While researching my hypothesis linking oral contraceptive use to the development of autism in children, I wondered about why so many women are still using a drug that has dangerous side-effect and could cause neurodevelopmental disorders in offspring. The simple answer seems to be lack of accurate medical information. Not only do individual women lack critical information about the pill, but the support systems women depend on for advice and help with decision-making also seem to lack information about the pill.
All health choices are complex and influenced by multiple variables that all interact. There are multiple levels, underlying determinants of health behaviors, which are relevant for understanding why oral contraceptives are still the primary method of choice in the United States. The following influencing factors are not exhaustive, but do shed light on why pill use is so prevalent in the U.S. Simply put, we don’t know better.
Personal Factors Influencing Decision-Making about Oral Contraceptives
Limited options for family planning. Effective contraception is thought to have a positive effect on subsequent outcomes related to income, family stability, mental health, happiness, and the well-being of the children. Contemporary women want to be in control of their reproductive lives but unfortunately, there are few options available to them. Eighty two percent of sexually active women in the U.S. plan their families by using oral contraceptives.
Lack of knowledge about oral contraceptives safety and efficacy. U.S. women use oral contraceptives primarily because they are marketed as effective in preventing pregnancy and relatively safe for them to take. However, according to a 2013 survey conducted by the American College of Nurse Midwives (ACDM), the majority of U.S. women are misinformed about birth control’s effectiveness. Just one in five women were able to correctly identify the most effective form of contraception that is currently available. Most said they didn’t feel well-informed about contraception in general or about different birth control options. Seventy percent said they were very knowledgeable about abstinence, while less than 50% said the same for oral contraceptives. Only 21% said they knew a lot about the IUD. Interestingly, the contraceptive methods that the participants ranked lower, the IUD and the implant, are much more effective because they are less prone to user error such as forgotten pills. This study also found that women who use an IUD are 20 times less likely to accidentally get pregnant than the women who use the pill. And yet, less than 6% of women in the U.S. use the IUD.
If we, as women are misinformed or lack knowledge of the efficacy of the pill, do we understand the risks involved with taking the pill? Can we understand the adverse effect of endocrine disrupting compounds, the long term consequences? I doubt it. It seems that the safety of the pill has entered into the realm of conventional wisdom and that the status quo goes unchallenged.
Presumed ease and self-efficacy. In addition to safety and efficacy, the pill is said to be easy to use and convenient leading women to believe that they will be able to follow the pill regimen. In reality, some women fall short of their perceived ability to follow the pill regimen. Even though birth control pills are 99 percent effective when taken correctly, many women don’t always take them exactly as directed. The CDC estimates that about 9% of the women who use the pill end up accidentally getting pregnant. Women may over estimate their ability to follow through with the attentiveness required. And, those that have low confidence in their ability to use the method are more likely to misuse or discontinue use. So, not only are there demonstrated knowledge gaps about efficacy, there may also be problems with self-efficacy and proper adherence to taking the pill regularly.
At the intrapersonal level, U.S. women are influenced by the desire to prevent pregnancy in an easy, safe, effective manner. However, we may elect to use oral contraceptives even though we do not adequately understand how they work or understand the importance of adherence to a strict daily dosing regimen. We may also select oral contraceptives even though they are not the most effective choice of birth control available for us. And, there are knowledge gaps which may lead us to overestimate the effectiveness and safety of oral contraceptives.
Contraception Choices Influenced by Family and Friends
Parents, peers and partners rely on personal beliefs and inadequate knowledge. Parents are encouraged to be the primary sex educators of their children, but once again, scientists have discovered that significant numbers of parents have misunderstandings about all forms of contraception. It is no surprise that scientists conclude that parents should be provided with medically accurate information rather than relying upon their partial knowledge and beliefs about contraception. Women of all ages may at times rely on parental knowledge that is incomplete or inaccurate.
Research confirms that peers exert a significant influence on both sexual activity and contraceptive use. Women of all ages may turn to the advice and counsel of their friends. They may be persuaded to choose the same option as recommended by their friends, whether or not the friend is knowledgeable about contraception.
Studies support the notion that a woman’s partner may have major influence on use or non-use of a contraceptive method. However, couples may often disagree on different aspects of contraceptive choice and practice due to differences in fertility values, or misconceptions about attitudes, and intentions of the other spouse. Furthermore, the nature and the quality of the relationship between the partners is a major factor in contraceptive choice and use. Research suggests that contraceptive use is influenced by peers, and that a desire to please one’s sexual partner appears to outweigh advice provided by a close friend.
