What the Dog Saw

protect women against unwanted pregnancy,” Loretta McLaughlin writes in her marvelous 1982 biography of Rock. Not long before the Pill’s approval, Rock traveled to Washington to testify before the FDA about the drug’s safety. The agency examiner, Pasquale DeFelice, was a Catholic obstetrician from Georgetown University, and at one point, the story goes, DeFelice suggested the unthinkable—that the Catholic Church would never approve of the birth-control pill. “I can still see Rock standing there, his face composed, his eyes riveted on DeFelice,” a colleague recalled years later, “and then, in a voice that would congeal your soul, he said, ‘Young man, don’t you sell my church short.’”

In the end, of course, John Rock’s church disappointed him. In 1968, in the encyclical “Humanae Vitae,” Pope Paul VI outlawed oral contraceptives and all other “artificial” methods of birth control. The passion and urgency that animated the birth-control debates of the sixties are now a memory. John Rock still matters, though, for the simple reason that in the course of reconciling his church and his work he made an error. It was not a deliberate error. It became manifest only after his death, and through scientific advances he could not have anticipated. But because that mistake shaped the way he thought about the Pill—about what it was, and how it worked, and most of all what it meant—and because John Rock was one of those responsible for the way the Pill came into the world, his error has colored the way people have thought about contraception ever since.

John Rock believed that the Pill was a “natural” method of birth control. By that, he didn’t mean that it felt natural, because it obviously didn’t for many women, particularly not in its earliest days, when the doses of hormone were many times as high as they are today. He meant that it worked by natural means. Women can get pregnant only during a certain interval each month, because after ovulation their bodies produce a surge of the hormone progesterone. Progesterone—one of a class of hormones known as progestin— prepares the uterus for implantation and stops the ovaries from releasing new eggs; it favors gestation. “It is progesterone, in the healthy woman, that prevents ovulation and establishes the pre- and postmenstrual ‘safe’ period,” Rock wrote. When a woman is pregnant, her body produces a stream of progestin in part for the same reason, so that another egg can’t be released and threaten the pregnancy already under way. Progestin, in other words, is nature’s contraceptive. And what was the Pill? Progestin in tablet form. When a woman was on the Pill, of course, these hormones weren’t coming in a sudden surge after ovulation and weren’t limited to certain times in her cycle. They were being given in a steady dose, so that ovulation was permanently shut down. They were also being given with an additional dose of estrogen, which holds the endometrium together and—as we’ve come to learn— helps maintain other tissues as well. But to Rock, the timing and combination of hormones wasn’t the issue. The key fact was that the Pill’s ingredients duplicated what could be found in the body naturally. And in that naturalness he saw enormous theological significance.

In 1951, for example, Pope Pius XII had sanctioned the rhythm method for Catholics because he deemed it a “natural” method of regulating procreation: it didn’t kill the sperm, like a spermicide, or frustrate the normal process of procreation, like a diaphragm, or mutilate the organs, like sterilization. Rock knew all about the rhythm method. In the 1930s, at the Free Hospital for Women, in Brookline, Massachusetts, he had started the country’s first rhythm clinic for educating Catholic couples in natural contraception. But how did the rhythm method work? It worked by limiting sex to the safe period that progestin created. And how did the Pill work? It worked by using progestin to extend the safe period to the entire month. It didn’t mutilate the reproductive organs, or damage any natural process. “Indeed,” Rock wrote, oral contraceptives “may be characterized as a ‘pill-established safe period,’ and would seem to carry the same moral implications” as the rhythm method. The Pill was, to Rock, no more than “an adjunct to nature.”

In 1958, Pope Pius XII approved the Pill for Catholics, so long as its contraceptive effects were “indirect”—that is, so long as it was intended only as a remedy for conditions like painful menses or “a disease of the uterus.” That ruling emboldened Rock still further. Short-term use of the Pill, he knew, could regulate the cycle of women whose periods had previously been unpredictable. Since a regular menstrual cycle was necessary for the successful use of the rhythm method—and since the rhythm method was sanctioned by the Church—shouldn’t it be permissible for women with an irregular menstrual cycle to use the Pill in order to facilitate the use of rhythm? And if that was true, why not take the logic one step further? As the federal judge John T. Noonan writes in Contraception, his history of the Catholic position on birth control:

If it was lawful to suppress ovulation to achieve a regularity necessary for successfully sterile intercourse, why was it not lawful to suppress ovulation without appeal to rhythm? If pregnancy could be prevented by pill plus rhythm, why not by pill alone? In each case suppression of ovulation was used as a means. How was a moral difference made by the addition of rhythm?

