Pick a gender, any gender

by Anne Martinez

Pick a gender If you've been reading or watching the news, you've probably heard that parents can now pre-select the gender of babies-to-be. This isn't an entirely new concept. In fact, gender selection has been an issue for as long as people have been having babies. Henry VIII, for example, went through six wives in his quest for a son. Science fiction and history aside, though, there are several ways to influence the gender of the child-to-be.

There are two key reasons that parents want to choose the sex of their baby. The first is the most compelling: prevention of birth defects or genetic diseases that run in a family. Many are sex-linked. For example, if a particular disease is only inherited by boys, then parents can avert the problem entirely by assuring that they have a girl.

The second, more controversial reason is family balance. Parents that already have three sons may yearn for a daughter, others really want their first born to be a boy. In some countries preferences are so strong that infants of the undesired sex are aborted or murdered.

Parents have tried to choose the gender of their children for centuries. An article that appeared in the January 1898 issue of the Journal of the American Medical Association espoused the belief of the time that gender was determined after conception, and could be influenced through the quality of nutrition obtained by each parent (i.e., by what they ate). Now we know that gender is determined at conception, and that what parents do afterward has no effect at all.

Over the years parents have tried to influence the gender of their unborn children by a number of sometimes dubious methods. Some have tried to assume a certain position during intercourse. Others insist on having sex only on particular days, douching, sprinkling salt on the sheets, putting scissors under the pillow, or sorting sperm using the now disproved theory that sperm carrying male genes swim faster. Although none of these methods has proven consistently successful, there are several ways parents can dramatically increase the odds of having a baby of the sex they desire.

These days the focus is on science, specifically various methods for sorting sperm by whether they will produce male or female offspring. The sorted sperm of the desired sex are then used to artificially inseminate the mother-to-be.

MicroSort

The method that's been claiming headlines recently was developed by the Genetics & IVF Institute in Fairfax, Virginia. The MicroSort process is based on the observation that female sperm carry 2.8% more genetic material than male sperm do. To capitalize on this observation, sperm are dyed with a special fluorescent chemical, causing the genetic material within them to glow blue under a laser light.

Dyed female sperm cells emit more light than dyed male sperm cells. A cell-sorting machine is used to separate the brighter (female) from the less bright (male) sperm. The sperm of the desired sex is then used to fertilize the mother. This technique is reputed to produce a child of the desired gender at least 85% of the time for girls and over 90% for boys. The sorting procedure takes most of a day.

Albumin and Sephadex filtration

Another method of sperm sorting called albumin filtration has been used for about 20 years by parents who seek male offspring. In this technique, sperm is passed through glass tubes containing water-soluble proteins called albumin. Only the strongest and fastest-swimming sperm can get through, and those are the ones used to fertilize the mother. This method produces male babies 70%-80% of the time. The procedure takes about four hours.

A similar procedure, called Sephadex column filtration, produces female babies 75%-80% of the time.

In vitro fertilization

The most reliable sex selection procedure currently available is pre-implantation diagnosis using in vitro fertilization (IVF). In this procedure, the mother-to-be is given medication that causes 6-12 eggs to mature in her ovaries. The eggs and the father's sperm are united in a lab container to form embryos. As the embryos begin to develop, they are tested to determine whether they are male or female. Several embryos of the desired gender are then implanted in the mother's uterus. The "extras" are frozen for future use or discarded. In women who do have successful pregnancies, the success rate of the gender selection process is 95%-99%.

Medical ethicists and others are concerned about the ramifications of sex selection techniques. Some experts fear that the dye or the laser used in the MicroSort method may alter DNA in ways that will produce unforeseen effects on the child, or on the child's children. In the IVF method, sex selection takes place after conception, meaning that embryos rather than sperm are being selected or rejected. This takes on almost a "Brave New World" context, about which ethicists are most uncomfortable.

While successful fertilization using the procedures mentioned above dramatically increases the odds of having a child of the desired gender, achieving that fertilization is not an easy process. "One has to take into account the fact that the rate of success with in vitro fertilization is very low," cautions Aliza Kolker, Ph.D., professor of sociology at George Mason University and co-author of the book Prenatal Testing: A Sociological Perspective. "To ignore that fact is a great disservice to parents. At the moment, IVF is used only in cases of extreme infertility when everything else has failed. Anybody that goes into the program knows that the odds of success of actually having a pregnancy and a baby are ridiculously low."

IVF is also extremely expensive, difficult, and traumatic for the woman's body. "She can't go on with her normal life. Couples request IVF for extreme infertility that can't be treated other ways, which is already stressful in and of itself. IVF is a method of last resort for infertility. But to assume that it would be used frivolously for deciding the sex of your baby is totally absurd," Kolker says.

If sex selection becomes wide-spread, there is also a chance it will begin to skew the normal male/female ratio of human beings, with significant consequences. Marriage, family, and sociological patterns could all be affected. For families facing inherited sex-linked diseases, the opportunity to choose the gender of their offspring is a Godsend. But in cultures where sons are considered more superior to daughters, sex selection has graver implications. For all of us, it's a very personal decision, requiring careful consideration of the possible benefits and consequences.