Sex in age of mechanical
reproduction
BY DAVID F. SALISBURY
"Neither science nor
the humanities has so far adequately prepared us for the
consequences of sex in an age of mechanical
reproduction," writes chemistry Professor Carl
Djerassi in the July 2 issue of the journal Science.
According to Djerassi,
continuous improvements in assisted reproductive
technologies (ART) are causing a gradual separation of
sex and fertilization that is continuing the shift in the
balance of reproductive power in favor of women.
"Detaching the child
from traditional procreation may well be the most
fundamental ethical issue raised by ART," the father
of the birth control pill says.
This process began in the
1970s with the development of in vitro fertilization
(IVF), in which a woman's eggs are removed and exposed to
millions of sperm. Once fertilized, the egg is returned
to the woman's womb.
The IVF procedure now is
taken for granted in the affluent countries of the world,
but another technology, called intracytoplasmic sperm
injection (ICSI), has been developed in the last few
years that has profound but generally unrecognized social
implications, Djerassi says.
ICSI causes fertilization
by directly injecting a single sperm into a human egg.
"Given that the fertilization of a woman's egg
during normal intercourse requires tens of millions of
sperm, and that a man ejaculating even as many as 3
million sperm is still functionally infertile, ICSI is a
powerful tool for the treatment of male
infertility," he writes. In fact, more than 10,000
ICSI babies have been born since 1992.
The new practice is
proving of even greater benefit to older women trying to
conceive. The quality of the eggs of women who postpone
childbearing to their late 30s or early 40s is not what
they were when they were in their 20s. But with ICSI,
women can have their eggs frozen when they are young and
draw on them when they are older and greatly improve
their chances of a normal pregnancy later in life, he
said.
"Of course,
motherhood at an older age is physically, psychologically
and economically suitable only for certain women, but at
least the choice is now available in wealthy
countries," he said.
Once the ability to
separate X- and Y-chromosome-bearing sperm effectively is
developed, then ICSI will give parents control of the sex
of their offspring without abortion. In the case of a
couple with four daughters who want a son, such sex
predetermination would be beneficial. But if practiced
widely in a society that favors sons over daughters, the
result could be serious excesses of young males in future
generations, he says.
On one hand, ICSI makes it
possible to create instant orphans by using the frozen
sperm and egg from a dead couple. On the other hand, it
will allow the woman to use the sperm of a dead man so
that she can have their only child, he suggests.
Some people may consider
the prospect of a 45-year-old woman bearing and raising a
child as "unnatural," Djerassi concedes, but
with the longer lifespan typical of today, such a woman
may well be able to raise a child for much longer than
was true for a 20-year-old mother at the turn of the
century. SR
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