Tell a porkie re date of last period?

[Thatsnotmyfigure]

I've just found out I'm pregnant with #2 - hurrah!! I have a long cycle and typically ovulate on day 17 or 19. Pregnancies are dated according to date of last period based on ovulation on day 14. I know exactly when I ovulated and could therefore give the date of last period of my ovulation minus 14 days. Is there anything wrong with this?
The reason being that I was induced last time, which I had desperately hoped to avoid due to the likelihood of intervention. I ended up not in the birth centre, with more drugs than I wanted. The annoying thing was that I'd had a show an hour before I was told to arrive on ward so I know I was close to letting things proceed naturally.
They wanted to induce me 10 days over, I got them to postpone till 13 days as NICE guidelines say 14 days is fine. Since then there's been research done saying older Mum's have longer pregnancies anyway (I'm 41)
Crumbs that's very long-winded!! It probably sounds really trivial but it matters to me! Any thoughts anyone?!

they will go by your dating scan anyway, so it's a bit of a waste of time!
But in any case, you are not obliged to be induced! It's a suggestion they're making to you, following the guidelines they have- you can follow the suggestion or not as you choose.

Nope, I get where you are coming from - my cycle was 42 days and I'm 16 weeks now and LMP is still ruling by big green book. I even got slightly botched blood test results for the maternal serum test because they assumed a wrong date and all my levels came up lower than expected (duh!).

But they date by scan, anyway, and since the dating scan here happens at around 20 weeks I'm not too worried about getting a wrong date, they've adjusted my date backwards twice already (by ovulation it's 2nd June, by LMP 16th May), so I think by the end it'll be mostly correct, anyway.

I understand why you'd be tempted to though, with your previous history.

I told my mw on which day I ovulated and she calculated from that instead. Still, it makes no difference when they will go by what your 12 week scan says anyway. The lmp date is only a guide for the first few weeks before the dating scan.

If you want to refuse induction then you should ask for expectant management instead. They can't force induction on you.

Thanks everyone I didn't realise the scan was so important as last time they didn't adjust after 12 wk scan - they just kept due date the same. I got such a shocked reaction postponing my induction by 3 days - the mws made me feel like a real pain!

In The BW - that's such a big difference! Hope everything works out for you!

Not unreasonable at all. That was precisely my plan. I also had a private dating scan at 8 weeks to check my dates and fully intended to adjust my LMP date if necessary to make the discussions at the other end easier (turned out not to be needed). I've also heard of people changing their EDD in their notes themselves. If HCPs won't listen then what do they expect women to do?

Also, they won't always go by the nuchal scan. The nuchal scan has a dating accuracy of +/- 5 days (longer if they leave it late eg 14 weeks), so if you're sure of your LMP and you have a regular cycle they won't adjust your EDD for the scan if it dates within tolerance.

Thatsnotmyfigure, they've already moved me up to 26th of May at my Nuchal scan, so it should be ok in the end.

Hope you get it sorted, I'd just talk to the midwife about your concerns.

I considered doing this with dd2. With dd1 my LMP date & scan date were basically the same, but I knew my ovulation date which had her due at 42w... Guess when she arrived? For whatever reason - innate truthfulness maybe - I didn't fudge dd2's dates, & again LMP date & scan matches, but this time DC arrived at 40+1! So I think if there is a dc3 I will speak truth again.

I did this to avoid being hassled at the end, but they changed it after the scan. As others have said you can refuse induction.

Thatsnot, do you know which scan is used as dating scan in your trust? 12 weeks or 20 weeks? Might make a difference to your decision...

I did just that with my second pregnancy! I have short-ish cycles (25-28 days) with late ovulation (cd16-19), so the normal calculations would skew my due date quite a bit.

Sadly, it is also true that they finalise the due date after the 12w scan results (it's always 12w, never 20w, that decides; as after 12w babies grow at very different rates).

However as another poster said, you don't have to agree to anything. They had adjusted my EDD by a full week, and as I was trying for a VBAC I did not want to be induced. Plus I was sure of my dates and that they had it wrong! So I battled the consultants left right and centre; but finally went into labour on my own at 9 days over (in their books it was 16 days over!). He still had vernix on him and no shrivelled skin at all, so clearly he wasn't overcooked and I was glad he had the chance to arrive when he was ready.

Yanbu, but you do not have to be induced! You can just refuse

In my experience the LMP date is the one the me & other key people kept on going by even though I hand-crossed it out when it turned out there was about a week discrepancy against scan date! With my first pregnancy I missed being able to have nt test accurately done as pregnancy was further along than their lmp date suggested (op I have opposite issue to you with 21 day cycle). Every appointment that was booked, they went by the crossed out date. Unsurprisingly DS1 was born just over a week 'early'.

