How Sex Works

by Dr. Sharon Moalem

  There were, however, real problems with some older IUDs. One of the most infamous devices in medical history, the Dalkon Shield, was a plastic IUD made and sold by the A. H. Robins Company in 1971. At the time, the U.S. Food and Drug Administration did not require testing and approval of medical devices in the same way required for pharmaceuticals. A. H. Robins conducted only one test of the product before taking it to market, a year-long trial to examine its efficacy as a contraceptive device that was led by the product’s own inventor. And senior executives of the company were aware of a flaw in the Dalkon Shield’s design that gave it a propensity to “wick” bacteria from the vagina into the uterus.

  Which is exactly what it did—to thousands and thousands of women. “In addition to being responsible for at least eighteen deaths, the Dalkon Shield caused over 200,000 infections, miscarriages, hysterectomies, and other gynecological problems and led to an untold number of birth defects, caused by contact between the device and the developing fetus,” writes Tone.

  A few hundred thousand people filed lawsuits because of problems caused by the Dalkon Shield, resulting in one of the biggest class action lawsuits of all time, with a $2.5 billion settlement. In the category of silver linings, Congress passed a law in 1976 giving the FDA the authority to require testing and approval of medical devices, and President Ford quickly signed it, saying it “eliminate[d] the deficiencies that accorded the FDA ‘horse and buggy’ authority to deal with ‘laser age’ problems.” Thankfully, today’s IUDs don’t seem to suffer from the same problems as their ancestors and are a good contraceptive choice, especially in women who have already had children.

  Another doctor-assisted, maintenance-free contraception is sterilization—but it isn’t really considered reversible, although it can sometimes be reversed through additional surgery. In women, the procedure is called tubal ligation and involves severing, scarring or clipping both Fallopian tubes. In males, the equivalent procedure is called a vasectomy and involves severing the vas deferens, preventing the transit of sperm from the testicles.

  I was first exposed to vasectomies while I was working for the Population and Community Development Association, a Thai NGO. The founder of PDA, Mechai Viravaidya, is widely known as Thailand’s Condom King for his work in making condoms more culturally acceptable. I lived across the street from PDA’s Cabbages and Condoms restaurant, which, besides having an admirable collection of condoms from all over the world, helps provide some financial support for the organization. As part of its mission, PDA also advertised “non-scalpel” vasectomies. The technique is a lot less innovative than it might sound. They used scissors instead, which worked, of course, but it certainly wasn’t the medical miracle “non-scalpel” seemed to promise. Their big innovation was to use a converted Winnebago to perform vasectomies around the country, which they offered for free on Father’s Day.

  When it comes to fame and impact, no other form of contraception can compare to the Pill, or the combined oral contraceptive pill, if you’re being formal. In the combined form the Pill actually delivers derivatives of two steroid hormones, estrogen and a synthetic form of progesterone usually referred to as a progestin. For women who don’t want to remember to have to take a pill every day, there’s a patch that only needs to be changed every three weeks and delivers its hormones through the skin. There are also versions of progestin-only pills, usually called mini-pills, and medroxyprogesterone acetate, sold under the trade name Depo-Provera, an injectable progesterone that works for up to three months a shot.

  The birth control pill has many parents, but the chemical key to its own birth was the development of the first synthetic progestin, norethindrone, which was synthesized by the master chemist, Carl Djerassi, along with a young Mexican chemist named Luis Miramontes in 1951. (I had the honor of meeting met Djerassi just as I was starting college. For an aspiring physician-scientist fascinated by medicine and chemistry, it was a bit like meeting the lead singer of your favorite band.) Djerassi and Miramontes had received an assist a decade earlier when a chemist named Russell Marker found a natural progestin called disogenin in the Mexican wild yam. Before Marker found disogenin, development of the Pill was stymied because all the chemicals being used to develop it were so expensive. Mexican yams, not so much.

