements. I don't suppose it matters too much because the baby will come when it's ready or when it's determined to be necessary, regardless of estimates.

mamadomino · March 2016

My doc is going with 9/27 based on lmp, even though I know I ovulated 3 days after that, and my ultrasounds are 1 day after the ovulation due date. But really, I'm having twins and there is zero chance we will make it to any of those dates anyway.

camichael84 · March 2016

My OB uses the dating u/s at 8 weeks, and sticks with that. I've read it's most accurate between 7-11 weeks and can still be off by up to a week. Like @jln27 said... in the end it doesn't matter. It's all an estimate and baby's going to come when it's ready.

618mom22boys · March 2016

I wouldn't put much stock into a dd anyways. My 1st I was given 2, he came smack in the middle. 2nd came at 38 weeks and 3rd came at 36 weeks.

KristinUM12 · March 2016

My midwife actually asked me if I knew the date of conception before she said anything about lmp...and I did know, so she just based my DD right off of that. 9/25! It was so nice to feel like she appreciated me knowing my own body so well, and Baby is measuring right on time of that date!

seitzy3 · March 2016

Mine goes off the DD they get from my first ultrasound measurements. At 7w little measured with a 9/1 DD. At 11w they said she was measuring around 8/27 (which would be accurate according to my chart) but I'm just keeping the original 9/1 due date. I'll most likely deliver in August anyway. Both my girls were early birds so not sure this one will stick around. We'll see!

madmyluv · March 2016

Just had my 12 week scan yesterday and I was measuring for edd 9/9/16 but at my 8 week it was 9/13/16. Dr said they will keep the 9/13/16 edd because it's more accurate during my 8 week then 12 week ultrasound.

fkennard · March 2016

Knottie10282924 said:

My midwife actually asked me if I knew the date of conception before she said anything about lmp...and I did know, so she just based my DD right off of that. 9/25! It was so nice to feel like she appreciated me knowing my own body so well, and Baby is measuring right on time of that date!

That's awesome! My doctor, was pretty much like, Nope, this is how we date the pregnancy - end of story. I really wanted to use a midwife, but there just aren't a ton of options where I live, unless you want to deliver at home.

fkennard · March 2016

Thanks for the input ladies! And at the end of the day, I know it REALLY doesn't matter, but it's my first pregnancy, and I just want a due date

EscoMama · March 2016

Sometimes it matters, like I need a scheduled C-section. Thank fully my dates are all matching within just a couple days.

fkennard · March 2016

seitzy3 said:

Mine goes off the DD they get from my first ultrasound measurements. At 7w little measured with a 9/1 DD. At 11w they said she was measuring around 8/27 (which would be accurate according to my chart) but I'm just keeping the original 9/1 due date. I'll most likely deliver in August anyway. Both my girls were early birds so not sure this one will stick around. We'll see!

I was born on 9/1!

tinypikachu · March 2016

They don't really worry about it because it is an estimate and babies can have growth spurts and measure for one DD on one ultrasound and then for another at the next and then stay there, keep changing or level out. It's a baby, so its size is not an exact science. If they changed it with each ultrasound, they would have to change it everywhere on your chart and it would end up all scratched up and the baby will probably not come on any of those dates

That being said, my office is the same way. I've had 5 ultrasounds and at each and every one baby has measured 4 days ahead (not once, not twice, 5 times consistently) and they still don't change it. The new due date would be precise according to my O day. Meh... i wish they would, I'd be 4 days ahead!

vampirina · March 2016

My doc basically does it the same as yours. My first due date was based off my LMP, but at my early dating scan (which we thought was 7 weeks) it was measuring about a week behind, as I suspected as my more recent cycles were a bit off, and since it was more than a 5-6 day difference they changed it. I have no clue how baby was measuring at 11 weeks because they didn't say, but I think at this point the due date will stay the same regardless, since it's really just an estimate and some babies end up a little bigger and others a little smaller, so it's pretty tough to know precisely when he or she will want to make an appearance!

mommytimesfour · March 2016

My OB uses the date based on LMP unless the dating scan shows a date +/- 7 days. My scans put me one day earlier than my LMP so there's not enough difference to change it.

camichael84 · March 2016

fkennard said:

Thanks for the input ladies! And at the end of the day, I know it REALLY doesn't matter, but it's my first pregnancy, and I just want a due date

I'd pick one (probably the 9/9 since you think it's right) and stick to telling people that and letting it be your EDD in your mind. With my first, my OB came up one day off from what my O day EDD was. I still went with the EDD Fertility Friend calculated and the only time the other date came up was at one or two appts.

Moxie1986 · March 2016

I had almost the same exact experience as you, OP. At our 10 week ultrasound the tech asked "are you absolutely sure of the date of your lmp?" - which I knew with 100% accuracy. According to LMP, my DD would be 9/13. But I also accurately remember my, umm, "activity" around that time, which leads me to believe I must ovulate a little early in my cycle. At 10 weeks I was measuring 5 days ahead - which lines up a little better with my belief about ovulation time and conception date, but she said they don't change a due date for only a 5 day difference. Then at our 12 week scan (we got a few extra ultrasounds due to previous loss) we were measuring even more than 5 days ahead but she didn't specify how much.

