f/u twin question...b/g, g/g, b/b

suh5969

I know b/b is the lowest chance but what is the other order?  I am googling away but not finding the answer!

suh5969

I am of course talking about fraternal twins...

macchiatto

b/g by far, then g/g.

(Since possible combos are:

BG

BB

GB

GG

So half of the possible combos are boy-girl and roughly 1/4 are GG and 1/4 (but like you said, the smallest number for whatever reason) are BB.

BelleBaby

macchiatto:

b/g by far, then g/g.

(Since possible combos are:

BG

BB

GB

GG

So half of the possible combos are boy-girl and roughly 1/4 are GG and 1/4 (but like you said, the smallest number for whatever reason) are BB.

My RE said that B/B twins are less likely to survive early pregnancy, for whatever reason.  Funny, because that's what you and I both ended up with!

omalley

BelleBaby:

macchiatto:

b/g by far, then g/g.

(Since possible combos are:

BG

BB

GB

GG

So half of the possible combos are boy-girl and roughly 1/4 are GG and 1/4 (but like you said, the smallest number for whatever reason) are BB.

My RE said that B/B twins are less likely to survive early pregnancy, for whatever reason.  Funny, because that's what you and I both ended up with!

Me too!  I guess our boys beat the odds!

AgateTimesTwo

I can't find the study--will post a link if I can when I do--but there's a study that seems to show that having a female companion in utero gives a fetus a better chance of survival. Or possibly that having a male companion in utero gives a fetus a worse chance. They're not sure why, but it does seem true that both males and females who gestate with males (not just twins but higher order multiples, too) seem to do more poorly. It would then stand to reason, however, that females who gestate with females should do the best, and therefore a shade MORE than 25% of frat twins should be g/g. But they're not.

Hmmm...

Dude, I wish I could find that study!

Temp159135562506975

white male babies have the worst survival rate - they tend to do the worst when born preemies, etc.... I know that.  they call it "whimpy white male". I was terrified to have preemies b/c of that - thankfully I went to term!

 

macchiatto

AgateTimesTwo:

and therefore a shade MORE than 25% of frat twins should be g/g. But they're not.

Hmmm...

Dude, I wish I could find that study!

Actually, I've read that they are. I forget the exact numbers, but it was a bit over 25% of fraternal twins are GG and a bit under 25% are BB.