Sex of gender selection has always been a hot topic. While it is possible for scientists and doctors to identify sperm and select sperm to create a child of a particular sex, this is only done under the strictest controls and for medical reasons. For example, doctors will help couples to have a girl if they know that otherwise a boy would develop a life-threatening condition such as muscular dystrophy.

For couples hoping to have a child of a particular sex, there are some ways in which you can improve on nature's odds, although you may still not beat nature.

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A girl needs two separate X chromosomes