More boys have asthma than girls. But after adolescence and puberty, things change. More women have asthma than men. Women are more likely to have asthmatic attacks that bring them to the emergency room or keep them hospitalized with a severe attack. The reasons why asthma is more common and more severe in women than in men is uncertain, but it is an area of active research at Brigham and Women's Hospital. Among the "leading suspects" are genetic differences, hormonal differences, and differences in environmental exposures leading to asthma and asthmatic exacerbations.
There are some clues out there. Some women with asthma experience worsening of their disease related to their menstrual cycle. After menopause, women who take estrogen replacement therapy are more likely to develop asthma than those who do not. And pregnancy can have a large impact on asthma, more than can be explained by the effect of an enlarging uterus compressing the bottom of the lungs. Perhaps the hormonal changes involved in these uniquely female experiences affect the biology of the airways in persons with asthma.
The home environment may also play a crucial role in gender differences in asthma. The indoor environment is recognized as an important source of allergens that lead to the development of asthma and that trigger asthmatic attacks in those with already established asthma. For women who spend more time in the home, dust mites, animal danders, molds, and cockroach antigens are potential drivers of more severe (allergic) asthma. And consider influences on the mother that may contribute to determining whether her child develops asthma: vitamin D levels, major stress, and cigarette smoke are known to be important factors. There is little doubt that the mother's health and life experiences influence the growth and development of the fetus and newborn child more than the father's.
At Brigham and Women's Hospital expert asthma care is provided by pulmonary specialists working in collaboration with allergists under the auspices of Partners Asthma Center. Pulmonary specialists with a special interest in asthma in women, working in close collaboration with our colleagues in Maternal-Fetal Medicine, are Drs. Megan Hardin, Barbara Cockrill, and Christopher Fanta.