The contraceptive pill catalysed a sexual revolution. Women in the 1960s were granted newfound sexual liberty by effectively making pregnancy a woman’s choice and taking away the fear of unwanted or unplanned pregnancy. This colossal shift in sexual practice and family planning triggered a religious, scientific and political backlash. However, women continued to ask for and take “the pill”; and it is now used by over 100 million women worldwide. Whilst there is a reasonable pool of information about its immediate and short-term side effects, there is considerable concern about its long term effect on fertility and other risks it may pose to health.
Does “The Pill” permanently affect fertility?
As the contraceptive pill is used to induce temporary infertility, there is understandably a concern that it may have a long-term effect on fertility. Fortunately, the pill has been around for long enough enabling large and long-term studies to have taken place. These studies refute the anecdotal accounts of delayed return to fertility, after stopping oral contraceptive use. In fact, a large European study which followed 60,000 women after stopping (combined or progestin-only) oral contraceptives, found that 20% of women were able to become pregnant in their first cycle after pill cessation. 80% of all women were able to become pregnant in the first year after pill cessation. Whilst women will be older when they stop taking an oral contraceptive, as compared to when they started taking it, and age is known to have a major impact on fertility; this study found that the data on pregnancy rates was comparable to women who had never taken an oral contraceptive. In other words, the rates of pregnancy are heavily impacted by age, irrespective of the use of oral contraception.
What about the C-word?
Cancer is another, reasonable concern – and the pill has been implicated as a risk factor for certain types of cancer. However, it is also thought to be protective against other forms of cancer.
- Breast cancer – increased risk – a large analysis of 54 studies, including over 150,000 women in 25 countries, found that taking the combined oral contraceptive pill slightly increased the relative risk of developing breast cancer (by 7%). Interestingly, this increase in relative risk subsides upon pill cessation; and effectively disappears after 10 years of stopping its use.
- Cervical cancer – increased risk – studies have found that women who use the contraceptive pill for more than 5 years, have a higher risk of developing cervical cancer. This risk declines, upon stopping use of the pill. This is because using the pill does not protect you against exposure to sexually-transmitted infections, like human papilloma virus, which is a significant risk factor for cervical cancer. Attending regular smear tests, as part of the cervical cancer screening programme, is therefore of even greater importance.
- Endometrial cancer – reduced risk – oral contraceptive use has been shown to have a significant reduction in the risk of developing endometrial cancer, with longer use of the pill conferring a greater protection against developing endometrial cancer. Indeed, this risk reduction continues even after stopping oral contraceptive use. Notably, women who have other chronic lifestyle risk factors (e.g. smoking, obesity), had the greatest risk reduction by taking the pill.
- Ovarian cancer – reduced risk – studies have found that the longer you take the pill, the more likely you are to be protected against ovarian cancer, and this protection continues for up to 30 years even after stopping taking the pill. This is especially important in women who carry the carcinogenic BRCA1 and BRCA2 mutations, whose risk of developing ovarian cancer decreased with use of the pill.
- Colorectal cancer – reduced risk – a UK study of over 46,000 women found that the lifetime risk of colorectal cancer was also reduced, if they had ever taken the oral contraceptive pill.
Are there any other life-threatening conditions?
Simply put, yes. The combined oral contraceptive pill contains oestrogen, which has been recognised a major risk factor for developing venous thrombo-embolism (i.e. blood clots which can travel around the body). These clots can cause myocardial infarction (i.e. heart attacks) when they occur in the coronary arteries, and they can cause cerebrovascular accidents (i.e. strokes) when they occur in the cerebral arteries. This risk is thought to increase with higher doses of oestrogen, and it continues throughout the duration of oral contraceptive use. A Cochrane review recommended that the combined oral contraceptive with the lowest possible dose of ethinylestradiol and good compliance should be prescribed—that is, 30 μg ethinylestradiol with levonorgestrel – as this has the lowest risk of leading to blood clots.
What happens if I take the pill back-to-back?
The Faculty of Sexual and Reproductive Healthcare suggested that whilst this may be associated with symptoms such as breakthrough bleeding and bloating, there are no concerns about the safety profile of running pill packs back-to-back. “Tricycling” (i.e. taking the pill for 9-weeks, followed by a 1-week break) has been practised for decades and is preferable for some women, although others feel more comfortable with a monthly bleed. Studies have found that the metabolic, hormonal and endometrial effects of continuous pill use, are similar to those who use the pill in cycles.
A final note
No drug is perfect. The contraceptive pill is often used in the treatment of various health conditions, such as endometriosis, polycystic ovary syndrome and acne. Whether you take it by choice or out of necessity, it would not be prescribed unless the net benefit was thought to be greater than the overall risk. Non-hormonal contraceptive methods are not without inconvenience or risk either, so it ultimately comes down to what is most acceptable to you.
