Explain to me why babies are overdue....

[dontlaugh]

Ok, I am currently 38+ weeks pregnant. I was wondering if I go over my due date, is it because I have miscounted my own dates (certain of period date, fairly certain of ovulation date, implantation date not sure) or is it because baby is genuinely too cosy?
Are all pregnancies 280 days? (Or 266 from ovulation?)

(brain sizzles slowly....)

A due date is just there to guide your care. A baby takes somewhere between 37 and 42 weeks to gestate. Just as different women have different menstrual cycles, different women take different amounts of time to make a baby who is ready to be born. You're not 'overdue' until after 42 weeks.

There is not real thing as a due date. In general babies are born between 37-42 weeks. I think the due date is used for medical reasons and maybe work reasons too?

In France the gestation period has been officially changed from 40 to 42 weeks because so many babies are born after 40 weeks.

cross posts with you showofhands!!

Oooh, speedy responses, thanks.
Will desizzle and ponder that. I have a short cycle and am thinking this one may show up a bit earlier, we'll see.

I think it's because nobody's told the baby they're expect on a particular date. Otherwise I'm sure more would make an effort to be on time

Well, if they're in line for a throne they'd better learn to be on time katie

dontlaugh Don't laugh but I thought the same thing about my baby, I'm 40 weeks on Wednesday and no signs yet :(

Boo, jburge. Still only Monday, mind! best of luck with it.

Thanks, I hope yours does come early! I have known a few babies arrive a few days early recently, I think that's why I convinced myself that mine might!

Dd was 10 days late, no confusion in dates of conception, but even so she still came out covered in vernix, so I don't think she felt she was properly cooked I was sort of induced as was having some contractions and thought my waters had gone, so they gave me the gel to get me going properly! I think she would have happily stayed in there a bit longer!

The 280 days is just an average. Going on the laws of mathematics, half of babies will therefore arrive after this average date and half before. Although I think with first babies in particular the stats are skewed in favour of lateness.

Might be me being a bit thick but I thought it was also affected my the fact they date your pregnancy from your LMP?

E.g mine was 31st Dec and I pretty much know I conceived on 14th Jan but I was still technically 4 weeks pregant when I found out (actually 2 weeks after implantation)

Think I'm going to take my EDD with a pinch of salt and expect little one to come 2 weeks later I think and may be be in for a shock!

Spice, you're not being thick at all, it is a strange thing to get your head around but how a pregnancy is dated isn't really relevant.

All pregnancies are dated from 2 weeks prior to conception. For some women this coincides with LMP (if she fits the average, textbook model of LMP then ovulation 14 days later).

A baby is due between 35 and 40 weeks after it is actually conceived. But we date a pregnancy from 2 weeks before this so pregnancy is more commonly referred to as between 37 and 42 weeks, with the 40 week EDD just a fairly arbitrary date in the middle.

LMP is only relevant until the first scan anyway as not every woman follows the textbook 14 days between LMP and ovulation.