Advanced search

Pregnant? See how your baby develops, your body changes, and what you can expect during each week of your pregnancy with the Mumsnet Pregnancy Calendar.

EDD by scan v EDD by dates/LMP

(36 Posts)
Cariad007 Tue 11-Feb-14 11:11:31

Has anyone else had a 9 day difference in their due date by scan and by dates? I was told 24 February when I saw the midwife at my first appointment and this was revised to 15 Feb at my 12 week scan. Which turned out to be a 13+5 week scan instead. I accepted this at the time but now that I'm coming up to my official due date I'm starting to worry a bit. If baby doesn't arrive within a week of my scan date then they'll want to talk about induction, which I am very against, especially as I've got a good idea of when I conceived. I know I don't have to consent to anything I don't want to, but could do without the stress if it came to that.

My partner and I are both fairly tall (5'9 and 6'4) so I'm wondering if our baby is just a bit longer than normal? My bump still doesn't look full term - I had to have a growth scan at 29 weeks and baby came out bang on average for measurements and then at 36 weeks I was measuring fine for dates. Yesterday I had to go to the hospital briefly and they measured my bump at 37cm, which is about 2 weeks behind what I should measuring (though I know bump measuring isn't an exact science!) though the midwife didn't think anything of it.

So I am dong everything I can to bring on labour but was just curious if anyone else had had the same happen to them and if so, which date the baby arrived closer to?

x0gawjus0x Tue 11-Feb-14 11:26:05

By dates mine is 8 days before my edd from the scan, she is actually measuring over average too, I have growth scans fairly often.. They're never mentioned anything about it to me

Cariad007 Tue 11-Feb-14 11:29:04

See, I wouldn't mind so much if it was that way around as they go by scan date but I shall mention it to the midwife again if it comes to a question of induction.

fruitpastille Tue 11-Feb-14 11:44:30

Similar here. Also measuring small for dates, but I did for previous pg too. Hospital a bit dismissive of my dates but did say that ultimately induction etc would be up to me and they could only advise. As it turns out I need a section for breech and it is scheduled for 39 weeks, which by my reckoning is more like 37.5. However this is still 'term' and I am pretty sick of being pg! Also date v convenient for my dc to go to grandparents etc and I am not wasting mat leave waiting around, so am ok with this.

Cariad007 Tue 11-Feb-14 15:33:10

I almost think I'd rather have an ELCS than an induction as a few friends have had very bad experiences.

ASmidgeofMidge Tue 11-Feb-14 15:37:56

My EDD by scan took 7 days off my EDD by LMP. Like you I was pretty sure of dates so was sceptical. DS arrived at 40+6 and that was by induction for reduced movements. So closer to 'my' version of due date.
Fwiw, my experience of induction process was reasonably +ve (although I know others with different views/experiences).

addictedtosugar Tue 11-Feb-14 15:42:06

You don't have to agree to induction at 41+ X, as per hospital recomedations.
EDD by LMP only really works for 28 day cycles. if you are longer / shorter than this, EDD in not accurate.

But do look into why they recommend induction at this point, and what declining induction may involve - daily hospital checks in some places.

Have a fab time whenever your new arrival turns up.

WinterDrawsOff Tue 11-Feb-14 15:59:07

IME - (I've have four DC), EDD are just that, estimated. Each baby is different. I'm nearly 6' tall and my second was classed as small for dates, with a consultant telling me he will be under 6lbs and he ended up being over 9lbs! My third had an EDD of the 8th of May and she was born on the 25th April- perfectly cooked grin Scans are very hit and miss and if you were measured by two MW, they would probably come up with two different measurements.

I wouldn't worry too much about your dates. You know when you conceived, so don't let the MW and consultants bully you into an induction. Some women find them very unpleasant and you can run the risk of a "cascade of intervention" if you are unlucky.

Do your research and ask lots of questions. Good luck thanks

Heathcliff27 Tue 11-Feb-14 16:02:44

With my 3rd child I had dated myself as due 7th June but scans kept dating me as 29th May. I was booked for induction on 9th June and daughter arrived naturally on 8th June so my date was right.

Heathcliff27 Tue 11-Feb-14 16:05:52

Meant to add, weight wise she was no different to the other two, 1st child born 7 days early 7lb 3oz, 2nd child born day before due date 7lb 10oz and 3rs child was 7lb 3.5oz

DinoSnores Tue 11-Feb-14 16:08:36

"I wouldn't worry too much about your dates. You know when you conceived, so don't let the MW and consultants bully you into an induction. Some women find them very unpleasant and you can run the risk of a "cascade of intervention" if you are unlucky."

Be refusing induction, you can also run the risk of your baby dying! MWs and consultants don't recommend induction for a laugh! A "cascade of intervention" is not the most 'unlucky' thing that can happen! hmm

I've had an entirely uncomplicated induction (at 39 weeks for complications with the baby) as well as an entirely uncomplicated homebirth and an induction of labour for a stillborn baby. Induction is really not the worse thing that can happen!

