Are first borns lighter at birth than their younger siblings?

[Posey]

In my extensive research (well asking around friends ) it seems that most first babies are lighter than the next ones. My first was 9oz lighter than my 2nd, and dh and I, both 2nd born, were substantially heavier than our older siblings.
Is this your experience? How did your babies weights differ?
Does anyone know if this is a recognised fact or is it just the case with the people I know? Is there a reason for this?

My first born was the heaviest of my three, but that might have been that he was 5 days overdue, whereas the others were 10 and 9 days early respectively. DS1 was 7lbs 6oz, DS2 6lbs 12.5oz and DS3 7lbs 5oz. I don't do particularly big babies, not by today's standards anyway. DS3 is looking to be the tallest/biggest build of the 3.

I've always thought this was the general rule, but that's only based on hearsay so it'd be interesting to know if it's a scientific fact! My first was just under 9lb and second was just over.

Ds1 weighed 9lb 8oz, while ds2 weighed only 9lb. However, ds1 was induced at 41 weeks while ds2 was induced at 38 weeks so I suppose my second baby WOULD have been bigger than my first if nature had been allowed to take its course.

Hope that makes sense!

My firstborn was actually the lightest of my three at 6'8, the others were 7'3 and 7'7 respectively..lol!

Spacemonkey (yes I am stalking you through the threads) mine were the same weights as yours exactly but the other way round, second born slightly lighter

Thank goodness, no. My eldest was 9lbs 4oz, youngest (and next) was 8lbs exactly. Both born on their due dates, btw.

My first was 2 lbs heavier than his brother!

DD1 - 5.11 (41 weeks)
DD2 - 7.12? (40 weeks)
DS1 - 8.3 (38 weeks)
DS2 - 7.4? (37 weeks)

(All caesarians.)

Sorry about question marks - can't believe I have forgotten!

DD1 grew up under 25th centile, and DD2 above 75th, but they ended up the same height and weight. DS1 has been 50th throughout but was late developer and at 15 is just shooting up. DS2 is c 90th for height, but skinny.

Older brother, younger brother and I were all between 9.12 and 9.15 I think.

Obv I come from a very random family!

dd1 6lb 6oz 39 weeks
dd2 6lb 10 oz 37 weeks
ds1 8lb 38 weeks
ds2 6lb 4oz 36 weeks

DS1 7lb 11oz
DS2 8lb 5oz
DS3 8lb 4oz(with nappy on, don't know why MW didn't weigh him without it)

Not sure of our weighs but my brother was the first and heaviest, then my sister next and then I came along last and was the lightest.

DD1 was 8lb 2oz - at 41 weeks
DS1 was 8lb - at 39 weeks
DD2 was 8lb 12 1/2oz - at 42 weeks.

8lb 8oz @ 40+3wks
8lb 8oz @ 41+3wks
7lb 5oz @ 41wks
7lb approx @ 39+6wks

baby #1: 3.06 kg
baby #2: 3.77 kg

Am I the only metric person?

Well there goes my theory

Mine was.

Ds 5lb 7oz (on due date)
Dd 6lb 12 (and a half!)oz (4 days early)

no 1 7lb 11 2 weeks late
no 2 7lb 8 oz 2 weeks early
Technically debatable!!

Me: 2.92 kg, then 3.25 kg (just to make SP happy).
Friend: 9lb10oz, then 8 lb8oz.
Aunt: 10lb, 10lb, 8.5lb, 10lb.
Cousin: 6lb13oz, 9lb12oz, 8lb10oz.
DH's cousin: 8lb8oz, 8lb8oz, 9lb10oz.

Only ones I can recall not involving twins. The pattern just looks all over the place, to me.

no1, girl, 6lb 15oz, born on due date
no2, boy, 9lb 4oz, born 5 days after due date
no3...? we'll see

ds1 was 6lb 2 days early and ds2 was 6lb 8ozs 3 days late.

Dd 8lb 7oz, on her due date
Ds 9lb 1oz, but he was two weeks early! No diabetes in pregnancy, he was just plain big!

DD1 8lb 8½oz - 42wks
DS 9lb 1½oz - 41wks
DD2 7lb 7½oz - 40wks

DS (first born) 10lb exactly, DD 9lb 8oz.
so no BUT, DS was 15 days late

That's how it was with us. DS1 was 7lb2, and DS2 was 8lbs.