more likely to have a girl after a girl and vice versa?

[sillysillysally]

Someone told me that if you have a boy, you're statistically more likely to have another boy (and vice versa.) I was aware that more boys are born than girls (51 to 49??) but didn't know about this statistic and find it fascinating (as mum to a boy and second one due in 7 weeks!)
Anyone heard of this and know what the likelihood is?

i thought it was all to do with which sperm hit the egg first?

if it helps i am eldest of 10, 6 boys 4 girls. the pattern was

G B B G B G B G B B.

I don't think there's any particular scientific trend for this, I think its just a case of nature and what the sperm and egg do at first!?

I had heard this, and I did loads of internet surfing when I was pregnant a second time. In the end had dd first and ds second..

Have heard this theory but don't know if it's true. For what it's worth I had
G G B G
The boy was the only one that was planned, which might mean something - don't know.

Utter crap. Scientific evidence suggests that the odds of having a boy in any pregnancy are 50%.

The chances of your first baby being a boy are 50% (52% I think if you want to get poicky)
The chances of your second being a boy are 50%
...
...
...
The chances of your 10th being a boy are 50%

There is one small thing that some believe affects this - and that is the level of penetration dueing concetpion can affect it. (I think shallower penetration at time of ejaculation gives a statistically higher chance of having a girl as they are stronger swimmers!!!). On this basis you might be majginally more likely to conceive the same sex next time due if you are using the same 'technique'. But TBH the effects are negligible for 99% of the population

Oh, forgot to say (d'oh!), I've had a boy then a girl and I'm now having another girl...

Sorry - you could read my post and think that because I did lots of internet surfing whilst pregnant I had a boy.

Obviously this is not the case.

What I meant to say is that I did lots of research on it and couldn't find anything particularly conclusive on it....

There was a thread recently asking for circumstantial evidence of this.

According to MN genetics experts, unless there is some special family tendency causing lots of babies of the same sex, you have a 50/50 chance each time.

HTH

Yes WW - that was my 1%

A quick trawl of the playground brings up:

BBBB
GGGG
BBB
BBB
GG
GG
BG
BB
BB
BGG
BB
BB
BGBGB
BBB
GG
BGG
GB

Less girls, because as mum of two BB I tend to know the boys families better than the mums. But yes from anecdoctal evidence I would say yes.

iv got 2 girls and expecting no3 most people i know have had 2 the same sex then the 3rd is the other sex which im hoping i have a boy but not thats bothered as long as its healty

It wasn't the penetration thing though, SMS - it was more to do with a tendency to produce more X chromosomes or whatever the difference is. IIRC it was soupdragon (or whatever she's called these days) who knew the details.

I've heard this too and it seemed to be the case for me until... I had bbgggb

(I know loads of families with 4 kids and none of them are all the same. There are quite a few 3s all the same though)

(I have GGBB btw)

I think some men have a high proportion of X or Y sperm. Saw a programme about a couple with loads of boys and they were told that they would be unlikely to have a girl because the guys sperm was 90% Y.

My understanding of it is that once you have already had 2 the same sex in sequence than the odds of you having more of that sex increase. I assume this is to do with the sperm/egg and your individual tendencies/sex drive around ovulation etc etc etc

I was told by a friend who had researched this that by the time we had 3 girls it was 80% likely that the 4th would be a girl (it was) and with each subsequent conception then the likelyhood of it being another girl would increase by 5% but obviously never to 100% I assume?

I dont know but I had
B G G

oh and my mum had GGG
Friend had GBG

By the 1% - I was kind of capturing all possibilities that are the exception to the 50/50 rule

Theories include
Families were the majority of viable sperm are X or Y
Families where the uterus is hostile to one or other sex sperm/fertilised eggs

I think I had read that depth of penetration is the most common cause to skew the results and the former 2 are quite rare and it has only been demonstrated conclusively for a few families worldwide.

Istr some evidence that men are more likely to father girls as they get older. (Or was it boys??? ) Maybe that's where the idea comes from?

Hmm - which was it then, suedonim (we have opposites )

this paper disagrees with that. They find that the number of X=Y from 20 to 60years (200,000 sperm surveyed).

They do however find that the probablity if XY, XX, YY and XXY sperm increases with age (i.e. abnormal)

i thought someone told me once it has something to do with what siblings you have and a scientific survey i read said that 'assertive' women have higher levels of testosterone and aretherefor more likely to have boys?!

dh is one of 2 boys and i am one of three with 2 brothers.

we have 2 boys.

i am willing to have 2 more in my mission for a daughter but will be happy if i have 4 boys to look after me!

John Humphrys and John Simpson - both elderly dads - have boy babies. FWIW