How is due date calculated on MAT B1 form?

[jennie1818]

Help! I just found out we are pregnant on the first try! Whilst I am really happy I am also a bit stressed now as after reading the company's policies I found out that I will only be eligible for the enhanced maternity pay if completed 52 weeks by the qualifying week.

I input my due date into the NHS calculator and counted back and I would have JUST completed 52 weeks based on my current predicted due date. However if this date moves forward by more than 3 days I will no longer qualify for enhanced pay which makes a big difference.

How to not stress!! Will I be okay/will they usually have leeway +/- a few days given the inaccuracy of this all anyway?

Bumping for you. Not an expert but thought it was based on the 12 week dating scan. I assume you haven't had this yet.

You'll get a rough estimate at your booking appointment, mine was originally the 8th May and then when I had my 12 week dating scan it went to the 5th May, and that is now the one that they are sticking by. You dont need to tell your employer till 25 weeks very latest anyway so you have time to figure our your due date and plans financially for either situation. Hopefully you qualify!! Some companies dont offer enhanced, I only get SMP x

On both of my 12 week scans I have been put ahead by 2 days each time (knew when I ovulated).

When you say qualifying week is that definitely the due date week?

The qualifying week is like 15 weeks before your due week, based on counting back from the Sunday of your due week (overly complex I know). How do you know when you ovulated and how does that impact the calculation of your due date? I know the rough week I was ovulating but I don't know the exact date I conceived (could be like a weeks range..).

How did your final due date compare vs first day of last period + 280 days? That's what I've gone off at the moment

Did you try and calculate the due date before via last day of period + 280 days? Or is that how 8th May was derived? I calculated mine as 1st October... if subtract only 3 days it should be 28th Sept which is still okay... just worried it falls to anything earlier and then I will miss out on quite a substantial amount as its 4 months paid leave :(

LMP is only used right at the beginning as a rough guide - it's based on a very average cycle and ovulation so not accurate for everyone (my official due date and date based on LMP are 10 days different!)

You will get your official due date at the 12 week dating scan - that's the date the midwife will use for the form

It’ll be based on your 12 week scan. For us it brought our due date forward by 4 days from the date my lmp had predicted.

LMP becomes irrelevant once you’ve had your NHS dating scan. The scan determines your due date, for example I know exactly when I ovulated and conceived but my scan and so whole pregnancy was dated 1.5 weeks later, now a perfectly healthy 9 month old

Exactly this. It doesn't matter when you ovulated or when your last period was really. It'll only make a difference at your booking appointment for a rough date. At your 12 week scan you'll be given a date based on the baby's measurements and this is the date they'll use on your MATB1 form.

my 12 week scan brought my due date forward by 3 or 4 days, this is the date used for my MATB1 form

The date on your Mat B1 will be set from your 12 week dating scan - there won't be any leeway in it as you only get given it after 20 weeks I think, and due dates aren't adjusted with future scans unless there's a huge discrepancy.

How long have you been employed at your current job?

OP it Definitely goes off your 12 week scan, LMP for my wife was 25th July but baby at dating scan measurement the date changed to 22nd July.

All fetuses before 14 weeks develop at the same rate which is why the dating scan scan only be done then. Otherwise bigger and smaller babys would affect things.