Migraines During Pregnancy and Menstruation
In general women who have menstrual migraine (attacks with menstruation or with the onset of menarch), do not have migraine attacks when they are pregnant.
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A fall in estrogen levels can precipitate migraine attacks, and normal, stable levels prevent them. The highest incidence of migraine attacks occurs in women during estrogen and progesterone fluctuations - during menarche, menstruation, and the use of oral contraceptives."
The incidence of menstrual migraine is as high as 60% - 70%.
Most women have attacks, usually without aura, during their period (menses), which is the time of greatest hormone fluctuation.
Interestingly, estrogens have a significant effect on magnesium balance, especially the form most associated with migraine headaches - ionic magnesium (Mg2+). High estrogen levels have been shown to lower Mg2+ levels, thus making an attack more likely". Normal, physiological levels of estrogens did not interfere with levels of Mg2+.
Low concentrations (normal levels) of progesterone raised Mg2+ levels, and hgh doses significantly lowered it, again making an attack more likely. Testosterone had no effect on magnesium levels.
Again, this emphasizes the importance of keeping one's magnesium levels normal, which is especially important in pregnant women.
If a woman starts her pregnancy with low magnesium levels, she is more likely to suffer from a worsening of her migraine and she will have a higher risk of blood-clotting disorders and derebral vasospasm, should she have an AVM or aneurysm.
Some studies have shown that magnesium supplementation also reduces the baby's risk of having a neurological birth defect.