  Before we go further in describing the Pill’s creation, it’s worth taking a moment to explore a little-known but somewhat darker side to its development. A year before Djerassi’s breakthrough, birth control advocate Margaret Sanger and philanthropist and women’s rights advocate Katharine McCormick teamed up to encourage the development of a medical contraceptive that would give women individual control over their own fertility. Sanger was the founder of the American Birth Control League, the precursor organization to Planned Parenthood. Although it’s not widely promoted, her strong advocacy of birth control was not only rooted in a conviction that women deserved control over their individual reproductive decisions. Sanger also believed society needed to exert control over who exactly reproduced in order to prevent reproduction in families that were genetically “unfit.”

  This philosophy—that society ought to exert an active control in determining who has children and who does not, in order to improve the gene pool—is called eugenics, and it has a terribly checkered history. Eugenics is generally divided into two types: positive eugenics is the promotion of reproduction among those considered genetically well-off; negative eugenics is the opposite, the intentional discouragement of reproduction among those deemed somehow less genetically fit. Sanger was an outspoken proponent of negative eugenics. In one pamphlet, she wrote:

  It is a vicious cycle; ignorance breeds poverty and poverty breeds ignorance. There is only one cure for both, and that is to stop breeding these things. Stop bringing to birth children whose inheritance cannot be one of health or intelligence. Stop bringing into the world children whose parents cannot provide for them. Herein lies the key of civilization.

  To be fair, Sanger was by no means among the most radical eugenicists. She explicitly rejected the extreme—and horrible—ideas of people like William Robinson, who proposed killing the children of those deemed “unfit.” She publicly criticized the anti-Semitism of Nazi Germany, which based its plan for creation of a “master race” on eugenics. And, ultimately, she believed that individuals, not the government, must have the power to make their own reproductive decisions, which squared nicely with her support for development of female contraception.

  The campaign for birth control is not merely of eugenic value, but is practically identical with the final aims of eugenics…. We are convinced that racial regeneration, like individual regeneration, must come ‘from within.’ That is, it must be autonomous, self-directive, and not imposed from without.

  Katharine McCormick’s motives don’t seem tainted by the eugenic influence. A lifelong advocate of women’s rights, beginning with the suffrage movement, she also had a keen interest in science. She was the second woman to graduate from the Massachusetts Institute of Technology and the first to do so with a degree in science. In 1906, her husband, Stanley McCormick, an heir to the American harvester fortune, was diagnosed with severe schizophrenia—a disease that also plagued his sister. Tone writes: “his sufferings, combined with her fears that schizophrenia could be inherited, forged in Katharine a resolve to stay childless and made her an early convert to contraception.” McCormick and Sanger met in 1917 and began a long collaboration to give women individual control over their own fertility.

  In 1951, the same year that Djerassi had his synthesizing breakthrough, Sanger met a gifted biologist named Gregory Pincus, who had been studying hormones and fertility for a quarter century. Sanger encouraged Pincus to begin research into an oral contraceptive for women and secured a small grant to help him begin. Sanger introduced McCormick to Pincus and his work in 1953, and she provided him with a massive increase in funding that set the stage for the ultimate development of the first oral contraceptive. The Pill was approved by the FDA in
1960 and was the most popular form of birth control in the United States by 1965. As Tone describes, it took the country by pharmaceutical storm:

  It was one of the greatest inventions of the twentieth century, the capstone of decades of pharmaceutical research. It inspired songs, cartoons, political debate, and grateful letters from women around the world who flocked to their physicians’ offices for prescriptions. The Catholic Church condemned it as immoral, and several African-American leaders denounced it as technology of genocide…. But no matter how Americans felt about it, the object of excitement needed no special introduction. By the mid-1960s, Americans knew the wonder drug of the decade simply as “the Pill.”

