Sibling gender (biological sex at birth)?

[spiritjoe]

@elam84 Some men are more likely to have boys or girls. If your husband/partner has a lot of brothers or a lot of sisters they may be more likely to have daughters or sons. Some men make more y sperm vs X sperm. My husbands mom has 5 brothers and his one uncle has 5 boys but the others had 2 boys 1 girl, or 1 boy 1 girl and 2 girls. Just some men have a higher likelihood of having one over the other but most of the time it’s 50/50 chance each time a child is conceived. It’s like flipping a new coin each time

 

[_ajayy_2014]

@elam84 Eeee!!! Highly recommend reading this book: Do Chocolate Lovers Have Sweeter Babies? The Surprising Science of Pregnancy by Jena Pincott

 

[tgia413]

@elam84 I read somewhere that families who already have more than one of the same sex will often go on to only have that sex. It has something to do with the father's genes. I can't remember exactly where I read it, but I know lots of families that follow this pattern (mine included). I do also know several families where they didn't follow this pattern though, so who knows.

 

[christo617]

@elam84 So, I read a lot of comments that say that your second child is more likely to be the same gender as your first child. I’m wondering how that works if you’ve done IVF to conceive. We did IVF (did not do ICSI for fertilization) and in the first round we got 1 embryo of each sex. In the second round we got 2 female embryos. My husband came from a family that was male heavy and my family is pretty evenly split.

 

[christylb]

@elam84 I'm curious how fraternal twins come into play in any of the research, if it makes any difference at all. As well as miscarriages. If there is a pattern or observable reasoning then it would need to account for such things.

Anecdotally I had fraternal boys (my husband's family is VERY boy heavy). After that I was determined to do everything I could for a girl so I followed all the science that was out at the time as well as all the old wives tales. Sure enough I had a girl. However a friend had two singleton boys and followed all the same advice I did and still got a third boy.

 

[abbayabba]

@elam84 This is an interesting topic! I don't have any studies, but I can tell you about my large extended family. Purely anecdotal, of course.

My dad has 6 siblings, 4 sisters and two brothers. In the following generations, though, boys started to outnumber girls by a longshot. My dad himself had two girls (me and my sister), but three of his four sisters had all boys. The fourth sister had one girl and one boy. One of Dad's brothers also had a boy. So out of 10 of us cousins, 7 boys and 3 girls.

Several of my cousins and I have kids now. There are currently 10 kids (that we know of), including mine, in the next generation. 7 boys and 3 girls. Exact same ratio as my generation so far. Pretty wild stuff!

Another interesting fact: only one of my male cousins has had a daughter. All the rest have sons. The other two girls of the next generation were born to me and my female cousin.

My mom also has a big family, but there's about a 50/50 split of boys and girls in both my generation and the next one on that side.

Outside of my own family, my dad has a friend who has 7 daughters. He and his wife kept trying for a boy and were ultimately unsuccessful, lol.

 

[asdfasdf333]

@abbayabba Wow 7 daughters?! I would’ve stopped after the 3rd

 

[asdfasdf333]

@elam84 I heard the dna from the man determines it ultimately

 

[christylb]

@asdfasdf333 It's not as clear cut as that. A sperm will carry a copy of either the x or the y chromosome from the male (at least for humans). However the environment they enter into, such as the female's temperature levels, can determine which sperm will more likely make it to the egg. I also read an article last year where some believe the egg will be more receptive of some sperm over others, though I don't know how accurate that information is. So while yes the sex of a baby depends on the sperm, there are other factors that determine which sperm make it.

 

[paulrosaly]

@elam84 I read an article (need to find it) that says if you get with a new partner you are more likely to have a child of the opposite gender than with your old partner.

So for example my boyfriend has 3 daughters with the same woman. We had a baby and he was a boy. If we had another baby it would likely be a boy as well. Might not be, but I found it to be true with me.

I’ve seen couples try and try for a different gender and keep getting the same. Had a neighbor that had 3 daughters and finally stopped because he wanted a boy.

I was the first girl in my family in 47 years on one of my parents side. They all had boys.