Is it true some couples can only have either all male or all female DC?

[maybemumm]

My friend is pregnant and her DP has two daughters from another relationship. She said the baby would be a girl because her DP only makes girls, and it’s just confirmed to be a girl.

Is it true that some couples (men, in particular, as I know it’s men who influence it) can only biologically make either female or male offspring?

As far as I’m aware, there’s no scientific evidence for the theory that some women are only able to carry one sex of baby to term.
There is evidence that some men may produce x & y sperm in differing ratios to 50/50, so there may be a disposition towards one sex over another.

I think it might be possible for some as yet unknown reason.
It's also true that whatever sec your first baby is, there's a slightly higher chance your second will be the same sex. So it's not a definite 50/50 each time.

Yes people might have 8 boys/girls in a row but if you look at people like Michelle Duggar (19 children as well as a stillborn) she has lots of one sex in a row then lots of the other. So if she'd only had the 6 boys in a row, people would say she only has boys, but the daughters either side disprove this. Are there any examples of people with 12+ kids (not unheard of pre-contraception) with all children being the same sex? It seems unlikely.

No it isn't.

There are a few chromosome disorders, normally associated with boys where if the foetus is effected by it then it is likely to miscarry. It's unusual, but very occasionally it could be that. We're talking about minuscule numbers.
I think in basic genetics too, that it would have to be the mother being a carrier for the condition which meant boys spontaneously miscarried. Because if the dad had the condition, then he wouldn't be there.

If you have 3 children then the options you have are:
BBB
BBG
BGB
BGG
GGG
GGB
GBG
GBB

So 8 different combinations, 2 of which are all the same. Which means 1/4, or 25% of all families who have 3 dc, will have all the same. So, whereas it could be potentially true, the majority of times it would not be.

The first time I heard this theory, I thought it bullshit too, both mathematically and scientifically. Each sperm is 50:50 chance of being x or y. But this suggests otherwise…
https://www.sciencedaily.com/releases/2008/12/081211121835.htm

Assuming it’s not fake, it’s actual research from a university, rather than anecdotes and theories. Someone mentioned it earlier on the thread too, the returning fathers effect.

My mum just had 3 girls, I had 2 girls, sister had 3 girls, my daughter had 1 girl.
9 girls and not a boy in 3 generations. Science says just luck, but I wonder if later generations will find reasons. We don’t know what we don’t know

onlyfunfacts.com/history/war/the-returning-soldier-effect/
This is v interesting and explains about how WHEN you have sex can determine gender

Pretty sure there's millions of each type of sperm and one just happens to get through. Flipping a coin could land on tales 20 times in a row, it's rare but it would happen if you got people all around the world to flip a coin.
Sadly I think it really is just 50/50

I've known women who had both sex children but in early infancy the children of one sex died.

so yes, if there are genetic dispositions/disease that are sex specific that might explain it.

This is either a big coincidence or we have the same friend! Were the last 2 twins?

I think some of the posters are potentially being a bit simplistic about this 50/50 chance. At root, that's right but I'd be interested to hear from a reproductive biologist about factors such as temperature, acidity, stress, distance from vagina to womb acne environment generally that might influence which sperm is more likely to survive to reach the egg and which more likely to break through (I gather that its not just a case of "first there wins").

I don't know enough to comment but I suspect there are lots of very interesting factors that could skew the outcome one way or another in various people (or in different environments/ times of life). Fascinating topic!

My ExH (father to my DCs) had 3 older brothers. All the brothers only had male children (5 between them).

When we got engaged to be married his family warned me I'd only ever have boys. I had 2 boys.

Anecdotal obviously but true nevertheless.

Your uterus sounds very prescient.
😂

Thanks for this! So interesting.

There haven't been girls born in our family (following the male line down) for generations - at least 250 years.

Sort of - those mega families like the radfords have a roughly even split, I think.

Robert Thompson (one of James Bulger’s killers) was one of eight boys, no girls.

Yes I was warned too as my dh's family was very male dominated and told not to expect any girls

I have 2 and a ds😀

Aaah that's lovely. I shall keep that in mind if and when my DSs start their own families as I've always assumed if I was lucky enough to have grandchildren they'd probably be boys but obviously there is still hope... 🙂

My MIL only had boys, and apparently she couldn't carry girls. Her step son only had girls and his wife couldn't carry boys.

Honestly I just think it's pot luck and you have an equal chance of either, that it was all just a coincidence that they only had one sex.

Thanks

Also have a dgd.

There are a balance of male/females in my family so maybe that has a bearing

www.bbc.com/future/article/20161014-why-billionaires-have-more-sons

This was an interesting article

I have all girls, I’ve also had unexplained recurrent miscarriages. It does lead you to wonder if maybe there is a chromosomal anomaly only affecting males that means they aren’t viable pregnancies for us!

I find this so fascinating and I think it's a subject which we still don't know that much about.

This article is really interesting....suggesting that the egg can "choose" which sperm it allows to fertilise it. This could explain why sometimes a woman can't get pregnant with one partner, but then becomes pregnant easily with a new partner. Maybe some women have eggs which are more likely to choose an X/Y sperm...?

https://www.manchester.ac.uk/discover/news/human-eggs-prefer-some-mens-sperm-over-others-research-shows/

me & my partner have been together 10 years.. Currently on my 8th pregnancy, and have experienced in order the following... 3 boys, 3 recurrent miscarriages, then our rainbow - 4th boy who was born last year in November, and currently 26weeks with our 1 shot wonder 😂 which happens to be our FIRST girl! So for me @maybemumm I'd just say it's 50/50 either way like flipping a coin, it's got to either land on 'heads' or 'tails'.. Goes to show though, the sonographer who scanned me last year that made a comment referring to the fact "you may not be able to carry a girl" clearly was wrong, unprofessional and just shouldn't of said it! It's down to the man I believe as his swimmer is either an X or Y chromosone as we always carry the X chromosome 😀

My paternal gran had BBBBGGGGG. If she had stopped after 4 you could have said she could only have boys.

My mum had BBBGG, her mum GGGBG.

Large families are less common now so it is likely more smaller families only have children that are the same sex.