The Center for Fertility and Gynecology

Selecting the Sex of Your Baby

Jul 20, 2012 @ 09:50 AM — by
Tagged with: Ivf Pgd Gender Selection

Many couples in the USA and worldwide are coming to the Center for Fertility and Gynecology in Los Angeles for gender selection.  There are various reasons for which couples or a single parent desire gender selection. Often the couple has one or two offspring of the same gender and would like to have a child of the opposite gender. Other times the couple or single parent has no children but have a desire to have a specific gender. There are also rare situations in which a parent desires a specific gender to avoid a specific genetic mutation that can be transmitted only to a male or a female offspring.

While there are many different methods for gender selection, only a few of those are proven to be scientifically valid and are able to realistically guarantee or increase the chances of obtaining the desired gender.

Despite their popularity and publicity, none of these methods were ever proven to be effective. Some of these methods are considered a pure scam

a). Sperm spinning methods: sperm spinning methods for gender selection rely on the fact that:

       1. Sperm containing the Y chromosome is lighter than the sperm containing the X chromosome.

2. Sperm containing the Y chromosome in theory swim faster than the sperm containing the X chromosome.

For “sperm spinning”, the sperm is collected in the laboratory or at home. The sperm is then placed in a solution with different gradient of density in order to separate the “faster swimmer” from the “slower swimmer” and then centrifuges at different velocity.  Unfortunately none of these spinning methods were ever shown to separate “male sperm” from “female sperm” efficiently. In fact when the sperm was evaluated with more sophisticated methods for the  X and Y chromosomes, it was found to have 50% “male” and 50%”female” regardless of the spinning methods used.

b). The Ericsson methods: this method has been pioneered and patented by Dr. Ronald Ericsson since 1970.  The method according to Dr. Ericsson is efficient ~ 80% for boys and about 75% for girls. Unfortunately many researchers that attempted to replicate the Ericsson method did not achieve the same results. With the Ericsson method, the sperm is placed on increasingly thicker layers of Albumin. Sperms containing the Y chromosome are lighter and can in theory swim faster through the column of Albumin compared to the sperm containing the X chromosome. When the Ericsson method is used for gender selection for girls a medicine called “Chlomiphen citrate” is also added. 

Once the sperm is separated it used for Intrauterine insemination.

Many studies that looked into the Ericsson method found very disappointing results. In fact most fertility specialists would not recommend this method as a safe and efficient method for gender selection.

The only two methods that are clinically proven for gender selection are:

  1. Microsort sperm sorting.
  2. Pre implantation Genetic diagnosis (PGD).
  3. The Microsort method is about 90% efficient for conceiving a girl and about 76% efficient in conceiving a boy. The method of separation of the sperm relies on the fact that the X chromosome has more genetic material then the Y chromosome and because of that is slightly heavier. The separation is based on “flow cytometry” in which the sperm is stained with a special fluorescent dye that attach to the genetic material. Since the sperm containing the X chromosome has more genetic material then the sperm containing the Y chromosome, it will contain more fluorescent dye. The sperm is then passed through a laser beam that can cause the fluorescent dye to glow. Sperm that contains X chromosome glow more and is separated for the sperm containing Y chromosome. The sperm is then used either via intrauterine insemination or In Vitro Fertilization.

The two major limitations of the Micorsort methods:

  1. It is not 100% accurate in guaranteeing a specific gender.
  2. It has not been approved by the FDA and is thus not available In the USA.

Pre implantation Genetic Diagnosis – PGD

It is the only gender selection method that can guarantee a 100% accuracy in selecting the desired gender. The PGD process is similar to In Vitro Fertilization –Women receive medication to grow eggs. The eggs are then retrieved transvaginally and inseminated with the desired sperm. The resulting embryos grow in the laboratory for 3 days. On day 3,  a single cell called “blastomere” is then removed from each embryo and sent to be checked for the gender. The embryo with the desired gender is then transferred back to the uterus. An additional advantage of PGD is the ability to check the genetic material of the embryo in addition to the gender and thus distinguish between a “genetically healthy” and a “genetically unhealthy” embryo.

PGD is the only method that is accurate and can truly guarantee a specific gender.