I was going to just do one big post on this subject, but the amount of information out there is so extravagant that perhaps I'll do several. I suspect this topic doesn't get much air because well, most bloggers don't want to relate personal anecdotes. And really, there are no really good solutions to this issue.
If you are anything like me, in high school health class you were taught that things were pretty bad for women and then suddenly they invented The Pill and it freed us to enjoy sex without worry.
Like many women I was given the pill before birth control was even on my mind. Doctors routinely give it out to make menstrual cycles "more regular," fix PMS, cure acne, and for other non-birth control reasons.
This troubles me and now that I know better I would make sure that any daughter I have isn't handed the pill so casually. There are so many types of hormonal contraceptives and so many conflicting studies that it's hard to say that the pill is a bad thing. But given how little we still know about human reproduction, I'd rather not take it unless I have to. When I stopped taking it many frustratingly persistent health problems I struggled with went away.
I think because there aren't very many good alternatives for birth control, some of the problems with the pill are swept under the rug. Women deserve to know about them.
So here are some good sources I've been reading:
Some letters from a study on long-term mortality. Here are some good quotes (nulliparous means women who have never had children)
"Deaths increased three times more in “ever” takers under age 30 than in young “never” takers. GP observed “ever” takers had significant increased mortality rates compared with “never” takers for all circulatory diseases, cerebrovascular disease, other circulatory diseases (thrombosis), and violence (perhaps reflecting previously increases in mental illness and marital break ups in “ever” takers). A much vaunted ovarian cancer reduction depended on 14 deaths in “ever” takers and 29 deaths in “never” takers and 75 deaths in each group in the full data set. Whether these women were taking fertility drugs or HRT, which can increase the risk of ovarian cancer, is unknown.2,3"- Dr. Ellen Grant
"Troubling trends of increased morbidity and mortality among OC users v. non-users are also apparent when considering the subset of women who constituted a small minority of users in this study cohort, but who predominate among current users, namely, young nulliparous women."- Dr. Joel Brind
"The results of this large study are really welcome and promising to highlight long term safety of oral pills which are the most effective method of contraception and save many women's lives from complications of unwanted pregnancies-" Dr. Sharma
"It is surprising why the authors did not give greater importance to the fact that such a huge proportion of participants (one third) were lost to follow-up. Usually, a great restrain is needed when interpreting a cohort study attaining a retention rate lower than 80%."- Dr. Miguel A. Martinez-Gonzalez
"It is now surely inconceivable that any medical scientist who has some understanding of basic mechanisms could believe that widespread hormone use, especially of progesterones, is not a major health problem."- Dr. Ellen Grant
Here is among the most interesting letters:
Hannahford et al. (2010) report convincing evidence for reduction in mortality from several forms of cancer and other disease in women who have used oral contraception compared to never users. However, they also find a higher rate of violent death among ever users, and that the rate of violent death increases with longer duration of oral contraceptive use, but they are unable to explain these intriguing results. I suggest that recent evolutionary insights into human partner choice may provide a clue.
There is evidence that use of oral contraception alters women’s baseline preferences for men[2,3] such that pill users prefer men who are relatively similar to themselves at loci in the major histocompatibility complex (MHC). One consequence of being partnered with relatively MHC-similar men is that such women express lower sexual responsivity toward their long-term partner compared with women in relatively MHC-dissimilar couples, reject sexual advances from their partner more frequently, and report having had more extra-pair partners. Other evidence points to MHC- similar couples being more likely to experience problems conceiving children, and having less healthy children due to lower MHC-heterozygosity. Cumulatively, these effects could have real impact on the quality of spousal relationships[3,5].
It is not unreasonable to suspect that such effects could also influence rates of intimate partner violence. This is the most common cause of nonfatal injury among women and accounts for more than a third of women murdered in the US. Furthermore, ex-partners are a key risk factor, which could further emphasise the risk for pill users if the behavioural effects of pill use ultimately influence rates of marital breakdown[3,5].- Dr. S. Craig Roberts
As you can see there is still a bit of a debate on how exactly hormonal contraceptives impact women's long-term health. A debate I was totally unaware of when I was on them...
And more and more stuff still comes out every year showing unintended effects. An interesting, but inconclusive study last year found that hormonal contraception can change a woman's brain structure. I could definitely write separate posts on how the pill effects nutrition, future fertility, bone density, inflammation, heart disease risk, hypertension, libido, mood, and that's the tip of the iceberg. I can't promise a series, but this is a topic that definitely interests me.
Context and Variation has a good post about The Pill from an anthropological perspective.
The second health issue I want to mention is the potential increase in systemic inflammation with the use of hormonal contraceptives (one of my other undergraduates, Katherine Tribble, found this article for our lab's weekly journal club). Morin-Papunen et al (2008) looked at women at thirty one years of age in the Northern Finland Birth Cohort, born in 1966. They grouped these women into levonorgestrel-releasing intrauterine device (IUD) users, oral contraceptive users, and no hormonal contraception use. Morin-Papunen et al (2008) found oral contraceptive usage was correlated with increased C-reactive protein concentrations -- this is a biomarker for inflammation that is associated with cardiovascular disease. Compared to IUD users, oral contraceptive users also had more insulin resistance, higher blood pressure, raised lipids and insulin levels, despite having a smaller waist and lower waist-hip ratio (a larger waist or higher waist-hip ratio is often associated with these results). Further, most of these results actually strengthened when factors like BMI, household income, and alcohol consumption were controlled for. Another interesting point, third generation hormonal contraceptives, which are lower concentrations of synthetic hormones than the second generation, actually had higher serum levels of insulin, CRP, total cholesterol and other lipids, compared to users of second generation contraceptives.
Based on my own research, I think it's not a good idea to use The Pill for anything other than birth control unless all other options have been explored. As birth control it is the most effective, which leaves women who don't do well on it or who would prefer to take a precautionary approach with some tough choices. There is some evidence that non-oral methods like the Nuvaring are better, though actually there are some disturbing studies on the patch and Depo. Women in marriages/long-term relationships for whom a pregnancy wouldn't be the worst thing might want to explore fertility charting (this isn't your mom's method, significant research and improvement has been done on this method in the last decade) or withdrawal (possibly just as effective as condoms).
I think an issue is that it's considered silly to think about children in your twenties. But just because you'll change in the future doesn't mean you shouldn't think about it at all. If you are trying to live close to the species optimum as possible in the modern world, you will probably make different choices.