Ericsson Method for gender selection was patented in the 1970s by Ronald Ericsson, Ph.D., of Gametrics, Ltd. This gender selection technique is based on the idea that Y-bearing (boy-producing) sperm are lighter and swim faster than the X-bearing (female-producing) sperm. The Ericsson Method sets out to separate the lighter, faster-swimming boy-producing sperm from the heavier, slower girl-producing sperm.
The Ericsson Method is used with intracervical or intrauterine insemination (IUI). The man’s semen is placed in a test tube on top of a sticky protein liquid called albumin. The more dense layers of albumin are at the bottom of the test tube, and the less dense layers are at the top.
The tube is placed in a centrifuge and spun in order to separate the heavier X-bearing sperm from the lighter Y-bearing sperm. The X-bearing sperm mostly end up at the bottom of the tube, while the sperm from the upper part of the tube would be mostly Y-bearing. The women would then be inseminated with the male-producing or the female-producing sperm. To achieve a girl, the woman may have intracervical insemination and take the fertility drug clomiphene citrate (Clomid) in order to change the cervical mucus. To achieve a boy, the woman may have IUI.
Proponents of the Ericsson method claim success rates of 78 percent to 85 percent for conceiving boys and a 73 percent to 75 percent success rate for conceiving girls. However, many fertility experts say the method has not been clinically proven to increase a couple’s chances of having the gender they desire.
Another sperm-separation method, called MicroSort®, dyes sperm with a fluorescent label and passes them through the beam of a laser. MicroSort® has been clinically proven to be effective; however, it did not receive approval from the Food and Drug Administration (FDA). As of March 2012, the technique is no longer available in the United States.
Currently, the only truly effective method of gender selection thati s endorsed by fertility experts is in vitro fertilization (IVF) with preimplantation genetic screening (PGS).