I tweaked the date I gave re the 2nd pregnancy so the dating scans etc were in time and funny enough accorded with the date I thought would be right. So if I were you op, I would massage the date you give them.

I did this and also declined the 12 week dating scan. I know when I ovulated and I know when I had sex.

DS was born at 37+5 so I wasn't going to risk them getting it wrong this time and being told I was in pre-term labour when I wasn't as I am planning a home birth. They got it pretty wrong at my dating scan in my first pregnancy.

The sonographer at my 20 week scan attempted to date the pregnancy, but the date she gave us would have meant we conceived five days before we had sex. My DH is pretty great, but I don't think he has time-travelling sperm!

GreatJoan My maternity notes say my Trust does the dating scan between 19w and 22w as it is considered more accurate according to current research, or something like that - so the 12w scan isn't the dating scan everywhere.

I'm a bit about it as the little bugger already looked quite big at the 13w private Nuchal scan I had...

Do it.

I learned the hard way with DC1. If I'd lied about my ovulation day (it was day 29, was temperature charting and got a BFP at 9dpo so very sure!) they'd have not adjust my dates. Instead they set them to what she measured at 6w5d, which was 6w2d. So my due date ended up being 3 days later.

You'd think it wouldn't matter, but I wanted a homebirth. At 36w6d I went into precipitous labour. As I was literally SIX hours short of the 37 week cut off they made me go in to hospital. The panic of the sudden labour and the ambulance transfer (I'd never been in an ambulance before) meant labour stalled and I didn't dilate fully. The incompetent bank midwife at the hospital told me to push and I didn't really feel like I needed to, but I did. For an hour. Whilst she yelled at me I wasn't trying hard enough.

After an hour she checked me and it turned out I'd been pushing against a lip. She moved it out the way and DC1 was born shortly after. She then administered the injection, which I later found out shouldn't be done with a precipitous labour as the uterus is too exhausted to push it out. Manual traction was involved, she claimed she got it all. We went home the next morning.

12 days later I spent three nights back in hospital with a postnatal haemorrhage and infection (guess she didn't get it all) on an IV.

A few years later I nearly lost DC2, it was just luck I had a cervical length check at 18 weeks and got an emergency stitch. DC1's birth basically trashed my cervix and I now have a permanent stitch placed through major surgery as of DC3 which I had to fight for but it turned out I definitely needed, this is DC4 and I will have had 3 c-sections. Major impact on my life and nearly cost me my children.

If I'd just lied about my dates at the beginning none of that would have happened, I would have had my homebirth with the nice community midwife who would never have rushed me into pushing when not ready nor administered the injection. When I talked to them about the birth when I was pregnant with DC2 they were not impressed with that bank staff hospital midwife at all.

I tell every woman to lie if she is sure of her ovulation because of the huge difference it can make. DC1 was ready to come, it was her time, a homebirth would have been perfectly safe, but they all thought she was early and she wasn't.

Crispy that's beyond awful

It's not great! I mean, obviously most of the blame would lie with the crappy hospital bank midwife, but I'd never have encountered her if I'd been allowed to have the homebirth that should have been perfectly safe. Mostly I'm cross I never had my chance for a do-over with a natural birth, but ultimately I'm realist enough to know I am extremely lucky to have my children now, partly due to realising I need to advocate more than I did before, and due to excellent NHS care too. It goes both ways!

OP- I fibbed about the date of my LMP for my first pg for similar reasons. I knew that I had ovulated v late and conceived v late because DH and I only had sex once that month. I just didn't want an argument about it and couldn't count on the 12 week scan supporting me. As it was, the 12 week scan confirmed that I was right and I went into labour on my due date. can't see any reason why you would be jeopardising the pregnancy in any way by doing it.

Congratulations on the 2nd pg by the way!

Crispy that's awful I just read your story - thanks for sharing

Thanks too fairy

I did the same. I know I ovulated on
CD24 so moved my LMP date by 10days. My dating scan put me one day earlier than my fudged date so I know I was right to do it.

I didn't fib about my dates, but my area is very much 'it goes by the scan'. My due date has been put forward by 8 days, despite me informing them it would be basically an immaculate conception to have those dates. Nothing I can do will shift them.

However, my community MW is understanding of my position and has promised that she'll make an appointment with the supervisor of MW's if I get towards +14 (which is when they recommend induction here) and I want to wait. I've explained I am happy to think about induction at +14, but not what a scan says is +14.