12 week scan changed due date to an impossible date - worried about impact on C-section timing

[duedateworry]

I tracked my cycle with LH strips, which pinpointed the LH peak / day of ovulation. Once pregnant, I had my HCG tested at 11, 13 and 15dpo. The results were exactly in line with what they should have been on those days.

At my 12 week scan, the due date was changed to be four days earlier.

This would mean I ovulated on CD8(!), and days before getting an LH peak. It also means that the HCG results (which they’re now saying were taken on days 15, 17 and 19 dpo), would have been completely out of sync with what they should have been.

I know the date they’ve given me is wrong and I’m worried that the c-section I need to have will be set for a date four days too soon.

Has anyone had any joy in getting the NHS to change a due date that is patently wrong?

I'd be interested to know though, when those studies assess the gestational age of the babies at birth, are they calculating using the date of ovulation (if known), the date of last menstrual period, or from the gestational age as assessed by the NHS? Because if the latter two, who's to say they aren't capturing people in OP's situation?

I suspect lots of people who fall pregnant don't know exactly when they ovulated and so due dates are necessarily not 100% accurate. When I was expecting my son, I knew based on when I ovulated that my 'due date' was 2 December. Based on LMP it was 29 November. When I had scans, they moved it forwards to 26 November. I ended up delivering by (emergency) C-section at 39 weeks according to NHS records, but 38+1 based on my ovulation date. I suspect in any study, he'd have been listed as a delivery at 39 weeks exactly. (He was absolutely fine, incidentally, no breathing issues.)

Obviously feel free to ask them about it, but I doubt a couple of days will make much difference - babies are all a bit different so it's not an exact science. It might turn out to be complete a non-issue depending on how your due date falls. For example, my due date falls on a Friday and my hospital doesn't do planned sections on Fridays or weekends, so the earliest I could be booked in was 39+3 anyway (booked for week 39 for medical reasons).

Trust the professionals. A baby is classed as term from 37 weeks so you will be fine if it’s a few days out

I seem to have the opposite problem! Should have been 12+5 at dating scan, but the sonographer said she couldn’t get the reading accurately and wrote down that I was 11 weeks. I’ve got to go back for another scan, but even though she said that date was wrong it’s been taken by receptionists and my midwife as accurate. Putting my due date impossibly late.

I had a NIPT over 2 weeks before and was 10+5 (which must have been correct or the blood test wouldn’t have worked), so I just can’t be only 11 weeks.

I really hope they change it next week, or there will be a knock on effect on my 20 week scan and my ELCS date. If they schedule that for 39 weeks on that date, I’ll actually be 41 weeks.

the date at the anatomy scan is more based on the baby's development rather than the date the egg fertilised. like people babies develop at different rates so in determining whether the baby will be developed enough for the C-section it's actually more accurate. They generally don't change the date once it's set at 12 week scan and it's very normal for it to measure up to a week ahead or behind.

and if set at 39 weeks there's no reason to think that the four days would make the blindest bit of difference. FYI my daughter was born at 34+1 and even that was 3 days ahead of what i knew it possibly could be and she had ZERO issues breathing and APGAR scores of 10! so please don't stress about it. it's really normal

I conceived via IVF during a medicated cycle which meant there were absolutely 0, nada chances that my dates were wrong. IVF clinic gave us Estimated Due Date which then was changed during my 12 week NHS scan, because they set your due date by factoring in baby's size & measurements.

My dates were changed by a whole week because baby was measuring big, and had a planned C Section booked at 39 weeks (NHS due date). Gave birth to a healthy baby boy bang on the 50th centile. He was technically early but a perfect size with top scores ❤️

You really don't have to concern yourself over your due date. They can change based on baby's measurement and size all the way out to your 20 weeks scan.

I had a 32 weeker for my first and was terrified of my second being 'too early' because dates changed around a lot during the pregnancy.

