New York: For women with a history of migraine, estrogen levels are likely to drop more rapidly in the days just before menstruation than they do for women who do not have migraine history, finds a new study. The findings showed that the women with a migraine history had a faster rate of estrogen -- sex hormone -- decline regardless of whether they had a migraine during that cycle or not. In the two days after the peak estrogen level in the period after ovulation and before menstruation, the estrogen levels in the women with migraine dropped by 40 percent compared to 30 percent for women without migraine. The rate dropped 34 picrograms per milligram of creatinine (pg/mgCr) in women with migraine, compared to 23 pg/mgCr in women without migraine, suggesting that there's a process that links estrogen withdrawal and menstrual migraine, the researchers explained. "These results suggest that a 'two-hit' process may link estrogen withdrawal to menstrual migraine," said lead author Jelena Pavlovic from Albert Einstein College of Medicine in the US. For other hormone patterns, there were no differences between women with migraine and women who did not have migraine. “More rapid estrogen decline may make women vulnerable to common triggers for migraine attacks such as stress, lack of sleep, foods and wine,” Pavlovic added. For the study, published online in the journal Neurology, the team reviewed migraine history, daily headache diaries and hormone data for 114 women of an average 47 years, with a history of migraine and 223 women without a history of migraine. The investigators measured hormone levels from daily urine samples for one monthly cycle; the participants' peak hormone levels, average daily levels and day-to-day rates of decline were calculated over the five days following each hormone peak in their cycles. "Future studies should focus on the relationship between headaches and daily hormone changes and explore the possible underpinnings of these results," Pavlovic noted.