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Deciding Baby's Sex

everyone from your Grandma to the stranger
in your gynecologist's waiting room -- from suggesting a variety of approaches
to influence the sex of your unborn child. The list goes far beyond breakfast
cereal and potassium-rich foods like bananas.

We asked reproductive experts, obstetricians, and those who promote some of
the sex-selection methods to explain and weigh in on the options. 

Breakfast Cereal and Sex Selection

In a study published in the Proceedings of the Royal Society B, 740
newly pregnant British women recalled what they ate the year before conception.
Those who ate breakfast cereals and potassium-rich foods and consumed more
total calories daily delivered more boys compared to those who skipped
breakfast and ate fewer total calories.

It's not certain whether the calories or the nutrients makes the difference,
the researcher says, although the association is one that is seen in other
animals, with well-fed mothers giving birth to males and less well-fed mothers
delivering females.

Among the evolutionary theories as to why girls or boys are conceived is
that parents in good condition favor male offspring or that the
availability of resources and other factors affects the sex ratio. One study,
for instance, shows that underfed hamsters tend to deliver females while
hamsters not restricted on diet do not.

(What do you think about trying to determine
the sex of your baby ? Talk with others on WebMD's
Pregnancy: 1st Trimester message board.)

Low-Tech Methods of Sex Selection

Methods to up the odds of conceiving a boy or a girl are plentiful. If you
search the web for "gender selection" you'll get multiple hits to
articles, a book called How to Choose the Sex of Your Baby, and several
commercial web sites selling gender-preference kits. Many of these approaches
suggest one or more of the following techniques:

  • Timing intercourse closer to ovulation for a boy, further away for a girl.
    The reasoning is that the "girl" sperm (with X chromosomes) are hardier
    and the "boy" sperm (Y chromosomes) are more fragile, so having
    intercourse as close as possible to ovulation will give those Y chromosomes
    that determine maleness a fighting chance of meeting the egg.

  • Making the vaginal environment more hospitable to "girl" or
    "boy" sperm. Some say this can be done by douching with water and
    vinegar to make the environment more acidic and girl-friendly and by douching
    with water and baking soda to make the environment more alkaline and

  • Adopting various positions during intercourse. For instance, the missionary
    position is recommended for producing girls; rear-entry for boys.

But Steven Ory, MD, a reproductive endocrinologist in the Ft. Lauderdale,
Fla., area and past president of the American Society of Reproductive Medicine,
disagrees. "There really is no old-fashioned technique that can influence
sex selection," he tells WebMD.

"Nothing is proven," agrees Richard P. Frieder, MD, a staff
gynecologist at Santa Monica-UCLA & Orthopaedic Hospital in Santa
Monica, Calif.  And finding an association between dietary habits or
intercourse timing or other approaches and having more girl or boy babies is
different than finding a cause and effect, he points out.

"To propose there really is a cause and effect is really on the
fringe," he says of the old-fashioned sex- selection techniques.

His patients who are hoping for one sex over another always ask if there is
anything simple they can do to boost the odds of conceiving a child of the
preferred sex.  "I tell them it's 50-50. The reality is there is
nothing you can do that really matters."

"You have a 50-50 probability of a girl or a boy," Ory says. If a
couple is trying interventions such as dietary changes or different positions
or intecourse timing, he says, "there is a tendency to attribute what you
did to getting results [you wanted]. And people tell their friends. In
medicine, we call them anecdotes."

Proponents of Low-Tech Methods

Combining techniques can give better results, says M. Jericho Banks, PhD, a
partner and owner of Gen Select, a preconception sex selection method sold

By adjusting the body chemistry to be more acidic or more alkaline, he says,
couples can boost the chances of conceiving their preferred sex.

For instance, his company advises those who want a girl to avoid salt and
eat a lot of protein. "It falls in line with the recent study," he

"A lot can help," Banks contends. Making the vaginal environment and
body chemistry "more hospitable" to one or the other type of sperm can
influence conception, he says.

Hazards of Sex Selection?

The dietary changes seem harmless, according to Frieder. But nutritionists
caution women not to skimp on calories or nutrients in the hopes of conceiving
a girl, based on the recent study.

But the method that suggests having intercourse before or after ovulation,
depending on whether a boy or a girl is preferred, may actually reduce the
chances of getting pregnant at all, Frieder says, if couples miscalculate their

In general, the overall chance of getting pregnant each month is fairly low,
he says. "There is a 20% chance of getting pregnant in one menstrual cycle
if the sex is at the perfect ovulation time," Frieder says. If the
intercourse occurs earlier or later, the odds of getting pregnant could
decline, he says.

As for the suggestion to douche, Frieder advises not. "They could be
caustic to the sperm."

But in general, most of the low-tech methods to influence a baby's sex seem
harmless, even if they don't work, Frieder says. "It gives couples
something to do while they are waiting to get pregnant."

Allyson A. Gonzalez, MD, another gynecologist at Santa Monica-UCLA &
Orthopaedic Hospital, agrees. Old wives' tales may deserve respect, she says,
even if they aren't backed by scientific proof. "Old wives tales don't come
from nowhere," she says. If a method won't harm parents-to-be or the unborn
baby, she says, she doesn't discourage it. But she cautions couples not to
count on any of the methods working.

By Kathleen Doheny
Reviewed by Louise Chang
©2005-2008 WebMD, LLC. All rights reserved

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