Throughout history, people have attempted to influence the
gender of their unborn offspring by following varied and sometimes bizarre
procedures. In medieval Europe, prospective parents would place a hammer under
the bed to help them conceive a boy, or a pair of scissors to conceive a girl.
Other practices were based on the ancient belief that semen from the right
testicle created male offspring and that from the left testicle created
females. As late as the eighteenth century, European men might tie off or
remove their left testicle to increase the chances of getting a male heir.
In some cultures, efforts to control the sex of offspring
has had a darker outcome— female infanticide. In ancient Greece, the murder of
female infants was so common that the male:female ratio in some areas
approached 4:1. In some parts of rural India, hundreds of families admitted to
female infanticide as late as the 1990s. In 1997, the World Health Organisation
reported population data showing that about 50 million women were “missing” in
China, likely because of selective abortion of female fetuses and
institutionalized neglect of female children.
In recent times, sex-specific abortion has replaced much of
the traditional female infanticide. For a fee, some companies offer amniocentesis
and ultrasound tests for prenatal sex determination. Studies in India estimate
that hundreds of thousands of fetuses are aborted each year because they are
female. As a result of sex-selective abortion, the female:male ratio in India
was 927:1000 in 1991. In some northern states, the ratio was as low as
600:1000.
In Western industrial countries, new genetics and
reproductive technologies offer parents ways to select their children’s gender
prior to implantation of the embryo in the uterus—called preimplantation gender
selection (PGS). Following in vitro fertilization, embryos are biopsied and
assessed for gender. Only sex- selected embryos are then implanted. The
simplest method involves separating X and Y chromosome-bearing spermatozoa
based on their DNA content. Because of the difference in size of the X and Y
chromosomes, X-bearing sperm contain 2.8 to 3.0 percent more DNA than Y-bearing
sperm. Sperm samples are treated with a fluorescent DNA stain, then passed
through a laser beam in a Fluorescence-Activated Cell Sorter (FACS) machine
that separates the sperm into two fractions based on the intensity of their
DNA-fluorescence. The sorted sperm are then used for standard intrauterine
insemination.
The emerging PGS methods raise a number of legal and ethical
issues. Some people feel that prospective parents have the legal right to use
sex-selection techniques as part of their fundamental procreative liberty.
Proponents state that PGS will reduce the suffering of many families. For
example, people at risk for transmitting X-linked diseases such as hemophilia
or Duchenne muscular dystrophy can now enhance their chance of conceiving a
female child, who will not express the disease.
The majority of people who undertake PGS, however, do so for
nonmedical reasons—to “balance” their families. A possible argument in favor of
this use is that the ability to intentionally select the sex of an offspring
may reduce overpopulation and economic burdens for families who would
repeatedly reproduce to get the desired gender. By the same token, PGS may
reduce the number of abortions. It is also possible that PGS may increase the
happiness of both parents and children, as the children would be more “wanted.”
On the other hand, some argue that PGS serves neither the
individual nor the common good. They argue that PGS is inherently sexist,
having its basis in the idea that one sex is superior to the other, and leads
to an increase in linking a child’s worth to gender. Other critics fear that
social approval of PGS will open the door to other genetic manipulations of
children’s characteristics. It is difficult to predict the full effects that PGS
will bring to the world. But the gender-selection genie is now out of the
bottle and is unwilling to return.
Investigate the references and links below to help you
understand some of the issues that surround the topic of gender selection.
Answer the following questions:
1. What do you think are valid arguments for and against the
use of PGS?
2. A generally accepted moral and legal concept is that of
reproductive autonomy—the freedom to make individual reproductive decisions
without external interference. Are there circumstances under which reproductive
autonomy should be restricted?
3. What do you think are the reasons that some societies
practice female infanticide and prefer the birth of male children?
4. If safe and efficient methods of PGS were available to
you, do you think that you would use them to help you with family planning?
Under what circumstances might you use them?
References for further reading:
The above questions, and others, are explored in a series of
articles in the American Journal of Bioethics, Volume 1 (2001). See the article
by J. A. Robertson on pages 2–9, for a summary of the moral and legal issues
surrounding PGS.
“ Gendercide Watch” Web site http://www.gendercide.org/
The Genetics and IVF Institute (Fairfax, Virginia) is
presently using PGS techniques based on sperm sorting, in an FDA-approved
clinical trial. As of 2008, over 1000 human pregnancies have resulted, with an
approximately 80 percent success rate. Read about these methods on their Web
site: http://www.microsort.com/
Adopted from: Concepts of Genetics 11th edition by Klug, Cummings, Spencer, Palladino p.193
