VANCOUVER, CANADA—In the past half-century, few things have transformed society as profoundly as oral contraceptives. First introduced as the U.S. Federal Drug Administration-approved drug Enovid in 1961, "the pill" works by providing a constant supply of estrogen and progesterone, which block the hormones that lead to ovulation. About 85% of women in the United States will take contraceptive drugs for an average of 5 years. Given its widespread use by a generally healthy and young population, what is known about the risks and benefits of oral contraception? What are the alternatives? And when will we see "the pill" for men?
Yesterday, Ronald Burkman, an obstetrician-gynecologist at Tufts University School of Medicine, gave a talk on these topics at the annual meeting of the American Association for the Advancement of Science (which publishes ScienceNOW). I sat down with him to chat about 50 years of the contraceptive “wonder drug.”
Q: What interested you in studying contraception?
R.B.: Its significant public health impact. When you realize there are about 34 million unintended, unplanned pregnancies that occur each year, primarily in developing countries, you realize, for countries in sub-Saharan Africa, not having contraception has a significant impact on maternal mortality. If you’re in sub-Saharan Africa in some countries, your lifetime risk of dying in pregnancy is 1 in 30. Your lifetime risk of dying of pregnancy in this country is less than 10 per 100,000.
Q: In your talk you asserted the pill's risks of blood clotting, lung artery blockage, heart attack, and stroke are minimal. What about cancer risks?
R.B.: One or two cancers may be increased by the pill—benign and malignant liver tumors—but those occur at one per million or one per 2 million, so it’s not a big public health issue. We’ve certainly been looking at women on the pill and the risk of cervical cancer, and there’s some evidence that it might occur, but again, it doesn’t go immediately to serious cervical cancer. But breast cancer? Not a lot of issue there. In fact, a study that I was involved with looked at women of reproductive age group and identified no increased risk of breast cancer, and we showed that there’s protective effects against endometrial and ovarian cancer.
Q: Other speakers in your session described the pill's benefits beyond contraception, from menstrual cycle regularity to decreased risk of ovarian and endometrial cancers and increased bone mass. Given these benefits, would you tell women to use oral contraception just for their health?
R.B.: Yeah, you could use it for medical reasons. Certainly treatment of endometriosis [a disorder in which uterus cells grow outside the uterus], irregular menstrual cycles, young women with dysmenorrhea [painful periods]—it’s one of the top treatments for it. So there’s a variety of reasons where oral contraceptive can be used in a noncontraceptive way. But putting healthy women on anything to say that it has a health benefit, ... that becomes a potential issue. And the reality is, a lot of people use it anyway for contraception.
Q: Are these benefits associated with long-term use only or short-term use also?
R.B.: One year of use does provide benefit; more prolonged use provides additional benefit.
Q: Does the pill have side effects on mood?
R.B.: It can. It varies from individual to individual. [Some pill formulations] will probably have an improvement [on mood]. Secondly, a lot of people worry about weight gain. Well, the data are pretty consistent: The pill does not cause any weight gain.
Q: What are the challenges to developing "the pill" for men?
R.B.: Some of the challenges are, is this stuff reversible? Clearly, if you tie the tubes, vasectomy, it’s very, very effective. But that’s not what most people want. Some of the [candidate male contraceptive] drugs, such as high-dose testosterone treatment, have side effects, potentially even cardiovascular side effects. And [the infertility effect] isn’t reversible—fully. So [some of these efforts] fell by the wayside.
Q: Do you think the main barriers to developing oral contraceptives for men have been societal or biological?
R.B.: I can assure you that if [pharmaceutical companies] could develop one, it’d be a blockbuster, so they have a lot of interest in digging through. It’s just the science has not lent itself yet so far with any breakthrough that’s reversible, easy to use, et cetera. If someone said here’s a pill you take for a month at a time, I think men would sign up readily. In reality, nothing’s there. Part of the problem is you already have a very effective form of contraception. The [contraception] market’s saturated now.
Q: Where do you see the field going?
R.B.: I think contraception will be a significant issue in terms of dealing with excess population growth. It’s how you deal with the unintended pregnancy rate worldwide that’s key. I also take a long-term view with global warming. Why do we have some of these effects on Earth’s atmosphere? It’s because of the population. In Brazil, they cut down the forest for wood to build houses. China [implemented] the one-child [rule]. But they also have the other effect—more people went into the middle class, and what do they do? They copied [the polluting U.S. lifestyle]. It's a huge problem.