Menstrual cycle linked to poorer recovery from head injuries

It could be argued that some women have enough to contend with around the time of their menstrual cycle. But uncomfortable pains are just the beginning, as new research suggests that women who suffer head injuries within the 2 weeks before their period have a slower recovery time and poorer health up to 1 month after injury.

Researchers from the University of Rochester in New York say that if these findings are confirmed, they could change the treatment and prognosis of women who suffer head injuries from sports, car accidents, falls or combat.

The findings were published in the journal Head Trauma Rehabilitation.

The investigators say previous studies have suggested that women who experience head injuries have greater cognitive decline, slower reaction time, more headaches, longer periods of depression, longer hospital stays and longer delays in returning to work, compared with men.

They say that these findings are stronger in women who are of childbearing age. It has been unclear why there are such differences, but the senior author of this most recent study, Jeffrey J. Bazarian of the University of Rochester School of Medicine and Dentistry, says that female sex hormones – such as estrogen and progesterone – can play a part.

Kathleen M. Hoeger, professor of obstetrics and gynecology at the University of Rochester School of Medicine and Dentistry and co-author of the study, explains that any stressful event, including a head injury, can cause the pituitary gland in the brain – the body’s hormonal generator – to shut down.

She notes that if this gland is unable to work, this would cause the levels of estrogen and progesterone to rapidly drop.

High progesterone ’causes poorer health and recovery

To investigate the link between head injury and sex hormone levels further, the investigators recruited 144 women between the ages of 18 and 60. All of these women had experienced head injuries and arrived at various New York emergency departments within 4 hours of injury.

Within 6 hours of injury, all patients gave blood and the researchers were able to determine the phase of their menstrual cycle through progesterone levels.

The participants were then divided into three groups. There were 37 patients in a premenstrual/high progesterone group, 72 in a low progesterone group (progesterone is low in the 2 weeks after a period), and 35 were in a birth control group based on self-reported use.

After monitoring the recovery of the women for 1 month, it was found that those in the premenstrual/high progesterone group were twice as likely to have worse scores on standardized tests that measure recovery from concussion and quality of life, compared with women in the low progesterone group.

Furthermore, women in the premenstrual/high progesterone group also had the lowest scores on a health rating scale with an average of 65.

A score of 0 indicates the worst health possible, while 100 indicates the best possible health. The highest scores from this scale came from women in the birth control group, with an average of 77.

Explaining the findings, Bazarian says:

“If you get hit when progesterone is high and you experience a steep drop in the hormone, this is what makes you feel lousy and causes symptoms to linger.
But, if you are injured when progesterone is already low, a hit to the head can’t lower it any further, so there is less change in the way you feel.”

Birth control pill ‘provides benefits for athletic women

The researchers note that there was no clear difference between the group of women taking birth control pills and the group with low progesterone levels.

They say this is because women on birth control have a “constant stream” of synthetic sex hormones that “mimic” the act of progesterone, therefore they do not experience a drop in hormones as long as they are taking the pill.

Because of this and other health benefits, Hoeger says the birth control pill could be helpful for athletic women.

“Women who are very athletic get several benefits from the pill. It protects their bones and keeps their periods predictable,” she says.

“If larger studies confirm our data, this could be one more way in which the pill is helpful in athletic women, especially women who participate in sports like soccer that present lots of opportunities for head injuries.”

Last year, Medical News Today reported on a study suggesting that continuously taking birth control pills can lower pain during menstrual cycles.

Written by Honor Whiteman