Do Any Preconception Sex Selection Methods Work?

There is a lot of information on the internet about different ways to improve your chances of having a girl or boy baby. Do any of these preconception sex selection methods actually work?

Here is the short answer: Except for flow cytometric sperm sorting, there is no pre-conception sex selection method that has been shown to improve the chances of conceiving a baby girl or baby boy. Methods such as "sperm spinning", density gradient separation, dietary modifications, tying off a testicle, abstinence, timing of intercourse, intercourse positions, ancient Chinese lunar calendars, and altering the vaginal pH are just plain ineffective. Claims made by promoters of these pseudoscientific methods are not supported by sound data, are not independently repeatable, and cannot withstand scientific peer review. None of these other methods have been reviewed by the FDA.

After conception takes place, PGD may be used to identify male or female embryos for transfer in an IVF or ICSI cycle. PGD is a very effective post-conception method of sex selection. Before conception, however, there is only one way to make a girl baby: make sure a sperm carrying an X chromosome fertilizes the egg. To make a boy baby, a sperm carrying a Y-chromosome must fertilize the egg. To increase your chances of conceiving a girl baby or boy baby, the percentage of X- or Y-bearing sperm available for fertilization must be skewed away from the normal 50:50 so that a meaningfully increased percentage of the sperm are carrying the desired sex chromosome (X or Y). The only way to meaningfully increase the percentage of X- or Y-bearing sperm is by flow cytometric sorting of the sperm using MicroSort®. The other methods mentioned above are fine ways to spend time and money to achieve an outcome that would have occurred anyway: a 50:50 chance of conceiving a girl or a boy.