Due Date Changed by 4 Weeks at Scan - Anyone Else?

[themacsmum]

Hi

Last week I had my dating scan and was told that I was 16 weeks rather than 12 weeks that LMP indicated . LMP was a bit unusual in that hubby and I had decided to stop trying for a bit so I went back on the pill on first day so only had one day of bleeding however I can't seem to find anyone else who was so much further ahead.

I really worried as to whether I can rely on the scan dates or not as I was induced with my 1st baby and this is something I a really keen not to repeat if possible yet the chances seem high if docs go by scan date but LMP estimate is more accurate. If there a danger my baby could be induced prematurely?

I'd love to hear from anyone who's been in a similar situation

themacsmum

How feasible is it to write off what you had down as your LMP as an implantation bleed? Could you have conceived the month before?

(I'm a bit confused by when you were taking the pill - after the LMP that would have you at 16 weeks or after the LMP that would have you at 12 weeks)

I would trust the scan date more than the LMP date.....the scan goes by size of the developing embryo/foetus.
LMP is all a little subjective. It does sound like your last LMP may have been an implantation bleed, though not everyone has those.
With ds my cycle was very long due to irregular ovulation, so my LMP date was 3 weeks earlier than the scan date. I know i ovulated later that the average '14 days' as was using ovulation sticks.
DS did actually arrive on the due date according to the scan! arriving on due date is a little rare however this proves for me that the scan date was more accurate.

Thanks tangle and sons mum. I feel more ressured about going with scan date now. Think bleed that I though was LMP (and when I started taking pill again) must've been an implantation bleed. Didn't have anything like that with my son so didn't even enter my head this time.

Thanks again

If you were taking the pill from the 1st day of the "LMP" that would have you at 12 weeks and you then took the pill according to instructions for the entier month, I'd say you're almost certainly closer to 16 weeks.

Congratulations, btw

As an aside, if you do find yourself heading towards you hospital's induction date again you might want to read up on expectant management approaches to being overdue. There are always risks and benefits to any course of action that you should make sure you understand before making a decision, but you don't have to be induced just because you've got to 41 weeks and that's when your hospital policy recommends it

I think your LMP was in fact an implantation bleed. This happened to me with ds, I had just come off the pill, ttc straight away had a very light period. The following month we didn't ttc, I needed to take some medication so took a pregnancy test first as the medication wasn't suitable for pregnancy and it was positive! If we had ttc the second month I would have assumed that I was only 4 weeks rather than the 8 weeks that I actually was.