Almost from the beginning of his career as a specialist in obstetrics and gynecology, Dr. Shettles was confronted by parents eager to choose the sex of their children. Up until the early 1960s, Dr. Shettles did not believe there was anything he or anyone else could do to beat Mother Nature’s odds. “It looked like it was going to have to stay roughly fifty-fifty,” he recalls. Still, in part because his patients kept prodding him, he began looking for “anything that might be exploited toward this end, particularly anything related to differences in the two sperm types we then knew existed.”
The two types of sperm, as discussed in the preceding chapter, are the Y-bearing (boy-producing) sperm and the X-bearing (female-producing) sperm. It was known some years ago that the Y chromosome is markedly smaller than the X chromosome. Dr. Shettles hoped that this difference might be expressed in the overall head (nucleus) sizes of the two different types of sperm. This might provide a means of fairly easily identifying and perhaps of separating the two types for use in artificial insemination, and so on. Unfortunately, using standard microscopes and staining techniques, Dr. Shettles failed to discern anything that would visually distinguish the two types of sperm.
But he kept trying different approaches and, “one night,” he recalls, “I decided to examine some living sperm cells under a phase-contrast microscope.” This type of microscope, relatively new at that time, illuminates microscopic objects in startling ways, immersing them in halos of light that sometimes reveal hitherto unseen details. In expert hands, phase-contrast microscopy can produce images of greater depth, images that are closer to reality than those seen under some other microscopes. The phase scope lent an electrifying new dimension to the living sperm, which darted across the field of vision looking a little, Dr. Shettles says, “like electric eels.” He decided he could have a still better look if he could just slow down the sperm somehow. He did this by introducing a small amount of carbon dioxide gas into the fluid through which the sperm were swimming. The gas put the sperm cells into “slow motion.”
“The very moment they slowed down I could see the difference,” Dr. Shettles asserts. “There were two distinct populations. I was so excited that I ran upstairs and grabbed the first lab technician I could find. I had to show somebody what I’d found.”
Dr. Shettles promptly published his findings in the May 21, 1960, issue of the prestigious British journal Nature. On June 5, 1960, this discovery was reported in the New York Times.
Dr. Shettles continued to examine sperm specimens, and his observations continued to hold up. In most specimens he’d find more of the round-headed sperm than the larger, oval-headed type. This finding was in keeping with the established fact that far more boys than girls are conceived (various studies have shown 110 to 170 male conceptions for every 90 to 100 female conceptions) and that for every 100 female births, there are approximately 105 male births.
Occasionally Dr. Shettles would come across a semen specimen that contained sperm of unusual uniformity, being almost all of one or the other type. In cases where these were of the larger, oval shape, Dr. Shettles recalls, “I’d find men who had given birth mainly to girls.” And where the uniformity was of the other type, “I’d find men who had fathered an excessive number of boys.”
Early in his studies, Dr. Shettles encountered a specimen that contained nothing but small, round-headed sperm. The sperm donor, Dr. Shettles discovered, came from a family which, for 256 years, had produced almost nothing but male offspring. During two and a half centuries, only two girls had been born to the men in this family.
Speed Versus Staying Power
From these early studies, Dr. Shettles reached three conclusions that were to be of great importance in the development of his sex-selection theories: (1) the male-producing sperm are smaller and more compact than the female-producing variety of sperm; (2) the male-producing sperm are, therefore, very likely faster than their bulkier, female-producing counterparts; (3) the female-producing sperm, on the other hand, because of their greater bulk, probably have greater staying power.
Even though there is still a dispute over whether it is possible to visually distinguish between the two types of sperm, what is important is that others have confirmed beyond any doubt what Dr. Shettles hypothesized: that the Y-bearing, male-producing sperm are, indeed, smaller and faster than the X-bearing variety. This has been demonstrated by means other than phase-contrast microscopy, as will be discussed in more detail later in this book. Dr. Shettles and some others still believe the differences can be visualized under the phase-contrast scope, given the proper preparation and requisite expertise. But, for all practical purposes, that issue is moot. It has been rendered beside the point by other—more persuasive—confirmations of Dr. Shettles’ conclusions with respect to sperm speed and size.
By 1960 Dr. Shettles had a starting point, a place at which he could begin building his sex-selection theory. It appeared to him, as already noted, that there were far more male-producing sperm than female-producing sperm in the average ejaculate. The numerical advantage of the Y sperm, he reasoned, must be a sort of compensation for their fragility, relative to the huskier X sperm. The male, it seems, starts out life, even at the preconception stage, in a state of “inferiority,” a state that is borne out all through life and is evidenced in the fact that there are far more stillbirths and miscarriages of male children than of female, in the fact that more boys than girls die in infancy, in the fact that women have longer life spans and are more resistant to many types of disease, and so on. It is only by having a numerical advantage at the outset that the male keeps roughly even with the female.
