Please explain pregnancy dating/ '9 months' for us once and for all... ?!

[ddsmummytobe]

DP and I just can't work it out. Currently 22 weeks, so I'd say 5 1/2 months? But if 5 1/2 months now wouldn't that make us 9 months at 36 weeks, rather than at the full term 40?

So confused! Please help deboggle our poor ignorant minds!

Going back to the first day of my last period and counting forward 9 months I'd say 39 weeks classed as 9 months. There are slightly over 4 weeks in a month so you need to take that into account when trying to convert weeks into months. I'd say you were just 5 months rather than 5 1/2 right now.

It's very rough (back in the days when dating a pregnancy wasn't possible or even thought of).

With DD1 I got pregnant in June and she was due in March.
With DD2 I got pregnant in July and she was due in April.

Roughly 9 months each time.

Pregnancy should be counted in weeks. That is what all the healthcare professionals use.

1 month is more than 4 weeks but less than 5 so no exact conversion..

It can be easier to use months when chatting with friends. In this case just count back from due date. So if you are due on 1 June you would be 8 month 1may, 7 months 1april etc.

Don't try and convert directly between the 2 it doesn't work.

If you are counting in months then it ought to be easy. My pregnancy is dated from my lmp of 7th July so I would go up a month each month on the 7th, which would make the pregnancy 9 months plus a week or two.

Your system would make pregnancy 10 "months" long if you go up a month every four weeks.

Just count in weeks, it's easier.

There are 13 weeks in every 3 months, I think most books/ Internet planner things divide this into 2 four week months and one five week. So you're actually 5 months and 1 week, and you'll be 6 months at 26 weeks rather than 24.

It's the same for babies, who are 3 months old at around 13 weeks rather than 12.

HTH

When counting for myself I count in weeks, with 40 weeks obviously being due date. But if talking to someone who doesn't work in weeks, will use months and use my due date as the marker. So I'm due on the 4th June, so every 4th of the month I go up by one month. You can't do an exact conversion from weeks to months as there are a different number of days in each month.

Ahh yes, thank you, that makes perfect sense We've only come across this dilemma as trying to re-think dates in ways that make it sound less long to go IYSWIM... So, for example, the other day I worked it out in days (ridiculous, I know, as unlikely for due date to be actual date), and found that currently stands at 124 days to go. 124! Sounds forever!

Think you're right it's time to go back to sticking to weeks, nice and straight-forward. Just seems to be going soooooooo slowwwwwwwwwwwwwwly...

Agree with blushing - I work back from my due date. I wouldn't work forward from my period as you still wouldn't end up at 9 months exactly on your due date if you did it that way.

40 weeks is actually 9.2 months (or something like that) so it's a bit inaccurate to say 9 months.

I have a friend who calculates a month as 4 weeks until it becomes inaccurate. She does it in pregnancy and baby age. So her son is 12 weeks old (but three months by her calculation), but when he gets to 48 weeks old (12 months surely?) she stops using weeks and just says he's 11 months. A bit bonkers and we're always disagreeing about it.

Here's a link to confuse matters event further - www.baby2see.com/pregnancylength.html