It is the male that determines the sex of the child.
We used to think that, but I read on FR that studies have shown that the pH level of the vagina determines whether the egg is fertilized by a sperm carrying an X or a Y chromosome. Therefore, it is the woman's duty to make sure her vagina is at the correct pH to conceive a son. If she doesn't, it a sure sign that she's a male-hating feminist.
It must be true, I read it on FR.