#shettles-method

Claims have been made that diet can be manipulated to determine the sex of offspring. These claims, in fact, were the subject of a 1982 book called The Preconception Gender Diet by Sally Langendoen, R.N., and William Proctor. Of course, there is nothing new about such claims; the idea that diet can influence gender has been around for centuries. What is new is that this diet theory appears at least to have some scientific underpinning. In short, there may be something to it. But read on before you get too excited.

The new work is based on the research of Dr. Joseph Stolkowski of Paris and Dr. Jacques Lorrain of Montreal. Dr. Stolkowski noted that, in the 1930s, Dr. Curt Herbst of Germany had discovered that the sex of marine worms could be influenced by mineral manipulations. He decided to see if the same thing might be true in higher animal forms, and reported that it was. Diets high in salt, he claimed, resulted in significantly more bulls than heifers. Dr. Lorrain subsequently entered into a collaboration with Dr. Stolkowski, to see if diet could similarly influence human sex ratios.

The first results of this collaboration were reported in the International Journal of Gynaecology and Obstetrics in 1980. The two doctors put 281 women who wanted children of specific sexes on two different diets. The “girl diet” is high in calcium and low in salt and potassium. The “boy diet” is high in salt and potassium and low in calcium and magnesium. Husbands were told to go on the same diets as their wives—mainly in order to lend psychological support and help ensure that the wives didn’t “fall off” the diets. The couples were instructed to stay on the diets for a month to six weeks before attempting to conceive. If they had not conceived within six months, they were told to discontinue the diets. Some 21 women dropped out of the study because they couldn’t tolerate the diets or had negative reactions to them or because they lapsed and became pregnant before they had given the diets an adequate chance. The doctors reported that of the 260 women who stuck with the diets, approximately 80 percent conceived children of the desired sex.

No convincing hypothesis has yet been put forward to explain why this method works, if in fact it does. Researchers have speculated on a number of possible modes of action. Possibly the diets affect the secretions within the female reproductive tract in such a way that, depending on which diet is used, either X or Y sperm are better able to move through those secretions. Or perhaps the manipulation of the minerals in the diets affects the membrane of the egg, making it easier for one or the other type of sperm to penetrate. Perhaps the diets affect the female immune system, selectively favoring one type of sperm over the other, again depending on which diet is used. And possibly the diets affect the sperm cells, too, since the husbands also adhere to the diets.

Before you jump to the conclusion that you can eat your way to the baby of your dreams, be aware that there are some potential problems with the sex-selection method based on these diets. First of all, at this point, the method rests entirely on the work of Stolkowski and Lorrain, who have conducted but one clinical trial, and that trial involved a relatively small number of women. Independent confirmations have yet to materialize. Second, following these diets for even a few months may turn out to be unpleasant and highly inconvenient. Third, there is the possibility of health risk.

All who read The Preconception Gender Diet will note the multiple warnings it contains, cautioning readers to consult their doctors before going on these diets and then, once on them, to continue consulting their doctors. The reasons for this are apparent when you get into the specifics of the diets. The boy diet, in particular, may be risky for some people because it requires a higher salt intake than many doctors think is healthy. The authors also acknowledge that the amounts of calcium permitted by the boy diet “are significantly below what is regarded by most nutritionists to be the minimum daily requirement.” The amount of magnesium permitted is similarly well below generally recommended levels.

The authors of the book argue, however, that those who stay on these diets for no longer than six months “probably” won’t experience any difficulty. The trouble with this kind of reasoning is that it will take only a few isolated instances of illness attributed to these diets to bring the whole approach into disrepute. What worries us is that people who are already endangering their health with too much salt (a problem that is acute in the United States) will go overboard on this diet. It has too high a salt content to begin with. Some, thinking “if this much is a good thing if you want a boy, then more might even be better,” may be tempted to add still more salt to an already salty diet. And some others, who do not become pregnant within six months, will inevitably be tempted to stay on the diet and “keep on trying.” The authors point out that there are some people who shouldn’t use the diets for even a month, given preexisting health problems; but will all those people heed these warnings or recognize that they fall into these at-risk categories?