Healthcare providers bias toward oral contraceptives. The prevailing widespread acceptance and promotion of oral contraceptives shows that U.S. physicians believe that the pill is safe, effective, and that it is good for women. However, doctors and nurses may not always be the most reliable sources of information. According to a study published in the American Journal of Public Health, physicians bias their responses in favor of methods doctors most frequently prescribe. And, they tend to provide lower-than-best failure rates for oral contraceptives and IUDs, higher-than-typical failure rates for condoms, and standard rates for foam and diaphragms. Despite their safety, methods like condoms, spermicides, and the withdrawal method, earn disproportionately low ratings by doctor’s offices and clinics.
Some argue that natural family planning is the least expensive and safest of all contraceptive methods. However, it is often omitted as an effective and valid method for preventing pregnancy. Planned Parenthood reports providing fertility awareness-based methods to 0.2% of clients seeking contraceptives, whereas hormonal methods were provided to 64%.
It turns out that health care providers may also have some knowledge gaps. In 2010, a study was conducted to assess provider knowledge about contraception. Data collected from health care providers, physicians, nurse practitioners, and physician assistants showed a lack of consistent and accurate knowledge about contraception among providers. This lack of knowledge about contraception among providers has the potential to significantly affect providers’ ability to offer quality contraceptive care.
It isn’t surprising then that medical students may also need to improve their knowledge of contraception. Studies suggest that sexual beliefs and mores of students in medical professions might influence their ability to care for patients’ contraception concerns. A 2010 study examined contraceptive usage patterns in North American medical students. The study showed substantial differences in contraceptive use based on demographics, even at the highest education levels. And, that students who responded that they were comfortable discussing sexual issues with patients were more likely to use highly effective contraceptive methods, like the pill, themselves. In conclusion, scientists found that the personal contraception choices of medical students might influence their ability to correctly express contraception information to their patients. In addition, they reported that medical students might personally benefit from improved knowledge of effective contraceptive practices.
A recent study of internal medicine resident and faculty providers examined the occurrence of contraceptive counseling provided to women of reproductive-age during a prevention-focused visit. Even though 95% of the medicine faculty and residents agreed that contraceptive counseling is essential, only 25% of them reported providing contraceptive counseling routinely or more than 80% of the time to reproductive-age women during a prevention-focused visit. The reason for this? Inadequate knowledge of contraceptive methods was an obstacle to providing contraceptive counseling. This was reported by more than 70% of providers.
At the interpersonal level, parents, peers, partners, and healthcare providers may or may not provide accurate information to women who seek their counsel in choosing a contraceptive. Knowledge gaps are prevalent throughout the interpersonal level of influence.
Organizational and Institutional Biases that Influence Contraceptive Choices
Lack of comprehensive sex education contributes to misunderstanding contraception. Lack of contraceptive knowledge is due in part to the absence of providing comprehensive reproductive health and sexuality courses in U.S. schools. Since the 1980’s federal funding has focused on abstinence-only programs and consequently, the vast majority of children, young and middle-aged adults have not received comprehensive sex education. Evidence-based educational materials, programs, and policies are not commonly available. Although there is lack of evidence that abstinence-only education reduces the risks for pregnancy, these are the programs that continue to receive government funding and continue to be taught in the U.S. Therefore, people in the U.S. rely on family, friends, and healthcare providers for information about contraception. As pointed out, the people on whom they rely may lack medically accurate information regarding contraception.
Religious and cultural factors influence contraception. Religious and cultural influences may influence acceptance and choice of contraception. Different religions may interpret religious teachings on this subject in disparate ways, and people may choose to accept or ignore various religious teachings.
Invested advocates push oral contraceptive use. Planned Parenthood has positioned itself as the go-to organization for women’s sexual and reproductive health nationwide. Planned Parenthood has an international presence and a user-friendly, comprehensive web-site. Any mid-sized city will have a well-publicized Planned Parenthood clinic that carries national credibility. It has a research affiliate, the Guttmacher Institute, which also has a significant web presence. The mainstream credibility of Planned Parenthood is enhanced by the organization’s government support. And, their services are offered free or at a low price. Whether or not a woman has had a personal experience with Planned Parenthood, the existence and persistence of this organization has influenced the health behavior choices of most women in the U.S. And, Planned Parenthood has been heavily invested in the pill since its founding mothers first encouraged the development of oral contraceptives.
