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Authorship: by Roger Hunt -- semi-frequent misc.kids and misc.kids.pregnancy contributor; college professor of geography and planning (*not* of biology, although he did teach a course on population fertility); AND spouse for one wife, dad for two kids, with a 3rd baby on the way (as of this writing!) Whenever you see the "I" "me" "my" references in this FAQ, they usually refer to me, Roger -- except in Section 3.3, of course.

Basically, men produce two types of sperms, the X (female) and Y (male). According to Dr. Shettles' studies the y-sperms are smaller, weaker, but faster than their siblings x-sperms, which are bigger, stronger, but slower.
Based on this fact, there are several things you can do to "favor" the conception of boys or girls:
(1) The most important aspect of all is timing of intercourse during the monthly cycle. The closer to ovulation you have sex, the better the chances to have a boy, because the y-sperms are faster and tend to get to the egg first. If you have sex 3 days or more before ovulation, the better your chances to conceive a girl, because the weaker y-sperms tend to die sooner and the x-sperms will be available in greater quantity whenever the egg is released. On the other hand, having sex from 2 days before ovulation, through a few days after ovulation, is better for conceiving a boy. Around the 2-day point -- 48 hours before ovulation -- seems to be the 50/50 mark.
(2) The pH of the women's tract is also very important. A more acidic environment favors girls, since it will kill the weaker y-sperms first, leaving a greater quantity of x-sperms available to fertilize the egg. On the other hand, a more alkaline environment favors boys. Shettles recommends a douche of water and vinegar (acid) immediately before intercourse to favor a girl; a douche of water and baking soda (alkaline) will help for a boy.

(Don't try this without reading Shettles! You have to dilute the douches properly, according to his formula, or they won't help and might hurt you.)

Note: Some women are naturally very acidic and have a hard time conceiving boys.


(3) Position of intercourse and depth of penetration are important, partly because of pH. The closer to the entrance to the vagina, the more acidic the women's tract is. Also, deep penetration places the sperm closer to the egg, and gives those aggressive boy sperms a head start :-). So, a shallow penetration will favor girls and a deeper will favor boys. Shettles recommends missionary-position for a girl, and rear-entry (dog-style) for a boy.


(4) Women's orgasms can also be important. It also has to do with pH. When a woman has an orgasm, the body releases some kind of substance that makes the environment more alkaline, favoring boys. He recommends no orgasms when trying for girls!


(5) The sperm count is another factor. Obviously, a low sperm count to begin with doesn't favor either sex. But a high sperm count favors boys. Shettles recommends three things:

(a) When trying for a boy, don't have sex for 3- 4 days before you reach the target date a day or two before ovulation! For girls, have sex everyday from day=1 or day=5 ("cleaner" :-)), and stop 3 days before ovulation. (b) Shettles recommends that for boys, the man wear loose underwear only -- that is, men who usually wear briefs or other tight underwear should switch to boxers. The idea is the same as wearing boxers to increase overall fertility -- the testicles need cooler temperatures for sperms to survive, and the Y-sperms, since they are weaker, will be helped more than the X-sperms by this method. However, Shettles does NOT recommend the opposite, that men wear briefs for a girl -- this will just decrease overall fertility. (c) Also, for a girl, the man is supposed to take a hot bath immediately before intercourse. "Room temperature" is fine for a boy. The idea is the same as the briefs versus boxers -- give the X- sperms an advantage.


(6) Finally, in trying for a boy, Shettles recommends a nice cup of caffeinated coffee for the man, right before sex -- he isn't clear on how or why this works, but apparently it gives the Y-sperms a jolt!


Well, these are the big ones. Read the book for other details. If you can determine the time of ovulation and follow the rules presented in his book, Dr. Shettles claims a success rate of 70-75% for girls and 75-80% for boys (better than the normal 50%). As you see, it's not 100%!!!
Also, Shettles recommends a "practice" period of 3-6 months, to make sure the couple has all the techniques down properly.