Among the obvious “contraindications” to the boy diet is hypertension (high blood pressure or even a predisposition to hypertension). Drs. Stolkowski and Lorrain reported that four women who were trying for boys had to drop out of their study because the high salt intake resulted in edema, or water retention, a sign of potentially dangerous circulatory problems. Women on the girl diet have been warned to be on the lookout for kidney problems, too much calcium in their blood, excessive nervousness, and so forth.

Langendoen and Proctor concede that the Shettles method may have validity but argue that it is too complicated and takes too much of the spontaneity out of the sex act. We are willing to bet that the overwhelming majority of people who try both methods will decide the Shettles method is, by far, the easier to follow and is encumbered by neither the health risks nor the day-in-and-day-out hassle of a diet that is bound to become obnoxious to many people.

At the same time, we do not want to criticize this research too harshly. Unlike the Whelan method, which we discussed earlier, this one appears to be based on sound, scientific methodology. It is our hope that with further study the promising work of Drs. Stolkowski and Lorrain will not only be confirmed but will yield information that will allow for the development of dietary alterations less taxing and risky than those currently recommended by Langendoen and Proctor. If those things happen, it will be interesting to see what results might be obtained by combining all or various aspects of the Shettles method with those of a revised dietary method. Some Japanese researchers, in fact, are investigating these possibilities.

Before you begin, make sure that you understand everything related to:

Determining your time of ovulation (using BBT, CM, etc.)

Timing of intercourse relative to the time of ovulation

Rules concerning abstinence and use of condoms

The sperm count factor and frequency of intercourse prior to the “cutoff”

Sexual positioning and male penetration

Withholding of female orgasm

If you have any doubts, reread this chapter and the two preceding ones. You may find answers to other questions in the next chapter.

If you decide to use one of the ovulation-prediction kits to help you plan the timing for the girl, first reread what we had to say about these kits in the last two chapters. And use these guidelines:

First, if your cycles are quite regular, you may feel you have no need to use these kits—and you really need not. If your cycles are fairly unpredictable, however, and/or you want extra assurance that you are timing things properly, then you may want to consider these kits. (We hope that, by the time this new edition of our book appears, some more reasonably priced kits will be on the market. Already there are differences in price, so it does pay to compare products. All of the kits that use monoclonal antibodies are about equally reliable, so far as we can determine.)

It’s best not to start using these kits—given their cost—until you have some idea of when you ovulate. Then start four or five days ahead of that date and see if you are right. Remember that when you pick up the LH surge, you are, in most cases, within a day or a day and a half of ovulating. Many couples trying for a girl have written to ask us if it is all right to continue to have unprotected sex right up until the test indicates the LH surge is under way. Our answer is no—because, as we’ve just stated, having sex right up to the surge could still put you too close to the “boy zone” for comfort. This is particularly true if you test only once a day, since by the time the LH surge is detected by that single test, it may actually have started many hours before—possibly a full day earlier.

It’s okay to test only once a day to try to get additional information during your practice cycles, but if you are really going to rely in any substantial way on these ovulation-prediction tests for your actual attempt to conceive a girl, then we strongly recommend that you use them twice a day. And just as we suggested in the last chapter, we advise that you test between 11 A.M. and 3 P.M. and again between 5 P.M. and 10 P.M. Space the two tests at least eight hours apart for best results.

In the majority of cases it appears that ovulation occurs about thirty hours after the LH surge takes place in the blood. The LH doesn’t show up in the urine for another four to six hours, typically, so even if you detect the surge when it first enters the urine, you’re still a little “after the fact” and only about twenty-four hours from ovulation in many cases. Thus those trying for girls will want to stop having unprotected sex at least a day before detecting the LH surge (while testing twice a day).

When it comes to trying for the girl, these prediction tests can best be used during practice cycles. Using BBT and CM, choose a safe cutoff date and then use the kit for the next few days to see how accurate your choice was. For the most part you’ll have to continue relying on BBT and CM, but these kits may prove useful to some of you. Be advised, however, that if you are experiencing “peak” CM symptoms, you would be at real risk of conceiving a boy no matter what your ovulation-prediction kit might tell you to the contrary.