  When the Pill is prescribed as it was originally marketed, and usually still is, women take the Pill every day for twenty-one days and then either take a week off or take a placebo pill (one with no active ingredient) for seven days. During the week in which a woman is not taking the Pill, but taking the placebo or nothing, she will experience a period of bleeding similar to and occasionally lighter than normal menstruation. Many people assume this period of bleeding is menstruation, believing women go off the Pill so they can have their period. In fact, the bleeding is not menstruation per se; it’s actually a symptom of withdrawal from the hormones. The Pill is sold this way because its original marketers assumed women would be more receptive to a product that preserved the appearance of a normal menstrual cycle along with its monthly reminder and confirmation of a lack of pregnancy.

  If a woman were to take daily doses of the actual Pill, she would live a period-free existence. And many doctors have quietly advised patients who experience especially painful periods to do exactly that. In 2003, Barr Pharmaceuticals introduced Seasonale, a version of the Pill prescribed in such a way to reduce a woman’s period from once a month to just four times a year. The trick to Seasonale is essentially all in the packaging—instead of twenty-one active pills and seven placebos, Seasonale is sold in packs of ninety-one pills, containing eighty-four active pills and seven placebos.

  Of course, the obvious question is, why stop there? If you can sell a version of the Pill that eliminates eight periods a year, why not go for broke and sell one that gets rid of them entirely? That’s what drugmaker Wyeth decided to do with its new version of the Pill, called Lybrel, that was approved by the FDA in 2007. It’s not an instant end to bleeding—Wyeth’s own website advises that breakthrough bleeding is common as women adjust to the constant hormonal treatment, and warns, “When prescribing Lybrel, the convenience of having no scheduled menstrual bleeding should be weighed against the inconvenience of unscheduled breakthrough bleeding and spotting.” The biggest problem with Lybrel is that, because women don’t menstruate regularly, if they do become pregnant they may not know it.

  Breakthrough bleeding and spotting are actually the most common side effects of oral contraceptives, although as side effects go, they fall in the inconvenient but relatively inconsequential category. In many women, the Pill helps to reduce acne, which is generally considered a benefit, and is sometimes linked to larger breast size: Tone notes that the sale of C-cup bras in the United States climbed by 50 percent from 1960 to 1969.

  The Pill has long been rumored to cause weight gain, although the evidence is less than conclusive. British researcher Dr. Sunanda Gupta conducted an extensive review of medical literature regarding weight gain and the Pill. Her conclusion? No evidence. And the report also suggested that rumors of this side effect had a side effect of their own—adolescent pregnancy. Gupta believes adolescent girls’ fear of weight gain discourages many of them from using oral contraceptives, contributing to Britain’s high rate of teen pregnancy.

  In terms of serious side effects, the combination Pill is associated with some risk of cardiovascular disease, especially blood clots that can lead to heart attack or stroke. Those risks are magnified in women who smoke. The mini-pill (progestin only) is thought to be somewhat safer for women smokers. There is also some evidence that the Pill may be associated with an increased risk of depression. But taking the Pill is not all bad. Multiple studies have produced evidence that oral contraception use can lower rates of endometrial cancer (some studies found protection from ovarian cancer as well, but this is still controversial). Progestin, the synthetic version of progesterone that is one of the combined Pill’s two main ingredients, has been shown to contribute to a decrease in serotonin levels in the brain. Serotonin is thought to help to regulate mood and emotional well-being; low levels of serotonin are linked to depression. Prozac and other similar drugs in its class, selective serotonin reuptake inhibitors, or SSRIs, help to treat depression by preventing serotonin’s reabsorption into neurons. This boosts the overall serotonin levels in the synapses, between neurons in the brain. A recent study by Dr. Jayashri Kulkarni of Australia’s Alfred Psychiatry Research Center found that women using the Pill showed significantly more symptoms of depression than a matched group who were not using the Pill. More research is clearly in order—but if you feel that a bad case of the blues descended on you when you started taking the Pill, talk to your doctor about it.