Many of Shettles' methods are also valid (and scientifically accepted) methods for increasing or decreasing overall fertility. It's beyond the scope of this FAQ to cover all aspects of fertility, but paying attention to the following elements is certainly relevant:

A key to increasing fertility overall is charting time of ovulation during every monthly cycle. The three most common methods for determining ovulation are:

* (1) charting basal body temperature (BBT)
* (2) charting changes in cervical mucus
* (3) using an ovulation test-kit. There are many good resources for obtaining information on all these methods, and on increasing fertility in general.

Regarding sex selection in particular, it is beyond question that having sex very close to the time of ovulation is an important way to increase the overall odds for conception. Other methods that are known to increase odds for conception include: deep penetration at the time of ejaculation; for women, having an orgasm together with or following the man's orgasm; for men, wearing boxers instead of briefs; and for men, avoiding hot baths or hot tubs.


  • As you'll note, all of these also correspond with methods that favor boys, according to Shettles. In fact, he cautions that conceiving a girl may take considerably longer than conceiving a boy, *and* may take longer than conceiving using no techniques at all.


The Point: If you have trouble conceiving in general, or think you might have such trouble, the techniques for choosing a girl baby might not be for you -- unless you're willing to be patient!

[NOTE from Roger: I think my next project will be a FAQ on "low-tech" ways to enhance fertility -- i.e., what you can do at home, before you seek medical advice! This is a frequently- asked-about topic on misc.kids.pregnancy]


Here is the text of my original call:

Please let me hear from you! I (we) would like to know your experience with the following:


1. Did you want to try to get a boy or a girl with any pregnancy, in advance of conception?
2. Did you try any (or all) of the techniques outlined by Dr. Shettles in his book? If so, which ones? Please describe.
3. Did you try any other techniques besides those in the Shettles book?
4. Did you get pregnant as a result? What gender was the fetus or baby (or babies, if multiples)?
5. Did you find that any of Shettles' (or other) methods presented any difficulties for you or your partner? Please describe.
6. Overall, would you say you were satisfied with the whole thing? (Did you get the "outcome" that you wanted?)
7. Any other comments?

And, a few procedural things:

Feel free to e-mail me with your answers. I know some of this is kinda personal, so I promise to anonymize all the responses before I save them for the FAQ (strip out headers, change any names in the body of the text, and all that, per usual FAQ procedure.) You can even send me your e-mail anonymously if you know how to do that.


  • You can also post to either misc.kids or misc.kids.pregnancy, and I'll save any responses I see to this thread on either group. BUT: E-mail is preferable! to help our already high-traffic groups stay manageable in size.



Overall, the experience on misc.kids and misc.kids.pregnancy has tended to be more positive than negative. Overall, the responses to date indicate that around 70 percent of all "tries" or outcomes resulted in a "success -- a baby of the desired gender! This is a small and definitely NON- random sample, and all *could* have been due to chance, of course; nevertheless this unscientific survey seems to indicate that Shettles' claims have some validity.


By far the most commonly used method was the timing of intercourse. Nearly everyone who responded used this method, and most had successful results with it.


The second-most common technique was the position and/or depth of intercourse, which was also successful according to responses -- in fact, the position/depth was the most successful technique of all, proportionally, in obtaining the desired baby!


The other Shettles techniques were tried less than five times, so generalizations have to be more cautious. However, all three techniques produced more successful than unsuccessful outcomes.

Here are some summary statistics:

  21        =    Total individuals responses to date26        =    Total "outcomes" -- i.e., total of all               conceptions by those who tried any of               the Shettles techniques, or any other               sex-selection technique(s)NOTE: Some folks who responded hadn't tried Shettles; some tried Shettles multiple times; and some reported friends' Shettles tries! Therefore, all the statistics below are based on number of outcomes, not number of people.

21+ 5     =    Number of outcomes that were successful 

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