Recent studies show good correlation among the prediction kits, BBT, and CM—when all are used properly. Still, there are many individual variations—so get as many “opinions” as possible. When in doubt, use our tried-and-true data related to CM and BBT.

If you have particularly irregular cycles and are relying largely on the BBT method, there are two formulas that might help you decide on which day of the cycle you should cease having intercourse. Here are two case histories that will help explain the formulas.

Case 1. Linda: Very Irregular Periods

The periods are very irregular, and she has never ovulated sooner than day 19.

Taking her temperature every morning before she gets out of bed works fine. She always goes from about 97.6 degrees to 98.4 degrees when she ovulates, but one month she ovulated on day 19 and the next on day 25. Her cycle runs anywhere from twenty-eight days to sometimes forty-five. She wonders if there is any hope that she could conceive a girl. She thought perhaps she would have intercourse on day 17 for five or six months and then move on to day 18, 19, and so on, until perhaps she could get pregnant with a girl. She is in no real hurry and would wait four or five years if she knew she could have a girl.

Dr. Shettles suggested that Linda try out two formulas to see which, when applied to her case, would yield the earliest day on which she should cease having intercourse. The first formula is simply to look at the records of four to six cycles (preferably more if you have time and your cycle is highly irregular), take the earliest date on which you ovulated during those cycles, and subtract three days. In other words:

earliest ovulation date – 3 days

Using this formula, Linda would subtract three from nineteen and come up with day 16.

The second formula is to take the number of days in your shortest cycle and subtract fourteen (inasmuch as fourteen days often, but now always, elapse after ovulation before the new menstrual period begins); when you do this, you get the earliest probable ovulation date in any month. Then you subtract three days from that to put you at a time that favors female offspring. The formula is:

number of days in shortest cycle – 14 days – 3 days

In Linda’s case, then, she would subtract fourteen from twenty-eight (the shortest cycle she has noted), which would give her fourteen. From the fourteen she subtracts three to come up with eleven. Using this formula, then, Linda learns that she should have intercourse up to and on day 11 but no later—for her earliest and most cautious attempts to have a girl.

Linda, of course, might only rarely have a cycle as short as twenty-eight days. But since she has no way of knowing in advance, given her great irregularity, and since she is determined to have a girl and has plenty of time to try, Dr. Shettles definitely recommends that she start with a target date of day 11. She and her husband can have frequent intercourse, without a condom, right up to and on day 11. They must have intercourse on day 11 and then abstain thereafter, at least until they know they are in a “safe” period. Even then, given the irregularity of Linda’s cycles, they are probably best advised to use condoms.

Linda should definitely not start with a target date as late as day 17. If after three or four months she fails to conceive at day 11, she can advance to day 12, wait another few months, move on to days 13, 14, 15, and so on, at her own pace. Most women, of course, won’t have these extremely irregular cycles and will not have to put forth this much effort. (And, remember, the CM method may give you valuable additional information that will help you clear up some of the ambiguities, although in extremely irregular cycles the CM pattern may be difficult to interpret.) Even the “Lindas,” we believe, can be successful—if they can be patient and slowly “creep up” on the objective.

Case 2. Mary: far less irregular periods

But after six months of temperature-charting (for one reason or another, she has not wanted to use the CM method), she is convinced that she may ovulate anytime between day 11 and day 15, which is still quite a spread over so short a period of time. The shortest cycle she has recorded is twenty-six days. The earliest ovulation time she has noted is day 11. Given that information, let us again apply both of the formulas and see which will yield the earliest “cutoff” day for intercourse.

Here is the timing strategy for the girl.

You will recall that if the egg is in the fallopian tube or about to descend into it, then intercourse at that time (at or near ovulation) will favor the smaller, faster, male-producing sperm. Therefore, for the girl, Dr. Shettles advises couples to have intercourse four, three, or two days before the suspected day of ovulation. Then, when the egg finally arrives, it is likely that only the sturdier, longer-lived, female-producing sperm will still be “in waiting” and capable of fertilizing the egg.

