Choosing the sex of a baby before it is born
I have two girl babies. But I wish a boy. Can medical science help me
to born a boy baby? Saima, Lahore, Pakistan
None of the
easy procedures that we have developed to influence the sex of the new born
has been proved to work, according to the rigorous standards of medical
journals. But because they haven't been proved effective, doesn't mean
they don't actually help.
If you want to try, here are some tips on how and when to have sex so it
favors a boy-child, according to Dr. Shettles, who wrote a book on the subject
(How
to Choose the Sex of Your Baby) and researched sperm characteristics
in the 1960's.
Men produce two types of sperm: y-sperms that determine the baby will be
a boy and x-sperms for a girl. Dr. Shettles noted y-sperms are smaller (verified
recently) and perhaps
faster and weaker than x-sperms. So, he recommended these practices to
give the boy-producing y-sperms their greatest chance to succeed in
fertilizing the egg:
- The most important thing is timing of intercourse in the woman's monthly
cycle. Since the y-sperms are fast, have sex close to when the woman
releases the ripe egg (ovulation). Two days before ovulation through a
few days after ovulation work best. The fast y-sperms can then beat
the slower x-sperms to the egg, and you end up, maybe, with a boy baby.
- Since the y-sperms are weaker, you need to help them reach the egg by
releasing them as close to the egg as possible. Deep penetration and
rear-entry (doggy style) helps.
- The environment in the woman's womb makes a difference. The more
acid it is, the more likely it will kill the weaker y-sperms. A woman
can help make her womb less acidic by having an orgasm.
"It's difficult to put too much faith in this type of folk-lore stuff,"
cautions Michael
Tucker, scientific director of Georgia Reproductive Specialists.
Y-bearing sperm are a little smaller and, therefore, lighter. But
whether this truly translates to being faster and weaker is "a little
dubious to me!"
"This topic is obviously an ethical minefield," says
Gail Sullivan, retired assistant research professor of medicine at the
University of Virginia Health Science Center. She, however, calls our
attention to another "interesting (and expensive)" method of sorting x- and
y-sperms by the amount of DNA the sperms carry.
Biologist Glenn Welch operates the Beltsville high-speed sorter that
separates X and Y sperm. Photo courtesy of the USDA.
The female-producing x-sperm contains more DNA than the male-producing
y-sperm. Researchers use a fluorescent dye to stain sperm in semen; the
dye binds to sperm according to the amount of DNA it carries. They shine
a laser beam on the sperm, and separate the brighter glowing x-sperms from the
dimmer y-sperms.
The procedure (called
MicroSort) costs about $6000, but shifts the 50:50 x- to y-sperm ratio in
semen to 90% x or 75% y. Then parents can choose the sorted semen they
desire for insemination, and thereby achieve family balancing. It's not
perfect, but in the 1,000 pregnancies and 900 births so far (January 2006) 91
percent of parents who wanted girls succeeded, and 76 percent of those who
wanted boys succeeded. MicroSorting can also reduce the likelihood of
having children with x-linked disease.
Further Reading
Scientific aspects of preconception gender selection, Reproductive
Biomedicine Online. 10 Suppl 1:111-5, 2005 Mar.
Choosing your baby's
sex FAQ
(Answered Jan. 10, 2008)
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