Pharmaceuticals companies promote oral contraceptives as lifestyle drugs. Women may not know that most of today’s methods of contraception, including hormonal methods, depend on mechanisms of action discovered before 1960 and on delivery methods developed during the 1960’s and early 1970’s. The latest methods have for the most part been adaptations of existing technologies that offer variations on hormone dosages and delivery methods, rather than true technological breakthroughs. It should be pointed out that these advances have largely usurped efforts to discover new contraceptive approaches.
In general, new birth control drug discovery and development is currently led by the private and not-for-profit sectors, but big pharmaceutical and biotechnology companies, for the most part, have deserted the field of contraceptive research and development. Instead of developing new technologies, pharmaceutical companies are marketing existing oral contraceptives in new and creative ways. Currently, they are pushing the pill as a lifestyle drug through media campaigns.
The trend among brands of the pill is marketing them as lifestyle drugs. Catchy phrases are used to convey the idea of female empowerment and to convince women to choose one oral contraceptive over another. Slogans range from taking control over one’s period, to “we’re not gonna take it,” which suggests to women that they no longer need to deal with PMS and period related symptoms. Minimizing discomfort is a product highlight. The notion is, “Why accept an uncomfortable situation when this new pill can fix it.” Some slogans suggest that the pill allows a woman to express herself and her individuality. The commercials steer clear of the true function of birth control pills and instead try to control thoughts, behaviors, and, of course, spending habits. Once again, misinformation about the pill is being conveyed and might influence women to choose the pill.
At the organizational level, women of all ages are at risk for receiving incomplete or misinformation about oral contraceptives. We do not receive comprehensive sex education in U.S. schools and so, we do not receive adequate, medically reliable information about contraception. We may have to rely on biased information from organizations who are heavily invested in the use of the pill. Certainly, the lack of new methods provided by pharmaceutical companies limit our choices in birth control. In addition, pharmaceutical companies manipulate us to use the pill through calculated marketing schemes, which misrepresent the pill and mislead us.
Societal Bias Towards Oral Contraceptive Use
Long term consequences of oral contraceptive use have not been adequately studied. As pointed out earlier, most of the research done on the pill was done before 1988, almost thirty years ago, when contraceptive research fell from the list of the top 35 medical research interests. Biomedical science moved on to more pressing research topics leaving women with limited contraceptive options.
I am astonished at the lack of research on the neurodevelopmental effects of the pill on offspring. When I began my research I couldn’t find anything on Pubmed and my search of the Annual Reviews journal database of over 30,000 biomedical papers revealed nothing. I could not find research investigating a link between oral contraceptive use and the increase in prevalence of autism spectrum disorders. I could find extensive research about the efficacy of oral contraceptives and about the effects of use on women, but almost nil on the neurodevelopmental effects of use on the offspring of those that use it.
The question about the effects of maternal use of oral contraceptives on progeny was first raised in the appendix of the 1966 FDA report on oral contraceptives. Dr. Roy Hertz, a widely acclaimed physician scientist, outlined the potential effects of oral contraceptives on germ cells. In striking terms he wrote,
“An unequivocal abnormality produced by estrogen-progestogen is the suppression of ovulation itself. It is only reasonable to consider the ultimate fate of the ovum that would have been normally released from the ovary. We do not know whether the ovum dies or survives. If it survives, is it altered in any way?”
Hertz suggested that statistical and clinical considerations indicated that for an adequate analysis of this problem a population of 100,000 children would be required. Still he warned that, “The suppression of ovulation for a four year period may be reflected in the quality of the ova subsequently released even from an ovary in which the histological findings appear to be normal”. The studies that Hertz recommended have not been done.
ACOG endorses oral contraceptives based on conventional wisdom. The American College of Obstetrics and Gynecology (ACOG) is a nonprofit organization of women’s health care physicians advocating highest standards of practice, continuing member education and public awareness of women’s health issues. ACOG maintains that oral contraceptives are a safe method to avoid an unwanted pregnancy and that the overall risks of taking oral contraceptives are much less than the risks of pregnancy.