The idea is to time intercourse well in advance of ovulation, as far in advance as possible (to begin with) but not so far as to completely rule out the chances of conceiving at all. Those who want to be extremely cautious may want to start at the outer limit—four days in advance of ovulation. Generally, however, Dr. Shettles recommends starting at three days in advance of ovulation because at four days, the chances of conceiving are not great. If three days don’t result in pregnancy, you can move to two and a half days and then, finally, to two days. If you have intercourse closer to ovulation than two days, you will place yourself in distinct jeopardy of conceiving a boy.

The first task, as with the boy, is to determine your probable ovulation time. You will find instructions on how to do this in the chapter “First Order of Business: How to Determine the Time of Ovulation,” with some additional pointers in the chapter “Trying for the Boy.” Here are some things to be particularly mindful of in planning for the girl. During your practice cycles it is imperative, of course, that you use some form of birth control. Do not use the Pill, for reasons explained in the last chapter. You shouldn’t use IUDs, either. And though in the past we’ve indicated it was all right to use contraceptive foams or jellies (with diaphragms), we no longer recommend their use.

It is true that pregnancies that occur as a result of the failures of contraceptive foams and the like tend more often to be girls than boys; this is due, Dr. Shettles believes, to the fact that these chemicals are highly acidic and thus tend to kill the male-producing sperm first. The use of these foams and gels, however, will interfere with your important CM readings and will render use of Tes-Tape worthless. You might say, “So what? If I fail while using foam I’ll probably get a girl anyway.” Your reasoning would not be sound. In the first place, your chances of conceiving a child of either sex are greatly diminished while using these substances, and, second, you might, if you did manage to conceive at all, still have a boy.

The best form of birth control to use during your practice cycles is the condom. It will keep the vagina free of seminal fluid, which might be mistaken for cervical mucus and thus give you false CM readings. Use condoms and go through enough cycles to make you feel confident that you can predict when ovulation will occur. Then and only then should you make your first attempt.

Concentrate first on mastering the CM method of finding ovulation time. Keep careful charts and notes. Even if you are not particularly successful in pinning down the exact time of ovulation, chances are excellent that you will be able to distinguish between the various gradations of CM. Avoid intercourse, in particular, on your peak CM day, as that is likely the day of ovulation. If your cycle is fairly regular, you will be able to determine when peak symptoms occur. Intercourse should take place at least two days before the peak. Of course, if after several months of trying you still have not conceived, you may decide to risk moving in a bit closer to the peak. And especially if you have two consecutive peak days, eventually you may decide it is necessary to have intercourse on the day prior to the first of those peak days. Use caution, patience, and common sense.

You should also learn the BBT method of finding your ovulation time. Use this temperature method in conjunction with the CM method. Place your higher trust in what the CM tells you, unless, for some reason, you find it difficult to interpret the CM but discern fairly clear BBT patterns. Then you may decide to rely more heavily on the BBT. But, almost always, the two methods complement one another. Some may want to consider using an ovulation-prediction kit along with CM and BBT. You’ll find instructions on using the kits later in this chapter.

This method has been around since the 1960s, and claims a 75 percent success rate for couples hoping to conceive a girl.

Dr Shettles believed that the most important factor in gender determination, was timing. The baby’s gender is determined by the chromosome carrying sperm.

Boy sperm swim faster, but survive for shorter periods of time than their female producing counterparts.

Girl sperm are stronger and more resilient, yet swim slower than boy sperm.

According to the Shettles method, you should have sex two to four days before ovulation if you are hoping to conceive a girl.

By the time ovulation occurs, only the girl sperm should be left to fertilise the egg. Dr Shettles advises that, if you wish to conceive a girl, you should avoid intercourse when you have clear, egg-yolk like vaginal mucas as this is a sure sign of ovulation. It should be noted, however, that avoiding intercourse during this time can reduce your likelihood of conceiving at all.

1. The Shettles Method Timing

2. Shettles Method for Irregular Cycles

3. Shettles Method Girl: Ovulation Prediction

4. Shettles Method Girl: Checklist