Shettles Method

One of the more popular theories in sex selection, the Shettles Method theorizes that X and Y chromosome carrying sperm have different properties. Y chromosome carrying sperm is considered to be smaller and faster than its X chromosome carrying counterpart. While quicker, Y-carrying sperm is much less resilient to the acidic secretions of the vagina and will die off much quicker. If attempting to have a boy through the shuttles method, intercourse should coincide with the beginning of ovulation. Additionally, rear entry lovemaking is recommended as penetration is deeper and deposits sperm closer to the cervix and avoiding the acidic vagina. If the female has an orgasm, cervical alkalinity is increased as well as the likelihood of the Y chromosome sperm surviving.

On the contrary, if a girl is desired the couple should plan intercourse no later than two days before ovulation begins. This is to allow the less resilient Y-carrying sperm to die off and the tougher X-carrying sperm to reach the egg by the time it ripens. Frontal and less deep penetration such as the missionary position is recommended to expose sperm to the more acidic part of the vagina. Female orgasm should not occur until after the male has ejaculated in order to reduce alkalinity.

Sperm Sorting

Sperm sorting is a process that uses centrifugation (or controlled spinning) in order to sort sperm based on its density. Lighter Y-carrying sperm and denser X-carrying sperm are separated from one another in order to improve the odds of conceiving the desired sex. While there is no way to separate the two types of sperm completely, Sperm sorting typically has a success rate of 78-85% for couples seeking a boy and 73-75% for couples desiring a girl. This method can be done either in vitro or through artificial insemination. Typically sperm sorting can range in price from $1300-$2500 per cycle.

In Vitro Fertilization with Preimplantation Genetic Diagnosis

The PGD technique is really the only method that can come close to absolutely guaranteeing the desired sex of choice. This method must be done in vitro as embryos are tested for sex before being implanted in the womb. It is by far the most accurate technique but also the most expensive which can cost up to $25,000 per cycle. PGD is commonly used for couples that have a family history of genetic disorders or older mothers who are more at risk to have a child with genetic birth defects. Clinics also have very thorough pre-screening processes and will not typically allow couples desiring a particular sex to take part in the procedure.