Migraine headaches and pregnancy
Women who tend to have migraines may find that pregnancy affects the condition for the better, or worse.
The hormonal changes during pregnancy can be a trigger for migraine for some women.
However, there can be less fluctuation in hormone levels during pregnancy, which may lead to an improvement in migraine symptoms for some women.
Pregnancy also increases levels of natural pain-killing hormones called endorphins.
Migraines, and migraine treatment, should be discussed with doctors before getting pregnant. That's because some medication may not be recommended during pregnancy, or doses may need to be changed.
Causes of migraine headaches in pregnancy
Exactly what causes migraine headaches isn't known. However migraines appear to involve changes in nerve pathways, neurochemicals and blood flow in the brain.
Researchers believe that over-excited brain cells stimulate a release of chemicals. These chemicals irritate blood vessels on the brain's surface, which causes blood vessels to swell and stimulate the pain response.
Oestrogen is thought to play a role in migraines. That's why pregnancy, menstruation and menopause often change a woman's pattern of migraine headaches.
The neurotransmitter serotonin also appears to have a key role in migraines.
Keeping track of migraine triggers with a migraine diary
Hormonal changes during pregnancy are not the only things that can trigger migraine headaches. Most women have a combination of triggers. For instance stress, missed meals and lack of sleep may all trigger a migraine. Something that triggers a migraine one day may not bother you at all the next.
Some migraines last a few hours. Others, if left untreated, can last for up to 72 hours. Migraines are quite unpredictable. So while pregnancy may make them worse for one woman, they might completely disappear for another.
A headache diary can let you keep track of your particular triggers. This will help your doctor decide what treatment will work best to relieve your specific symptoms. It may also help you recognise a pattern that tells you which triggers to avoid while you're pregnant.
Each time you have a headache write down:
- Your specific symptoms - where you feel the pain, what the pain feels like and any other symptoms such as vomiting or sensitivity to noise, smells or bright light.
- The time your headache started and ended.
- Food and drinks you had in the 24 hours before the migraine.
- Any change in your environment such as travelling to a new place, a change in weather or trying new kinds of food.
- Any treatment you tried, and whether it helped or made the headache worse.
Common food triggers include:
- Foods that contain the preservatives monosodium glutamate (MSG) and nitrates
- Aspartame or E951
Tests for migraines
Headaches can be caused by a pregnancy complication called pre- eclampsia. So your doctor may assess you for that condition before making a diagnosis of migraine. Be sure to tell your doctor about any medication you're taking, including over-the-counter products and natural supplements. Also let your doctor know if anyone in your family has had migraines.
The doctor can often diagnose migraine from a headache diary and your medical history. CT scans and other radiology tests to rule out other causes of your headaches aren't usually advised in pregnancy. That's because of the potential risks.