These arguments, as arcane as they may seem, were central to the development of oral contraception. It was John Rock and Gregory Pincus who decided that the Pill ought to be taken over a four-week cycle—a woman would spend three weeks on the Pill and the fourth week off the drug (or on a placebo), to allow for menstruation. There was and is no medical reason for this. A typical woman of childbearing age has a menstrual cycle of around twenty-eight days, determined by the cascades of hormones released by her ovaries. As first estrogen and then a combination of estrogen and progestin flood the uterus, its lining becomes thick and swollen, preparing for the implantation of a fertilized egg. If the egg is not fertilized, hormone levels plunge and cause the lining—the endometrium—to be sloughed off in a menstrual bleed. When a woman is on the Pill, however, no egg is released, because the Pill suppresses ovulation. The fluxes of estrogen and progestin that cause the lining of the uterus to grow are dramatically reduced, because the Pill slows down the ovaries. Pincus and Rock knew that the effect of the Pill’s hormones on the endometrium was so modest that women could conceivably go for months without having to menstruate. “In view of the ability of this compound to prevent menstrual bleeding as long as it is taken,” Pincus acknowledged in 1958, “a cycle of any desired length could presumably be produced.” But he and Rock decided to cut the hormones off after three weeks and trigger a menstrual period because they believed that women would find the continuation of their monthly bleeding reassuring. More to the point, if Rock wanted to demonstrate that the Pill was no more than a natural variant of the rhythm method, he couldn’t very well do away with the monthly menses. Rhythm required “regularity,” and so the Pill had to produce regularity as well.

It has often been said of the Pill that no other drug has ever been so instantly recognizable by its packaging: that small, round plastic dial pack. But what was the dial pack if not the physical embodiment of the twenty-eight- day cycle? It was, in the words of its inventor, meant to fit into a case “indistinguishable” from a woman’s cosmetics compact, so that it might be carried “without giving a visual clue as to matters which are of no concern to others.” Today, the Pill is still often sold in dial packs and taken in twenty-eight-day cycles. It remains, in other words, a drug shaped by the dictates of the Catholic Church—by John Rock’s desire to make this new method of birth control seem as natural as possible. This was John Rock’s error. He was consumed by the idea of the natural. But what he thought was natural wasn’t so natural after all, and the Pill he ushered into the world turned out to be something other than what he thought it was. In John Rock’s mind the dictates of religion and the principles of science got mixed up, and only now are we beginning to untangle them.

2.

In 1986, a young scientist named Beverly Strassmann traveled to Africa to live with the Dogon tribe of Mali. Her research site was the village of Sangui in the Sahel, about 120 miles south of Timbuktu. The Sahel is thorn savannah, green in the rainy season and semi-arid the rest of the year. The Dogon grow millet, sorghum, and onions, raise livestock, and live in adobe houses on the Bandiagara escarpment. They use no contraception. Many of them have held on to their ancestral customs and religious beliefs. Dogon farmers, in many respects, live much as people of that region have lived since antiquity. Strassmann wanted to construct a precise reproductive profile of the women in the tribe, in order to understand what female biology might have been like in the millennia that preceded the modern age. In a way, Strassmann was trying to answer the same question about female biology that John Rock and the Catholic Church had struggled with in the early sixties: what is natural? Only, her sense of natural was not theological but evolutionary. In the era during which natural selection established the basic patterns of human biology—the natural history of our species—how often did women have children? How often did they menstruate? When did they reach puberty and menopause? What impact did breast- feeding have on ovulation? These questions had been studied before, but never so thoroughly that anthropologists felt they knew the answers with any certainty.