The possible side effects that Bancroft and co-investigators Stephanie Sanders, associate director and associate scientist at the Kinsey Institute, Cynthia Graham, an adjunct assistant professor of psychology at Indiana University Bloomington, and Dr. Judith Klein of Planned Parenthood of Central and Southern Indiana are trying to measure may be subtle, and they are difficult to pin down since many factors in a woman's life affect mood and sexuality. Yet even subtle side effects may be relevant to the high discontinuation rate for oral contraceptives.
Because of their efficacy, convenience, and lack of serious physical side effects (for low-dose pills), oral contraceptives are among the most popular method of fertility control. Despite their popularity--80 percent of U.S. women use oral contraceptives at some point in their lives, and, as of 1990, an estimated ninety-three million women were using oral contraceptives worldwide--a surprising number of women stop using them. In the United States, more than 25 percent of women discontinue use of the pill within the first year, usually during the first three months, and rates of discontinuation in other countries are often much higher: 67 percent in Singapore, 50 percent in Peru, and 48 percent in India. Although it is common for reports on use and discontinuance of oral contraceptives to mention side effects, no systematic assessment of impact on sexuality and well-being has been carried out.
Bancroft, along with Graham, began tackling this problem in a study conducted in Scotland and the Philippines in which 150 sterilized women volunteered to take either a progestin-only pill, a combined oral contraceptive (containing both estrogen and progestin), or a placebo. The four-month study, which showed some negative effects of combined oral contraceptives on mood and sexuality, served as a springboard for the Kinsey Institute study now underway.
The current study focuses on combined oral contraceptives (COCs), which are the most widely used form of steroidal contraceptives. The researchers are using two types of COCs. Both include progestin, but one is monophasic, with the same dosage of hormones being given each day for 21 days, while the other is triphasic, with the amounts of estrogen and progestin varying in an attempt to simulate the natural menstrual cycle.
The study involves tracking at least one hundred women, and possibly a sample of three to four hundred if the institute is able to secure more funding, for a minimum of one year after they begin taking one of the two randomly assigned pills. To enable the investigators to identify changes in well-being and sexuality during the study period, baseline data on mood, menstrual cycle, premenstrual symptoms, sexual interest, frequency, enjoyment, and other factors are collected before the women begin using oral contraceptives. The women are assessed again with many of the same measures after three, six, and twelve months. The women are also asked to self-identify any changes, positive or negative, that they attribute to the pill. If women in the study discontinue use of the pill or switch to another type of pill, they are reassessed immediately.
From a subgroup of sixty women, thirty on each type of pill, a blood sample is drawn each week for a month before they begin taking the pill and again during their third month on the pill. The blood is then analyzed to determine the level of free testosterone. The women also keep daily diaries during this time rating their mood, sexual interest, and sexual activity. By comparing changes in the level of free testosterone, which is known to be lowered by oral contraceptives, with changes in sexual interest recorded in the women's daily diaries, the researchers will be able to assess whether the pill-induced decrease in the level of free testosterone corresponds with a reduction in sexual interest among the women taking the pill.
The researchers' primary goal is to identify the direct effects of combined oral contraceptives on sexuality and well-being and to determine if such effects might be predicted by characteristics of the women before they start on the pill. Secondarily, they are interested in whether these direct effects are different for the two types of pills under investigation. This data would be useful both in development of oral contraceptives with fewer negative side effects and in improvement of the counseling and information women receive when choosing a contraceptive method.
Measuring the direct effects and their potential impact on a woman's decision to continue or discontinue oral contraceptives is, however, a complex issue. Because the pill is such an effective contraceptive, "for some women, for the peace of mind with respect to pregnancy prevention, it may be worth tolerating some negative effects on mood and sexuality," Sanders says. "Other women may experience positive effects on the pill that offset negative effects. For example, a woman with a history of heavy, painful periods may have a reduction in menstrual bleeding and pain while taking the pill. Her view of the pill may remain positive even if she experiences lowered sexual interest," Sanders explains. For these reasons, some women may continue taking oral contraceptives despite experiencing negative effects on mood and sexuality, while others may discontinue the pill because of the same effects. "As we investigate these patterns for each of the two pill types and relate the patterns to the characteristics and attitudes of the women measured before they started taking the pill, we may discover predictive factors that suggest the best pill type for a woman with specific patterns," Sanders states. To fully understand these patterns, it is important for the researchers to assess various dimensions of sexuality. "A woman may report a higher frequency of intercourse after starting the pill because she feels 'safe' from unwanted pregnancy, but at the same time she may notice that her interest in sex has declined. So a couple of simple questions about sex aren't enough," Sanders says.
The researchers also hope to establish an effective methodology for assessing the direct effects of steroidal contraceptives on well-being and sexuality that can be adapted for use in other countries. "We're working towards a model for use in cross-cultural settings," Bancroft explains. To create this model, the researchers are conducting substudies on their own methods in the oral contraceptive study. "We're taking a close look at how best to ask women questions about sexual function, and we're also establishing the reliability and validity of some of the measures we're using," Sanders says. As a next step, the investigators hope to adapt the assessment battery for cross-cultural use by enlisting help from people with expertise in cultural anthropology and semantics to ensure that the researchers are effectively measuring the same thing in a variety of cultures.
The Kinsey Institute's study on steroidal contraceptives for women is part of a larger focus on the effects of reproductive hormones on behavior. Over their careers, the researchers involved in the study have examined the relationship of sexuality and well-being to the menstrual cycle, premenstrual syndrome, menopause, lactation, and steroidal contraceptives. Such work is important to improving reproductive health, but it is important to women in other ways as well. "When you talk about women's reproductive health, sometimes women's sexuality is only seen in terms of reproduction," Sanders says. "The approach we have here is much broader. We like to think of reproductive health and aspects of the hormonebehavior relationship in the context of quality of life."
Another ongoing study in the female research program addresses the effects of fragrance on sexual arousal. Sanders, Graham, and Erick Janssen, an assistant scientist at the Kinsey Institute, are measuring changes in subjective and physiological measures of sexual arousal and mood in response to different fragrances presented in conjunction with erotic stimuli, with assessments at two different phases of the menstrual cycle. "There is some literature suggesting that olfactory sensitivity varies during the menstrual cycle," Sanders explains. "But our question is more specific: Will we pick up cycle effects in terms of subjective ratings of mood and physiological measures of arousal under different fragrance conditions?" Sanders notes that the researchers believe that "if there is an effect, it is probably because the fragrance is altering mood, which is why we have included measurement of mood in the study."
Besides addressing this question, the fragrance study will allow the researchers to establish the methods for looking at subjective and physiological arousal during the menstrual cycle. This will lead to a study Bancroft and Sanders are planning on normal variation in sexual interest, enjoyment, and behavior across the menstrual cycle. The fragrance study is also a testing ground for methods to study the effects of putative pheromones on women's sexual arousal, an area in which Sanders and Graham share an interest.
The female research program at the Kinsey Institute exemplifies the institute's commitment to interdisciplinary research. In all ongoing research within the program, both hormonal mechanisms and culturally sensitive psychological effects have to be taken into account. Ultimately, the female research program supports the institute's fundamental goal of expanding knowledge of human sexuality, knowledge that is valuable to many disciplines. "To me," Sanders says, "sexuality is such a key part of people's being, even in ways that people don't think of as sexuality. I think of sexuality very broadly. I think of it in terms of not only sexual interest and activity and response, but in terms of our sense of gender and self. I think it pervades just about every aspect of our functioning."