ACOG also advises that oral contraceptives are safe for teenagers and that the benefits associated with the use of oral contraceptives outweigh the risks, particularly those of pregnancy. It seems unconscionable to introduce an endocrine disrupting agent to a developing teenager. While teen safety is of the utmost importance, concern for their own reproductive health and for their future children should be taken into consideration. If taking the pill begins in the teen years, ovum could be exposed to the endocrine disrupting compounds found in the pill for decades. The possible epigenetic repercussions are striking.
ACOG doctors believe that oral contraceptives are safe enough that women should be able to buy birth control pills over-the-counter (OTC) at pharmacies without a prescription. ACOG recognizes that selling OTC birth control pills comes with risks, but it reasons that like any drug, the pill has potential side effects, and might be misused or used by women who should not take the drug. However, ACOG concludes that these concerns are outweighed by the benefits. ACOG reports that increasing women’s access to birth control in this way could reduce the rate of unplanned pregnancies in the United States even though the rate has not changed in the last 20 years. How can ACOG conclude that after 20 years of available birth control, continued oral contraceptive use will change the rate of unplanned pregnancies?
ACOG contends that women could use OTC oral contraceptives safely because of the rarity of venous thromboembolism (VTE) and because their data support women’s ability to self-screen for possible contraindications. This is problematic based on findings that show so many existing knowledge gaps about contraception in general and the pill in particular. Are women qualified to ascertain contraindications? And, with the recent information that only 30% of ACOG guidelines are based on research, are women to accept a recommendation that is based on personal bias, opinion and conventional wisdom? At present it is hard to argue who is better qualified to ascertain risk and contraindications, physicians or women. It appears that there is a systemic lack of accurate knowledge and the knowledge that is available may be biased and/or unreliable.
If given the opportunity to purchase oral contraceptives over-the-counter, would women be more or less likely to investigate the risks? In some countries where medications are available without prescriptions, the medication use tends to go down. This may be due to consumers evaluating the risks more deeply.
Drug labels lack important information about side-effects of oral contraceptives. Americans may assume that the text in a drug’s packaging represents the collective scientific knowledge about that medication, allowing doctors and patients to make informed health care decisions. In fact, negotiations between pharmaceutical companies and the FDA over warning labels are common during the drug approval process, with drug makers endeavoring to cherry-pick what is included in order to present their products in the best possible light. The FDA relies on the manufacturers to provide clinical trial results and other data the agency uses to evaluate their drugs and devices, and 70 % of the funds for FDA reviews comes directly from the industry through user fees. So, do the labels for oral contraceptives identify risk to the offspring? No, risk to offspring is not on the labels. Nor are many other side-effect listed.
FDA continues to turn a blind eye regarding long term consequences. The Food and Drug Administration (FDA or USFDA) is a federal agency of the United States Department of Health and Human Services. It is responsible for protecting and promoting public health through the regulation and supervision.
Of importance, is that the pill was approved before the FDA had rigorous requirements and prior to the passage of the 1962 Drug Amendments that ensured a far more regulatory environment for any drug that could be used by women of childbearing years. In addition, the main concern was for the efficacy of the drug in light of the risk of pregnancy for women. The safety requirement was met because the pill was very effective in preventing pregnancy. At the time of approval, there was no consideration at all for the possible adverse effects that might develop in the offspring of women who used the pill.
When the pill was approved, the FDA did not anticipate the danger of thromboembolism. It took a decade after the approval of the pill to establish a link between the two. Recall that the FDA approved the Yasmin line in 2006 and as of January 2012 there were 10,000 lawsuits against Bayer by women who suffered blood clots. Sadly, independent investigation revealed that three of the advisors on the FDA panel had research or financial ties to Bayer and a fourth was connected to marketing the generic version. After investigation (2012), the FDA concluded that Yasmin, YAZ, Safyral, and Beyaz, as well as the other generic birth control pills containing drospirenone (DRSP), may be associated with a higher risk for blood clots than those pills with other progestins, such as levonorgestrel.
And, who can forget the adverse effects of another endocrine disruptor called Diethylstilbestrol (DES)? It was prescribed to pregnant women between 1940 and 1971 to prevent miscarriage, premature labor, and related complications of pregnancy. DES use declined after studies in the 1950’s showed that it was not effective in preventing these prenatal problems. In 1971, researchers linked prenatal DES exposure to a type of cancer of the cervix and vagina called clear cell adenocarcinoma and then the FDA notified physicians that DES should not be prescribed to pregnant women. This was thirty years after it had been prescribed by physicians. And, DES use does have adverse transgenerational effects.
