What date would you go with to work out when to induce?

I have been given three different due dates over the course of my pregnancy.

My first (and the one I've tended to keep for myself) was based on the date of my LMP which was 24th May 2008. This gave a due date of 28.02.09 assuming a 28 day cycle. My cycle after coming off the pill varied between 28-30 days (over a 6 month period).

The very first ultrasound I had at 8 weeks gave a EDD of 02.03.09.

A later ultrasound (I think it was at 13 weeks) gave an EDD of 28.02.09.

My last ultrasound at 20 weeks gave an EDD of 26.02.09.

My doctor has always gone with the date of the latest ultrasound. So for the whole second half of this pregnancy, he has been working off the 26th as my due date. I haven't really argued because it was only a difference of a couple of days and I didn't think it would be that important.

Fast forward to now and I have been booked in for an induction on Monday night (09.02.09). The doc says I will be 11 days overdue by then. This was with my consent at the time because I had started to worry about fluid levels and placental functioning but now I am having second thoughts that this could be too early and I should wait until later in the week. I might only be 9 or even 7 days overdue based on the other dates.

I somehow always knew I would go overdue but I didn't think I'd be contemplating induction. The synto scares the cr@p out of me! Which due date would you use to work out how overdue I am?

Thanks for any replies!

I would go with the latest date. According to US and LMP I am supposed to be due on the 18th, but I know when I Oed and my MW is happy to go with my O based date. If you are concerned you can ask for a wellbeing scan to make sure bubs is fine.

They always went with my LMP date with me. Even tho bub was measuring just ahead dates at every scan.

I would go with the last date possible to avoid rushing baby along. So that would be 2nd March. Early ultrasounds are supposed to be the most accurate for dates anyway so I think it makes it a logical choice of dates.

Thanks for your replies girls. I have been told that all of these dates are "accurate" as they're all 'early' in the preg (i.e. first half) but I have also read that the really early scans are the most accurate.

I think I will try to get an u/s tomorrow and then, if all looks ok I will push the induction back a few days. The doc wanted an u/s done on Friday but it was nearly 3pm and he couldn't get me in so then somehow we were talking induction on Monday. After I left I felt a little rushed. I also want to know if he thinks there is some medical reason for needing to deliver this baby sooner.

If you also ask for a fetal heart scan (cartiography/CTG) then your doc/the midwives can assess if bub is happy and healthy. It can then become a pretty good tool for negotiation! I was reading the policy for induction at the women's (it is online) and they suggest that if an expectant mother does not consent to induction by 40 +14 then they are to be offered the CTG scan every second day to ensure bub is ok. It is really in your hands, you can push for only having an induction if there is medical necessity. Good luck :)

I'd go with the March date because your potential 30day cycle does allow for that, and 8w ultrasounds tend to be more accurate than others because its dealing with a stage of foetal development that is very precise, where as the later ones are pretty much going by sizes. I think we have all managed to adequately establish that babies come in many different sizes.

Thanks girls!

Bronners - Ta. You've raised a good point about hospital policy - might ask what that is in relation to refusing inductions when I see or speak to the doc tomorrow.

Inertia - It makes sense that the further you move from the point of conception, the greater the variability in growth and development and the range of 'normal' just gets wider after they're born!

Kaz - I also remember my doctor advising me that the earlier 12 week scan is more accurate when determining a due date or date of conception, precisely for the the greater the variability in growth and development after this point. I am sure there would be more about this online.
The policy for induction at the royal women's is here if you are interested: Induction of Labour CPG
I have found it a very interesting read as my first bub was born 40 +14 (went into labour the day before) and I was due to attend an induction appointment on the day of my DS birth. I feel more informed about the process hospital's go through reading this info, just in case I have a long gestation with this bub too!

Thanks Bronners.

I spoke to the doc this morning. He said there is no clinical reason for needing to start an induction today so I'm going to spend part or most of the day down at the hossy having the fluid levels checked, CTG monitoring and (because I think I've just developed PUPPS in the last few days) a blood test to check my liver functioning. I don't have appointment times so will be waiting for them to fit me in but I don't care. I feel so much better getting more information before inducing.

I still feel a bit frustrated with myself that I didn't negotiate all of this on Friday in his rooms. I've done a lot of reading and know to question, question, question but then, on the spot I didn't and just went along with what was being suggested. Better late than never I guess :)

Hope everything went well today Kaz :)

Thanks Bronners. It did actually. I have enough amnio fluid to just about cover two pg women!! Levels at the 97th percentile and I was described as polyhydran! All the other stuff came back good (BP, babies HR, regular uterus tightenings and baby movements). So the doc said that if I came in for CTG monitoring every day, he is happy to let me go until Friday morning before inducing. By my dates I will then be 41+6 so I am happy with that.

Felt SO much better yesterday to have been given more time and to have more information about what is going on with the baby.

And now I feel doubly glad I questioned the plan because I have been awake since 4am with what feel like mild contractions (not 100% sure) that are coming every 10-12 minutes. Even if this is a false alarm, it seems that my body is getting ready to do this on it's own without intervention.

Thanks so much for your support and information re: induction and scans etc. Much appreciated!

Good luck Kaz, and good on you for doing your research and questioning your care provider for what is best for your baby :)

I hope your contractions are the start of something good :D

Thanks Tanya.

I've been told they're pre-labour pains. Not quite strong enough or regular enough to be contractions but hopefully I am on my way and under my own steam. I never really fully understood when women talked about their instincts (I got it in an intellectual sense I think) but now I really get it. I just knew inducting last night was the wrong thing to do. If it wasn't for BB and the stuff I have learnt in here I might have just ended up going along with the suggestion (also had my mother encouraging an earlier induction rather than waiting).

Good luck Kaz, Lets hope the keep going and do some excellent work!!

Good luck Kaz, sounds like things are happening and labour won't be too far off :)