As a result they planned c-section for 39+3 and everything was fine, in fact he was bloody huge 😂

So if you are concerned I'd maybe just suggest speaking to the midwife / consultant and asking if it be planned for the last possible moment.

4 days is nothing. My section was brought forward to 37 weeks because I was very poorly. Baby was 8 pounds and needed no help. Kindly, you're worrying unduly and now you're as pregnant as you are, I wouldn't worry about ovulation day etc.

All. Y babies born at 38 weeks, no steroids, no issues with breathing. Was not even told tha pt was an issue when had a c section ( planned due to reach) a few years ago.

Days don't matter, weeks do. I had one at 36+5 and even though premature, she was perfectly healthy, didn't need help with breathing and when I mentioned for the weigh ins she was premature, they said, a couple of days and a good weight so it doesn't matter, won't correct weight or anything. 38+5 is fine, and even less likely you Will go into labour before your date.

I had steroids when I had an ELCS at 38 weeks exactly but from reading on here that doesn't seem a universal rule across the Uk. Chat to your midwife about it, I'm sure they'll be able to put you at ease.

I had a planned c-section at 38+3 - so issues at all 😊.

Good news, I was able to choose from a couple of c-section dates. I chose one where the NHS thinks I am 39w5d but really I will be 39w1d, thus out of the 38 week timeframe and significantly reducing the likelihood of baby being admitted to the neonatal care unit with breathing difficulties. Very pleased

There really isn't.

Baby might be small or maybe the measurements were few millimetres out.
Things will fair out ok

It's not 38 weeks. I don't know where you're getting that from.

Babies born before 37 weeks are considered pre term.

Anything after 37 weeks is full term.

I do wish people would read the full thread. Then you would know “where I was getting it from.”

The statistics and recommendations are different for babies born via c-section.

There really is.

According to NICE guidelines, planned C-sections should not be performed before 39 weeks of pregnancy unless there are health problems that affect the mother or baby. This is because babies born before 39 weeks have a higher risk of respiratory complications, but the risk decreases as the baby's gestational age increases. Waiting until 39 weeks also gives the baby's lungs and brain more time to develop fully.

Tommy’s: You will usually have a planned c-section at 39 weeks of pregnancy. Babies born earlier than 39 weeks are more likely to need help with their breathing.

NICE: Babies born by planned caesarean birth at term but before the due date are at a higher risk of respiratory complications. The level of risk decreases with gestational age, particularly from 39 weeks onwards. Therefore, planned caesarean birth should not routinely be carried out before 39 weeks.

@TheShellBeach @S1lverCandle HTH 👍🏻

Yes, it is from 39 weeks, based on evidence of outcomes. Which includes people who were given 'wrong' due dates. It's widely accepted they can be a week out. So 39 weeks will be 38-40 weeks in reality. If they said 38 weeks they'd have some 37 week ones in there that would be more likely to struggle.

So yes, OP is right that she wanted to be over 39 weeks. Which she was either way. She may have known that she was more likely late 38 weeks, but that's taken into account in the guidance as it was within the tolerance of the accepted level of variability.

My consultant told me recently it’s more risky to the baby to have a c section at 38 weeks than it is to induce and have a vaginal birth at 36 weeks. This is to do with mucus as passing through the birth canal helps their lungs get to work. So they are usually quite strict with making sure c sections are 39 weeks +

Completely anecdotal of course, but my first came via section at 38+2, scared the hell out of us coughing up mucas in the early hours of the morning at a few hours old. Second born via section at 39 weeks - no mucas in sight

Mine arrived at 41+2 via c-section. Coughed up mucus for a couple days. Scared living hell out of me. Was coming out his mouth, nose, complete projectile. I know at least 2 others in the bay did too.

OP is saying she’d be 36+3 in reality, making baby premature.

Yeah my 1st was born with IUGR at exactly 37 weeks and she was the same, she was full of mucus for weeks. My 2nd is being born soon and will be 38+4 so I’m interested to see if there’s a difference for us