How are we to trust the FDA to protect us from the adverse effects of drugs like the pill when history shows that the FDA is unable or unwilling to do just that? The buck does stop with the FDA. They should be held accountable.
Similar to the observations in the other circles of influence, societal influences about the pill may be biased and knowledge gaps exist. Information regarding the pill may be based on conventional wisdom. It may be based on limited truth. It most certainly is based on the women using it and not on the safety of the children of those women who use it.
The Bottom Line on the Ubiquitous Use of Oral Contraceptives in the U.S.
The bottom line is that women take the pill because it is status quo. We do not know better or feel that we have any better options. The health system on all levels has failed us. It has failed to provide us with the accurate medical information that would steer us clearly away from taking endocrine disrupting compounds that have not been adequately studied for long term health consequences. It has failed to provide us with adequate analysis of the effects of these compounds on our children. It has failed to provide new technologies and new options. Instead it has repackaged and resold women an old fix to an age old dilemma that should be shared by both men and women.
I often wonder what would have happened if women and midwives had continued to develop their own solutions, yes, they had them, before the late nineteenth century policies were implemented to limit their access to birth control and abortion. Contraception was deemed immoral, a vice, and the distribution of the contraceptive devices that women had been using effectively was forbidden. These are the same policies that were promoted by the emerging medical profession of obstetricians, who sought to take control of the process of pregnancy and child birth, which previously had been the responsibility of mid-wives and lay healers. What would have happened if women had remained in control of developing contraceptives? Would we have done a better job of providing safer contraception? We will never know. Instead we have been subjected to uncontrolled human clinical experimentation on an unprecedented scale.
We Need Your Help
Hormones Matter needs funding now. Our research funding was cut recently and because of our commitment to independent health research and journalism unbiased by commercial interests we allow minimal advertising on the site. That means all funding must come from you, our readers. Don’t let Hormones Matter die.
This article was published originally on Hormones Matter on May 14, 2015.
- Hooper DJ. (2010) Attitudes, awareness, compliance and preferences among hormonal contraception users: a global, cross-sectional, self-administered, online survey. Clin Drug Investig. 2010;30(11):749-63
- Mcleroy K, Bibeau D, Steckler A, Glanz K. (1988) An ecological perspective on health promotion programs. Health Education Quarterly, 15(4), 351-377
- FDA consumer report 1990
- American College of Nurse Midwives www.midwife.org/acnm/…/2013 ACNM Contraception Survey …
- Jones RK, Beyond Birth Control: The Overlooked Benefits of Oral Contraceptive Pills, New York: Guttmacher Institute, 2011
- Dempsey AR, Johnson SS, Westhoff CL. (2011) Predicting oral contraceptive continuation using the transtheoretical model of health behavior change. Perspect Sex Reprod Health. 2011 Mar;43(1):23-9. doi: 10.1363/4302311. Epub 2010 Dec 22.
- Rocca C, Harper C. Do racial and ethnic differences in contraceptive attitudes and knowledge explain disparities in method use? Persect Sex Reprod Health. 2012;44930:150-158
- Shih G, Vittinghoff E, Steinauer J, and Dehlendorf C. Racial and Ethnic Disparities in Contraceptive Method Choice in California DOI:10.1363/4317311
- Jacobs J, Stanfors M. Racial and Ethnic Differences in U.S. Women’s Choice Of Reversible Contraceptives, 1995–2010 DOI: 10.1363/4513913
- Dehlendorf C, et.al. 2013 Racial/ethnic disparities in contraceptive use: variation by age and women’s reproductive experiences. Presented in poster format at the annual North American Forum on Family Planning of the Society of Family Planning, Seattle, WA, Oct. 6-7, 2013.
- Kaiser Family Foundation, Sex Education in America, 2000a. Kaiser Family Foundation, Decision-Making about Sex: SexSmarts, 2000b.
