The million dollar question: when will the baby arrive?

[Bloom]

As my EDD approaches I've been hearing lots of information/myths/opinions about when the baby will arrive. Of course, babies will arrive when they are good and ready. Some take longer, some take less time. I'm quite happy to just wait and see (not many options really!).

But I heard/read two interesting tidbits:
a) A friend of mine told me that the majority of 2nd babies arrive before their EDD.

b) An article on about.com said that some studies have shown that for Caucasian women with no complications, it is more accurate to add 10 days to your EDD for 2nd babies and 15(!) for 1st babies.

Does anyone have any actual information/statistics on this?

Thanks!

[*TripleJ*]

for me both wrong first bubba was 2 days "early" second was 3 days "late" (if u can call it that it definately felt like she was wayyyyy overdue lol)

[beckoes]

dd1 was born 41+5 weeks with a s&s and dd2 was 42 weeks with a s&s. i could have probably gone another two or three days with both without the s&s. but thats just my personal experience, never heard anything to back up those things

[kristi14]

For me personally ive found it to be a "weight of the baby" thing.

Most of mine have had to be induced because of various reasons and me being high risk but those i went into labour spontaneously with interestingly were all pretty much the same weight. #2 was spontaneous at 38wks exactly, he was 7pd3 (3260gm), #3 was spontaneous at 37+3wks, she was 7pd1 (3210gm), #7 i went in to be induced but im sure i was already in labour because i had been having different cramps and as soon as they broke my waters i went straight into regular contractions and he was born 1hr 15 mins later (I was also 3cm stretching to 6cm when they broke my waters), anyway that was 38+1wks and he was 7pd1 (3200gm).

So my theory is my body has a 3.2 to 3.3kg weight limit and as soon as my babies get to this weight range i go into labour. All the rest of mine were smaller than this weight and had to be induced.

[ladybird11]

I believe the baby will be born when the baby is ready

[onthefly]

Yeah, most of the time they just come when they're good and ready.
Mine were both 42+ weeks. I have read that the 'real' gestational period for humans is actually more like 41 weeks on average, so that about.com article might be accurate?
I did also read that girls tend to have shorter gestations than boys. One study I read the abstract for reckoned that correcting for girl twins, the average gestation was around 41+3 weeks.