Hormones used for contraception can effect migraine in the same way as a woman’s own hormones. Because different types of contraception work in different ways, each can have different effects on migraine. Understanding how each method works can help you make the best choice for contraception, sometimes even with benefit for migraine.
There are two main types of contraception: hormonal and non-hormonal. Hormonal methods include combined hormonal contraceptives, which contain a combination of oestrogen and progestogen. These are usually taken for 21 consecutive days before a 7-day hormone-free interval. During the break a withdrawal bleed (like a period) will occur. They are very effective methods of contraception as their main effect is to stop ovulation (the release of an egg from the ovaries) each month. Combined hormonal contraception (CHC) is very safe for most women, including most women with migraine. It is not suitable for women who are at a higher background risk of blood clots including those who smoke, have high blood pressure, are very overweight or who have migraine aura, since the oestrogen component can further increase the risk.
Other hormonal methods contain only progestogen and are usually suitable for women who are unable to, or do not wish to take oestrogens. The most effective methods work in the same way as the combined hormonal contraceptives, inhibiting ovulation, but without the oestrogen. These include:
ā The implant, which lasts for three years;
ā The injection, which lasts for three months at a time;
ā The progestigen-only pill (POP) which is taken every day without a break and contains the progestogen desogestrel.
ā The levonorgestrel intra-uterine system, which is inserted into the neckof the womb, slowly releasing progestogen into the lining of the womb over its lifespan (3 or 5 years). This keeps the lining of the womb thin so that periods can be light or even absent. The normal hormone cycle continues as ovulation is not inhibited.
The progestogen-only or ‘mini’ pill does not reliably inhibit ovulation but helps the mucous secretions from the cervix stay thick and impenetrable to sperm. Menstrual cycles can be erratic, although a few women find that their periods stop completely.
The copper intra-uterine device remains a highly effective, non-hormonal method of contraception. However, it can cause increased and prolonged menstrual bleeding, which may be associated with migraine.
Sterilisation, condoms, caps (diaphragms) and natural family planning methods have little effect on the normal hormonal cycle and therefore their use is not associated with any change in the pattern of migraine.
Headache is a common symptom during the early months of using hormonal contraception but usually resolves with time. If attacks occur, they tend to come during the hormone-free week. Some women, usually those with aura, note a worsening in frequency or severity of attacks. A few women develop aura for the first time.
For the majority of women CHCs are highly effective and safe methods of contraception. There can be some added health benefits such as reduced risk of womb, ovarian and bowel cancers, lighter menstrual periods and relief from premenstrual symptoms. Some women even take CHCs to help treat menstrual migraine. However, for a minority of women, including those who have migraine with aura, CHCs are associated with an increase in the risk of stroke. Fortunately, the actual likelihood of a stroke occurring in a young women with migraine with aura who takes the ‘pill’ is extremely low. It is also an avoidable risk since most contraceptives that do not contain oestrogen are at least as effective as CHCs and some are more effective.
So how great is the risk? Imagine a group of 100,000 women, all under 35, who do not have migraine and who don’t take CHCs. Only around one of those women is likely to have an ischaemic stroke within the next year. If the same group of women started on CHCs, of them are at risk of an ischaemic stroke within the next year. If all 100,000 women had migraine with aura and took CHCs, around 28 would be at risk. The risk of having a stroke is low even if you have migraine and take the pill and is likely to be even lower if you do not smoke or have high blood pressure. However, as the risk is directly related to the oestrogen in the CHCs, it can be avoided by using non-oestrogen methods of contraception.
The World Health Organization have made recommendations to ensure safe prescribing of CHCs by identifying women at risk of arterial thrombosis and, where the risks outweigh the benefit of the method, offering alternative contraception. Due to the increasing choice of methods available, there should be no loss of contraceptive efficacy. A history of aura at any time, even if it occurred during childhood, has been deemed an unacceptable risk factor for the development of a stroke and so women with this should not use CHC’s for contraception.
Migraine with aura accounts for 20-30% of migraines, and in 1% of cases there is no headache. The symptoms of aura are usually visual, developing gradually over 5 to 20 minutes and lasting for less than 1 hour before disappearing. People usually describe the visual aura as starting from a small, just off-centre bright spot, which enlarges to a bright, curved, zig-zag line (scintillation). The scintillations make map-like “fortification” figures that flicker with the brilliant intensity of a fluorescent bulb. Within these lines, vision can be dark and blank (scotoma). Sensory symptoms, such as feeling ‘pins and needles’ spreading up the arm from one hand and into the mouth, and difficulty saying the right words can also occur.
After the aura subsides, a typical migraine headache ensues, although sometimes the headache that follows is not a migraine-type headache or there may be no headache.
The crucial characteristics of aura are the duration and timing of symptoms in relation to onset of migraine headache. Aura should not be confused with the more common premonitory symptoms that occur 1 or 2 days before a migraine attack.
If you’re not sure whether your warning symptoms are aura, ask yourself the following questions:
Do you ever have visual disturbances:
ā Starting before the headache?
ā Lasting up to one hour?
ā Resolving before the headache?
If you answer ‘yes’ to all three questions, it is likely that your symptoms are aura.
Migraine occurring exclusively in the hormone free week is probably triggered by falling levels of oestrogen. These tend to be migraine without aura and usually commence a couple of days after the hormones are stopped. If acute treatment is inadequate to control symptoms, hormonal tretments may help.
For the majority of women with migraine who are using hormonal contraception, management does not differ from standard treatment recommendations. This means treating attacks with pain-killers and keeping diary cards to establish the pattern of attacks and to identify non-hormonal triggers. Often effective acute treatment is usually all that is necessary, particularly if attacks only occur once or twice a month.
If pain-killers are not effective, your doctor can prescribe a number of different treatments including anti-sickness drugs that help the painkillers to work more effectively, non-steroidal anti-inflammatory painkillers and triptans.
If acute treatment is inadequate to control symptoms, hormonal prophylaxis may be considered. Although there are no data from clinical trials to support the following suggestions, they are widely used in practice.
Changing the way you take your pill. There are two options which can be used separately or in combination.
ā The “tri-cycle” regimen where three consecutive hormone cycles are taken (without the traditional 7-day “break”) followed by a hormone-free interval. This means that you would have only five such migraines a year instead of thirteen. In some countries CHC pills are licensed for a 91-day cycle of 84 days of pill-taking followed by a 7-day break, resulting in only 4 pill-free intervals a year.
ā The 4-day “break” where instead of taking 21 days of the pill followed by a 7-day withdrawal period, you break the cycle for 4 days. This has been shown in trials to reduce the fall in oestrogen levels and can lessen the likelihood of a menstrual migraine from occuring.
Using natural oestrogen supplements during the hormone-free interval is another option. This provides some protection against oestrogen withdrawal, while enabling a progestogen withdrawal bleed to occur. Types of oestrogen available include 100 μg patches twice within the hormone-free week, 1.5 mg gel daily, or 2 mg oral oestradiol valerate daily during the pill-free interval.
ā Combined hormonal contraceptives (the ‘Pill’ and the ‘Patch’) are safe for healthy non-smoking women with migraine without aura
ā Combined hormonal contraceptives are contraindicated for women with migraine with aura because of an increased risk of ischaemic stroke.
ā Progestogen-only and non-hormonal methods of contraception are not associated with an increased risk of ischaemic stroke.
ā Some progestogen-only and non-hormonal methods are more effective contraceptives than combined hormonal contraceptives.
This information is provided as a general guide only and is not a comprehensive overview of prescribing information. If you have any queries or concerns about your headaches or medications please discuss them with your GP or a doctor at the National Migraine Centre.