- Eisenberg ME, Bearinger LH, Sieving RE, Swain C, Resnick MD. (2004) Parents’ beliefs about condoms and oral contraceptives: are they medically accurate? Perspect Sex Reprod Health. 2004 Mar-Apr;36(2):50-7
- Laumann EO, Gagnon JH, Michael RT, Michaels S. (1994) The Social Organization of Sexuality: Sexual Practices in the United States. Chicago, IL: University of Chicago Press; 1994
- Ali MM, Amialchuk A, Dwyer DS. (2011) Social network effects in contraceptive behavior among adolescents. J Dev Behav Pediatr. 2011 Oct;32(8):563-71. doi: 0.1097/DBP.0b013e318231cf03.
- Frost JJ, Darroch JE. (2008) Factors associated with contraceptive choice and inconsistent method use, United States, 2004. Perspect Sex Reprod Health. 2008 Jun;40(2):94-104. doi: 10.1363/4009408.
- Severy LJ. Couples’ contraceptive behavior: Decision analysis in fertility. Address delivered at the Annual Meeting of the American Psychological Association, August 28, 1984, Toronto, Ontario, Canada.
- Miller WB. Why some women fail to use their contraceptive method: A psychological investigation. Fam Plann Perspect. 1986;18:27–32.
- Severy LJ, Silver SE. Two reasonable people: Joint decision-making in contraceptive choice and use. In Advances in Population Psychosocial Perspectives. Vol. 1. Severy LJ, ed. London: Jessica Kingsley Publishers; 1993.
- Whitley B Jr, Hern AL. (1991) Perceptions of vulnerability to pregnancy and the use of effective contraception. Pers Soc Psychol Bull. 1991;17:104–110.
- T J Trussell, R Faden, and R A Hatcher. Efficacy information in contraceptive counseling: those little white lies. American Journal of Public Health August 1976: Vol. 66, No. 8, pp. 761-767.
- Planned Parenthood www.plannedparenthood.org
- Dehlendorf C, Levy K, Ruskin R, Steinauer J. (2010) Health care providers’ knowledge about contraceptive evidence: a barrier to quality family planning care? Contraception. 2010 Apr;81(4):292-8. doi: 10.1016/j.contraception.2009.11.006. Epub 2009 Dec 11.
- Rowen TS, et.al. (2010) Contraceptive usage patterns in North American medical students Published Online: November 15, 2010 DOI: http://dx.doi.org/10.1016/j.contraception.2010.09.011
- Dirksen RR, Shulman B, Teal SB, Huebschmann AG. (2014) Contraceptive counseling by general internal medicine faculty and residents. J Womens Health (Larchmt). 2014 Aug;23(8):707-13. doi: 10.1089/jwh.2013.4567. Epub 2014 Apr 25
- American College of Nurse Midwives www.midwife.org/acnm/…/2013 ACNM Contraception Survey …
- Wright JD, et al. (2011) Scientific Evidence Underlying the American College of Obstetricians’ and Gynecologists’ Practice Guidelines. Online in press version, September 2011, Obstetrics and Gynecology 118 (3). Obstet Gynecol. 2011 Sep;118(3):505-12. doi: 10.1097/AOG.0b013e3182267f43
- Advocates for Youth. www.advocatesforyouth.org/…/article/450-effective-sex-education
- Teen Help. www.teenhelp.org
- http://www.plannedparenthood.org/health-info/birth-control/birth-control-pill#sthash.8DSCYFho.dpuf ]
- Harper MJK. In search of a second contraceptive revolution. Sexuality, Reproduction & Menopause. 2005 3(2):59–67.
- Ward J, Warren C, eds., Silent Victories: The History and Practice of Public Health in Twentieth Century America. New York: Oxford University Press, 2007 253–278.
- Guttmacher Institute http ://www.guttmacher.org/pubs/gpr/16/1/gpr160124.html
- PBS www.pbs.org/wgbh/amex/pill/…/timeline2.ht
- May, Elaine Tyler. America + The Pill. New York: Basic Books, 2010 168
- USA Today. http://usatoday30.usatoday.com/news/health/2010-05-07-1Apill07_CV_N.htm
- ACOG www.acog.org/~/media/For Patients/faq021.ashx
- ACOG otc –http://vitals.nbcnews.com/_news/2012/11/20/15314352-birth-control-pills-shouldnt-need-prescription-docs-say?lite
- Marks, Lara (2001). Sexual Chemistry: A History of the Contraceptive Pill. New Haven: Yale University Press. ISBN 0-300-08943-0.]