The myth: Medically speaking, when a woman experiences orgasm, the uterine contractions caused by the action propel the sperm to quickly move into the cervix. This moves them almost immediately toward the fallopian tubes.
The fact: While an orgasm is not a bad thing and it can in fact, help move the sperm in the egg’s direction, you don’t really need to depend on it. In a study called the Shettles Method of ovulation, it was suggested that both partners must time their climax to conceive a boy.
While it says that you need to increase the frequency of having sex to conceive a girl.
It concluded to say that to conceive a boy, the woman should have an orgasm and to conceive a girl, the woman should not have an orgasm because orgasm increases alkaline secretions in the vaginal tract, which may favour boy sperm.