Hopefully it's not a huge deal and I know baby will come whenever ready anyway, but since I have a large-ish fibroid they want to monitor it closely and I know there is the potential for complications down the road and the possibility of needing to deliver via c-section. I'm not sure if that changes anything but I'm still confident that I'm in good hands. It can be a little confusing though!

So I guess we're both still 9/13 for now - unless your OB changes their mind!

Ampip2270 · March 2016

Here's a kicker for u ladies, I got pregnant w/ out a LMP... I was still nursing #1. So upon discovery of our pregnancy, I calculated my EDD to be 9/1 based on ovulation date. At my first dating scan, my OB estimated my DD to be 9/5 (done around 8 weeks) and at my 12 week scan they said EDD was 8/28. I think my OB did officially change my EDD to 8/28, but I still think it's 9/1 because I was using Ovulation Test Kits to track and I know when it was positive and when we BD on/around that day. But again, it's all relative and I actually feel better about this pregnancy not having a set DD. W/ #1 I was "expecting" too much based on a DD and this time it feels better just kind of winging it.

BernieRae · March 2016

I don't think it will matter much in Septmember, but for now I just want to see the weeks going by so a day or 2 matters! My RE gave me an EDD of 9/27 based on when my IUI was (ovulation was also medically triggered). At my OB appt they seemed to want to go by LMP which would make my EDD 9/29. At my last ultrasound with the RE I was measuring ahead by one day so that would be 9/26. Since hearing the RE's EDD I've been marking Tuesdays as the day I start a new week so I'm going to stick with that.

myjessesgirl · March 2016

Most providers won't change the EDD unless it's a week off or more. And it honestly makes no difference in the end. I always measured a few days early on my u/s with DD but ended up 8 days later than my LMP EDD (which was 12 days later than my u/s EDD). And they are eager to monitor you the later you go, so if they notice any issues past 40 weeks, they're usually very cautious. I am now doing the same thing with LMP and u/s EDD, but I'd rather assume I will just go into labor late anyway. I just have in my head that, although LMP says 9/19 and u/s says 9/15, I'll likely still be pregnant on 9/24! Lol

ducks6 · March 2016

Based on LMP and my 30 day cycle, EDD is Sept. 11. I had a dating ultrasound at almost 10 weeks that put EDD on Sept. 12. My IPS ultrasound put my EDD at Sept 7. My midwife is using Sept. 12 because I'd rather not be induced and this will give me the most time to go into labour naturally. She said "best to use the latest one." Love her!!

irishblessings916 · March 2016

My EDD by my LMP was 9/6. But at my 8 week appt baby measured 9 weeks. My OB said it was 7 days difference, so he changed it to be 8/31. My son came 2 days early from his EDD. But I was 100% sure of my LMP with him. This one, could be off by a day or 2. So much was going on at that time and my cycles were a few days off from my normal 26 days.

ahackett1990 · March 2016

My initial due date was based on my LMP. Then, when I was far enough along for an US they changed it and it seemed to be much more accurate based on when I think I ovulated. I've had a couple more US since then and I measured further along than that first US. But they just kept my EDD as 9/15. Hoping it comes a day late and it will share a b-day with my DH

LeahKnits · March 2016

@Ampip2270 I didn't have a LMP either. I was nursing my third baby, and we were using condoms so the pregnancy came as a total shock. I was actually at the OB's office to get a prescription for birth control when I got my BFP. They did a test before writing the prescription, just to be sure, because I wasn't having a period yet. They had me schedule a dating ultrasound right away. I'm overweight, and it could have been possible that I was quite a few weeks along. I was worried I was already into the second trimester. But thankfully, I was only a 5 weeks. My dd is September 10th.

I think it does matter. Especially at the end. But then, I've never given birth without being induced. I had low fluid with my first, pre-eclampsia with my second, and my third was c-section because she was very stubbornly breech. I did the c-section as soon as I could. Which was 39 weeks. The Dr gave me the option of waiting until 41 weeks to see if she just might turn on her own. But she was a big baby already and the chances of her turning were slim.

TheTamedShrew · March 2016

I knew I O'd on CD 17 so I lied that my LMP was 3 days later. It was actually an accident because I got the dates mixed up when I scheduled my first appointment, but I'm glad my due date is right on par with when I know I conceived. Baby has been measuring pretty close to the EDD at both appointments. I would suggest changing it to the 9/9 due date since baby is now measuring 8 days earlier than your original due date. I doubt it will really matter too much though unless you were measuring like 2 weeks off.

jensou · March 2016

I read something once that said only one in 20 babies are born on their actual due dates. So (if that stat is correct), we've got a 5% chance of having the baby on the EDD we're given. But- counting down to a specific date sure helps. And I agree when it comes to estimating baby's maturity and readiness to be induced, the more accurate the better.

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