  But the most unexpected side effect of the Pill may involve its playing chemical havoc in the one area it’s supposed to help—your love life. Remember the T-shirt study run by Claus Wedekind that was the first to reveal that women were more attracted to the smell of men whose HLA genes (the genes that code for a critical part of our immune systems) differed from their own? The basic rule is this: when it comes to body odor and HLA, opposites don’t just attract, they can apparently smell better too.

  With one big exception.

  Beginning with the initial Wedekind research, a few studies have shown that the Pill seems to shift women’s olfactory preferences (in men, that is) into reverse. Instead, of preferring men with dissimilar HLA, they prefer men with similar HLA. Now, remember that HLA diversity—having dissimilar HLA between partners—a marker for genetic variability between the couple is associated with better fertility and gives your offspring a better chance at a stronger immune system. That’s why scientists believe women are naturally attracted to the smells of men with somewhat dissimilar HLA; you’re more likely to reproduce and more likely to produce children with strong immune systems, two big pluses from evolution’s point of view.

  A very recent study published in 2008 by Craig Roberts and colleagues at the University of Newcastle in the United Kingdom examined the smell preferences of a group of women before and after they began using the Pill. They also compared those results to a control group of women who were never on the Pill. There was one clear conclusion, as the authors wrote, “Across tests, we found a significant preference shift towards MHC [HLA] similarity associated with pill use, which was not evident in the control group.”

  If the Pill throws you off the scent, it could actually have a dramatic impact on whether Mr. Right is actually right for you. Dr. Dustin Penn, director of the Konrad Lorenz Institute for Ethology in Vienna, Austria, said, “It wouldn’t surprise me if sabotaging our reproductive machinery would lead to faulty mate choice.” According to Roberts and coauthors, “We do not know whether the change in preferences related to pill use is sufficiently strong to influence partner choice, but it could do so if odor plays a significant role in actual human mate choice.”

  And psychologist Rachel Herz, author of Scent of Desire, reiterated to me that if the Pill contributes to a woman choosing a mate with similar HLA, “it’s like picking your cousins as marriage partners. It constitutes a biological error.” So how does the Pill point your nose in the wrong direction?

  As we discussed, by elevating the level of hormones circulating through a woman’s body, the Pill essentially tricks her body into thinking it’s pregnant, preventing ovulation. No ovulation, no chance of pregnancy. Of course, as everybody knows, pregnant women experience a huge array of changes, and we’re not just talking about the bump or a sudden predilection for pickles. Wedekind thinks women’s odor preferences may change during pregn
ancy too. Once a woman is pregnant, she instinctively looks to find the safest environment for her unborn child—family, of course, is deeply associated with safety. So it’s possible that, when pregnant, a woman is more attracted by the smell of family than the smell of a potential mate—she’s sniffing for safety, not sniffing for sex.

  So what’s to be done about it? Herz has a straightforward recommendation: When it comes to women “who are currently trying to find the man that they want to have a family with, in this quest, prior to embarking on it, they should go off the Pill. And they should also try to subtly tell their men that they become involved with not to put on heavy fragrance because the fragrance can mask their body odor as well.”

  On the other hand, if you were on the Pill when you found the man of your dreams, according to Herz, don’t worry about it. If you’re in love, you’re in love; it’s too late. And guys, don’t worry that your girlfriend, fiancée, mistress, or wife is suddenly going to hate the way you smell when she goes off the Pill (as long as you have a good relationship, anyway). As Herz says:

  Once you’ve fallen in love with someone, once the emotional attachment has been made to an individual, they could smell like a garbage truck and you’d be attracted to that smell. If you’re healthy, and I’ve been on the Pill, and you’ve been wearing cologne, I don’t really know how you truly smell. Once you stop wearing cologne, and you’re sweating around the house, and now I know how you really smell because we’re past that stage of courtship, then how you smell now is going to be associated with how I feel about you. And if I’m in love with you, then that’s going to be how I associate the meaning of that smell.