Does the sex of your baby have to do w/ genetics?

Question

I am 21 weeks pregnant, and tomorrow I have an ultrasound. I am so excited. But my boyfriend thinks I am having a boy because of genetics. He has a son, and on his side of the family he has one brother, and his father has 4 brothers and 1 sister.
My side of the family I have one brother, and his first and only child is a girl. My Mom has one sister and one brother. Her sister has a girl. My Dads side of the family he has one brother and 2 sisters, while the brother has a boy and a girl, one of the sisters has a girl, and the other sister has 2 girls and a boy.
Sorry if this is confusing. I just want to know my chances. I will be happy either way, but Im hoping for a girl.
Do you think the sex of your baby has to do with genetics, or not?

Answer 1

The sex of the baby is primarily determined by the man. While any couple has a chance of having either a boy or a girl, the likelyhood of one or another is determined by the characteristics of the man's sperm, which has a genetic component.

Answer 2

There may be certain genetic factors that predispose towards having mostly boys or mostly girls.

THere's a genetic problem called Fragile X. This would result in mostly girls being born as the boys would be at higher risk to be miscarried. It would be carried by the mother, I assume as a the mother has the X chromosome that would be contributed to a boy.

I've heard that the pH balance of the vagina may have an influence on whether a girl or a boy is more likely to be conceived. In fact, some women have tried douches of various pHs to influence the coception of a boy or girl. My grandmother reported conceived 5 boys this way. Perhaps the natural pH of the mother could strongly influence which sperm survived long enough to fertilize the egg.

The proximity of intercourse to ovulation may play a role. Perhaps if a woman has fertile cervical fluid that usually dries up a couple of days before ovulation, she might be more likely to conceive all girls. Likewise, if she only has fertile cervical fluid right before ovulation, she might conceive mostly boys.

I'm quite sure the male has a role other than to just provide the X or Y chromosome. Perhaps the state of his seminal fluid might influece the survival rate of one sperm over the other. Perhaps the male or female sperm might be defective and the other gender might predominat. A man's nutritrional status might influece it as well.

Male embryos (and newborns) are more fragile. I've read that male babies are miscarried more often. Perhaps a family might have a hereditary condition that influenced the survival of one gender over the other...who knows.

It could be coincidence too.

I think it's a lot more complicated than just whether an X or Y sperm happends to reach the egg first. I'd think, though, that when there are problems along the way, female babies would predominate as female sperm tend to be heartier and longer lived and female fetuses/babies are also heartier. I don't know what conditions would necessarily favor boys.

Answer 3

Good luck tomorrow!
Not neccessarily because there are factors in the womb that help but genetically speaking it is the male that determines the sex of the child. There are x and y chromosome sperm and depending on which got to the egg first will determine what the sex of your baby will be. I am the oldest of 7 female cousins with my brother being the only boy on one side of the family. I had twin girls. My husbands brother has 1 girl and 3 boys. So it's totally possible to have either. But one thing to consider is that the Y-chromosomes (male) die more easily in an acidic environent.

Answer 4

the sex of the baby is determined by the Male's sperm. The Chinese believe that when the baby is conceived and the age of the mother at conception has to do with the babies sex. For example a 26 yo woman has more chances to conceive a boy and only few chances to conceive a girl depending on what months she gets pregnant. Where as prior to 26 she has more chances to have a girl and only like a month or two when conceiving a boy is possible. There is not proof to that but it's fun to do anyway.

Answer 5

It has a lot to do with everything. Some men just naturally carry sperm that could be stronger as male or females, that can be due to genetics. Also women can have a more acidic or alkaline vaginal environment which favor one sperm or another. Also a women's diet can affect which sperm is attracted to her egg, boys are attracted to sodium and potassium and girls are attracted to magnesium and calcium. Also timing can determine whether it's a boy or girl. If you had intercourse a couple of days before ovulation, it's more likely to be a girl...and if you did it the day of ovulation, it's more likely to be a boy. There are lots and lots of factors that help determine the sex. But in the end as many will say, it is all up to what sperm is lucky to get there first.

Answer 6

Well it has to do with chromosomes which are composed of genes - so in that respect it's genetic. Your baby either has XX chromosomes - a girl - or XY - a boy and that will be determined randomly. Your boyfriend's theory is wrong regarding being able to predict sex of the baby based on past family patterns of baby gender delivered in the family.

Answer 7

It has everything to do with genetics, but not like your boyfriend says.

You still have exactly a 50/50 chance of having a boy or a girl, just like everyone else. You are not special because of all of the male births on his side of the family.

All men have exactly one X (female) chromosome and one Y (male) chromosome in their genes. They pass down exactly one out of the two of those chromosomes to the child, with a 50/50 chance of the child getting the X or a Y chromosome. If the child gets the X, it will be a girl. If the child gets the Y, it will be a boy.

Answer 8

At the time of conception, it depends on the old X or Y chromosome. Which one your boyfriend provided at that time determines the sex. Family history of all boys or girls does not play a major role in that factor, however, I do believe there is some rhyme and reason to your thinking.....

Answer 9

Actually there have been studies done that have shown that the Y or X sperm in males may be stronger or faster down the hereditary line causing a lot more of one sex in that family line, but it would come from the father's side.

Answer 10

I believe that the sex of your baby is determined by the fathers genes. That does not necessarily mean that you will have a boy. I have heard of families only having boys in their family and still have a girl. Good luck in having a healthy baby whether it is a boy or girl.