The sex of the baby is influenced only by the male sperm. There are of course many factors that say to influence the sex of the baby and old wives’ tales about this subject, but none have turned out to be 100% accurate and has not been proven through rigorous methods. If a couple actually desires a boy or a girl mainly, they can follow some methods, as they don’t have anything to lose for that matter. But

A baby’s sex is determined at conception (when the sperm fertilizes the ovum), but at first both female and male embryos develop in exactly the same way and they have identical genital parts until around the eighth week of gestation, when males and females start to develop in different ways. There is an unexpectedly small number or genes that determine the differentiation male/female:  in the nucleus of every cell of our body there are 46 chromosomes, organized