Any mathematicians out there? UPDATE

[redhookmom]

If a pregnant woman has three girls what are here chances of having another girl? I know that overall your chances of having a girl are 49% but what are your chances of having a fourth?


She had a BOY!

[candybomiller]

Is this a trick question? You know, like it's a 50/50 chance of having a girl, so no matter how many times you do it, it's still a 50% chance? Or are you asking about having 4 girls in a row? I think my high school math teacher would still say it's a 50% chance based on the relative humidity in the air.

LOL! I'm no mathematician, as you can tell. :)

[redhookmom]

Not a trick question as far as I know! A friend of mine has 3 girls and is pregnant so we were trying to think back to stat class. Somehow we thought it would have to be more "probable" that she would have a boy.

[NEVE and TRISTAN]

Steve is degreed in Statistics and I just asked him (and he and his buddy are still talking aobut it as I type)...but he said he beleives it would be 50% (or 49% based on your info supplied).

Now I am going to throw in my own thoughts that I suspect it could even be higher, for if she has 3 girls I start wondering about the sperm that her mate produces...and so far statistically the longer living slower swimming "female" sperm are the ones having success with their chemistry make up...so my gut feeling is that her chances are higher...but that is based on nothing I learned in school just me doing the "Neve factor" there :)...

I must admit that Steve didn't answer as if it was a no brainer, so I am not certain that he is comfortable with his Stat degree answer :)...
Neve
http://home.nc.rr.com/ourbabytristan
AKA "mama2be"-forgot password
and Baby Boy Tristan born @UNC
Feb 25, 2003
Brother to 3 pups "gees" and 2 kitties

[COElizabeth]

Mathematically speaking, the chances of having 4 girls are low (roughly 6 in 100, if I calculated correctly), but that's in advance of the whole process, before any of them have been conceived. Each individual pregnancy has the same odds of producing a boy or girl as any other pregnancy, though, so her odds of having a boy this time are the same as anyone else's. However, that's assuming that there's nothing biologically different in her case. I suppose that it could be possible that something about her DH's sperm or her environment (mucous, etc.) favors girl conceptions, but otherwise, no, she is no more likely to have a boy this time than anyone else.

Elizabeth, Mom to James, 9-20-02
EDD #2, 10-30-04

[daisymommy]

Well, based upon on my two friends, one of whom has FIVE boys, and one who has FOUR girls, I'd say she has a 100% chance of having another girl!(just kidding...sorta ;))
I agree with Neve, that in most people's case with several children of one ceratin gender, there is probably something going on with a woman's Ph levels in her body or her DH's sperm that tend to create one gender over the other.

[egoldber]

As a statistician :), Elizabeth is correct. Regardless of your history, the chance of any individual pregnancy being a girl is 50%. Even if cases where there are known conditions that influence gender (reduced sperm motility, etc.) the odds are only very slightly influenced.

And my mother was the oldest of EIGHT girls. :)

[candybomiller]

WooHoo! My uneducated guess was (fairly) correct!

Go me, go me. :)

[alleyoop]

He he! Don't ask my Dad! I am the middle of three girls... but I think it runs in the family. This is the order of his siblings:

girl
girl
girl
boy
girl
girl
girl
girl
girl
girl
girl
girl
boy (my dad)

Yes, you read that right! He was the thirteenth child! As the story goes, after the first boy they decided to keep going until they had another boy. Eight girls later... now that is committment!!

[COElizabeth]

LOL! I am sure he was delighted when Nate arrived to ensure the next generation would have at least one boy!

Elizabeth, Mom to James, 9-20-02
EDD #2, 10-30-04

[redhookmom]

Well, I guess she is going to have a girl. What seals the deal is that she has a boy named picked out and no ideas for a girl!!

Thanks for all of your responses I am going to send her this thread. Maybe she will start posting here.

[californiagirl]

All other things being equal, she'd have a 49% chance of having a girl. But all other things are not equal, and according to one of the stats books I have, this is not merely a statistical question but a biological one, and her chance of having a girl is *over* 49%. That is to say, if you count up all births, 49% of them are girls. But if you count up all births to people whose previous child is a girl, more than 49% of them are girls. The more girls you have, the more likely that there's something about you as parents that predisposes you to have girls.

Not to mention, and this is not evidence, my friend with the two girls who took one last try did not have another girl. Nope, she had *twin* girls. (But the friend with two boys got a girl on try 3, even though the same statistical trend applies to boys.)

[JElaineB]

She shouldn't lose hope, if she wants a boy that is. My mom had 3 girls in a row then a boy. She did try for a boy though and all 3 girls were "accidents". Did your friend do anything special to try for a boy, like having sex on the day of ovulation and not before?

Jennifer
mom to Jacob 9/27/02

[AngelaS]

Interesting thread, considering I have two girls and am pregnant again. Everyone tells me I'll have a boy this time and I am NOT convinced! LOL

I come from a family of four girls, my stepmom had 3 girls and then a boy, a friend has 5 girls and another friend had 8 girls before a boy....

[ddmarsh]

Since males determine that sex sometimes it seems like you are able to see patterns by looking at the DH's family. I have a friend whose DH's family has nothing but boys, sometimes it seems like weird patterns like that occur.

[NEVE and TRISTAN]

That's what I thought...
and I assume you are correct in that it is a biological issue vs a stat one...that was my gut feeling on it.

Now you'll have to keep us posted on what she has or what the US shows when she finds out!!!!
Neve
http://home.nc.rr.com/ourbabytristan
AKA "mama2be"-forgot password
and Baby Boy Tristan born @UNC
Feb 25, 2003
Brother to 3 pups "gees" and 2 kitties

[redhookmom]

This is her 4th "accident!!!!!"

[redhookmom]

Well, to complicate things her first DD was from her first marriage. Maybe she is biologically attracted to men who will provide her with girls. (LOL)

[bluej]

LOL! I have a friend who claims that all five of hers are accidents! And they are all girls. Her brother and his wife have four, all girls, but they don't claim all of them as accidents. So hmmm, I wonder if accidents usually end up being girls?

[JElaineB]

That's the theory I have come up with in talking with family and friends. If the conception is an accident, then the baby is more likely to be a girl. If it was planned, it is more likely to be a boy. Because when you are planning you try to have sex right around ovulation, which is supposedly better to get a boy. If it is an "accident" you might have had sex a few days before, which is supposedly better to get a girl.

As a side story, my mom is friends with a woman who is about 6-7 months pregnant. She announced it was a "accident" when she told people she was pregnant. She says she didn't know how it happened. :) My mom thought it was planned (thought that because of a variety of factors) but that her friend didn't want to admit to planning another kid at this point. I told my mom if it was planned it would be a boy, if it was an accident, a girl. Sure enough the US says it is a boy!

Jennifer
mom to Jacob 9/27/02

[urbanmama]

Both of my children were very carefully planned and they are both girls!

[egoldber]

I offer up my sister as a counter example to your theory. :) All 3 of her children were "accidents", conceived while on the pill no less. Two boys and one girl. :) (And one tubal ligation....)

[JElaineB]

Oh I totally agree it is just a wild random hypothesis! :) I'm sure there are plenty of counter examples. It is just based on people I know, which is not a very scientific sampling! :)

Jennifer
mom to Jacob 9/27/02

[pixelprincess]

if all else fails...how about using the Chinese Lunar Chart for gender selection...LOL!!

http://www.thelaboroflove.com/chart/cal.html