That advantage is taxed, Dr. Shettles hypothesized, from the very beginning—when the sperm are ejaculated into the vagina during intercourse. To test this hypothesis, he placed sperm in transparent tubes filled with cervical and vaginal fluids of varying degrees of acidity and alkalinity, such as naturally exist in the female reproductive tract. He found that when the fluids were most acidic, the larger, oval-shaped sperm were able to survive longer than the smaller, round types. He also found that when the fluids were highly alkaline, it was the male-producing sperm that would most quickly swim to the opposite ends of the tubes, which he likened to “physiological racetracks.” When the secretions were more acidic, the likely “winners” were the female sperm. The acids took a toll on both types, but the toll was heaviest on the more fragile boy sperm.
Now, in the normal course of events, a woman’s secretions tend to become most alkaline as ovulation approaches—nature’s way of enhancing chances for fertilization. As you move away from ovulation in either direction, either before or after, the secretions become more acidic. Experiments showed that the female-producing sperm could not only better withstand the acids, they could also better withstand a number of forms of stress, such as heat, toxic chemicals, and so on.
With this information in hand, it became evident that timing of intercourse relative to the time of ovulation might be the most crucial element in sex selection. Dr. Shettles theorized that intercourse that occurs at or near the time of ovulation will, more likely than not, result in male offspring. This is because the secretions in the reproductive tract of the female are most alkaline at or near ovulation and thus most favorable to the speedy Y sperm. But if the intercourse that results in conception occurs two or three days before ovulation, when the secretions are more acidic, then the chances for female offspring would be enhanced. This is because the hardy X sperm are more likely to survive in the acidic environment during the lengthy wait for the egg. This is where the X sperm’s superior “staying power” comes into play.
Dr. Shettles sifted through the scientific and medical literature to see if he could find further support for his blossoming theory. He found that some past practitioners of sex selection had made observations with respect to acidity and alkalinity. Dr. Felix Unterberger, a German researcher, had, decades earlier, in the 1930s, treated some forms of infertility with baking soda douches. He had noted that a number of his infertile female patients had extremely acidic secretions. He guessed that the acids were adversely affecting the sperm. When the women used the douches containing the alkaline baking soda, the acids were neutralized somewhat, and a number of these women became pregnant. Equally astonishing was the fact that so many boys were born to these women—far more, Dr. Unterberger and others reported, than would have been expected by chance. Some other doctors followed up on the German researcher’s work with similar results.* Even Emperor Hirohito of Japan is said to have employed an alkaline douche in his successful quest for a male heir.
Dr. Shettles found neither truly adequate confirmation nor refutation of Dr. Unterberger’s work in the literature. Unterberger’s theory had enjoyed a brief popularity and then had faded away for lack of rigorous scientific follow-up by other doctors, most of whom seemed to find the notion of alkaline douches beneath their dignity. Nonetheless, the data from the 1930s was intriguing and certainly tended to support Dr. Shettles’ own developing ideas about sex selection. He doubted that alkaline douches alone would produce boys with any great reliability. Timing appeared to him to be a far more important component, but douching might be a potentially useful adjunct to timing.
Dr. Shettles also found numerous references, dating back to the nineteenth century, to the alleged influence female orgasm can exert on sex selection. Some researchers have claimed that when a woman has an orgasm during intercourse and, especially, when she has her orgasm before that of the man, the chances for having a boy are increased. If there was any truth to this persistent claim, Dr. Shettles decided, it might have to do with the fact that female orgasm makes the secretions somewhat more alkaline.
Even the Talmud, compiled centuries ago, notes a connection between female orgasm and the sex of offspring. “The determination of sex takes place at the moment of cohabitation,” the Talmud declares. “When the woman emits her semen before the man [when she has orgasm first], the child will be a boy. Otherwise it will be a girl.” The man, if he wanted a boy, was directed therefore to “hold back” until after his wife had an orgasm.
This was interesting in and of itself, meshing as it did with the reports of researchers in more recent times. But Dr. Shettles found another directive in the Talmud that was equally or even more interesting. Orthodox Jews were instructed not to engage in sexual intercourse during a woman’s “unclean” period, meaning during her menstrual period; nor should they have intercourse for a full week thereafter, declared the Talmud. Orthodox Jewish authorities Dr. Shettles consulted confirmed that many Jewish couples abstain from intercourse for the first two weeks of the cycle; thus the first intercourse of each cycle would occur at or near the time of ovulation for most of these women. Taking this into account and considering the less important but still noteworthy directive on female orgasm (which might be expected to increase alkalinity), Dr. Shettles wondered if he hadn’t found the reason why Orthodox Jews have a disproportionate number of male offspring, as has been reported for decades.
Of still greater importance to Dr. Shettles was the data on artificial insemination. It seemed clear to Dr. Shettles that if his theory was valid, then artificial insemination should produce significantly more boys than girls. The reason for this is that artificial insemination is usually timed to coincide as closely as possible with ovulation, so as to maximize the chances of conception occurring. (Artificial insemination can be costly and somewhat traumatizing to some women; thus doctors try to achieve pregnancy via artificial insemination with as few attempts as possible.) Prior to any artificial insemination, the conscientious doctor does everything he can to pinpoint as closely as possible the woman’s ovulation time.
Dr. Shettles looked at the records of thousands of women who conceived by artificial insemination. He found that about 160 boys were conceived for every 100 girls! Many others have confirmed this fact. Artificial insemination does, indeed, result in a preponderance of male offspring, just as would be predicted by the Shettles theory.