Thatsnotmyfigure Tue 11-Feb-14 16:21:35

I'm in a similar position second time round. First time round I was induced. They wanted to start induction 10 days after due date, but I delayed till 13 days. It is worth reading the NICE guidelines on this. I felt very strongly and Im glad I delayed induction as I had a show before I went to hospital and ended up giving birth vaginally that night. Like you I'd heard horror stories of induction.
I also know when I conceived so am going to try to get consultant to look at dates with me. If I remember rightly you can delay induction for more than 2 weeks if you agree to be closely monitored as supposedly risks increase. Good luck

naty1 Tue 11-Feb-14 16:34:17

I do agree they should listen if you know when you conceived. But i believe the time taken for implantation can vary.
You even have to have dating scans with ivf babies which seems silly.
Maybe the induced babies are also generally bigger as they are overdue so even more likely to need forceps etc.
I started labour naturally but it didnt progress to had induction too, failed ventuose and forceps.
Baby was born 1 day before EDD.

sleepingdragon Tue 11-Feb-14 16:50:31

I did a bit of googling on this after my midwife had a confused moment at my booking in appointment and put my dates for 2 weeks later. She did later change them but I was interested in what would have happened if she hadn't. Scans can come up with different dates depending on the sonographer and the position of the baby, as well as the fact that all babies are different. Up to 12 weeks scans are considered accurate to within 3-5 days, amd between 12 and 22 weeks they are considered accurate to within 10 days, or so I read on a few sites.

Claryrocks Tue 11-Feb-14 17:32:37

We thought my due date would be later than scans said but obviously went with scan date. DS born 2 weeks early but he looked more than 2 weeks early. He had lots of saggy skin and his nails were still growing into his finger. He was skin and bones. We're convinced even now that our dates were right all along.

Cariad007 Tue 11-Feb-14 19:59:40

Thanks. This is all very useful. If I don't go into labour this weekend I will be writing a letter to take to the midwife at my appointment next week laying out all the reasons why I think my scan EDD is wrong. I'm apparently 39+3 today and I've not even lost my mucous plug, which I gather can happen any time from 36 weeks.

DinoSnores Tue 11-Feb-14 20:29:21

You can often not lose your mucus plug until you actually go into labour, so I wouldn't use that as a reason to assume that you are behind where your scan says.

Cariad007 Tue 11-Feb-14 20:37:23

I'm not - I'm using what I'm pretty sure are conception dates and LMP dates, which the midwife used to calculate my original EDD.

naty1 Tue 11-Feb-14 21:32:43

I think bump measurements can be quite out i measured small and had a 7lb 10 and so did someone else i know and had a 8lb baby.

AlwaysDancing1234 Wed 12-Feb-14 09:43:39

With DS1 I ended up with 3 different dates!
I knew my date (and pretty much time) of conception as everything was closely monitored and recorded at the time. After various scans I finally ended up with them saying either the 8th or 12th of the month for EDD, he turned up on 21st weighing over 9lb so neither my dates or theirs or their estimations of weight were particularly accurate!

AlwaysDancing1234 Wed 12-Feb-14 09:44:45

And for what it's worth I didn't lose my mucus plug until I was in labour a few cm dilated

naty1 Wed 12-Feb-14 10:00:21

I didnt lose mine my waters broke at 36+5

HopeS01 Wed 12-Feb-14 10:06:58

You don't have to be induced, you can just wait, so nothing to worry about thanks

Blondebrunette1 Wed 12-Feb-14 10:13:43

They don't tend to induce you until 10-12days after the date given to you by scan (where I am anyway.) So you will still be over the due date you have in mind. My scan date is 5 days earlier than my calculation, all I would say is they know what they are doing and I'd not try and hold out as last time I was 16 days over until they could induce me (no beds or doctors) and was made fully aware that placenta was running out of time and wouldn't be working as efficiently-I was terrified. I also thought my scan had put me ahead but when he arrived he was very dry skinned and I was told it was because he was in too long. The induction process is also not as straightforward as you'd expect, they try pessaries first and they only work if you are ready (they did nothing for me) they didn't break my waters or give you a hormone drip until the last min or at least they didn't go down that route until last min with me. Also it was not bad at all ime, sure everyone is different. I'd just say stay calm and ask questions and find out your options but ultimately they want what us best for you and baby.x

DinoSnores Wed 12-Feb-14 11:48:20

"You don't have to be induced, you can just wait, so nothing to worry about"

Your baby dying as a result of placental failure that happens more commonly post-dates (stillbirth rates start rising at 10 days post EDD) is perhaps something to worry about.

Join the discussion

Registering is free, easy, and means you can join in the discussion, watch threads, get discounts, win prizes and lots more.

Register now »

Already registered? Log in with: