Children's Respiratory and Environmental Workgroup

The environment during the prenatal period and in early life is a major contributor to the
risk of developing childhood asthma. Birth cohort studies from single research centers have
identified several factors that affect the risk for developing childhood asthma, including
being exposed in early life to allergens, pollutants, viruses and bacteria, and psychosocial
stress. Despite such advances, further progress in understanding the root causes of asthma
have been hampered by the small size of previous studies, which makes it difficult to: 1)
identify asthma risk factors with certainty, 2) know how environmental factors across the
United States (U.S.) affect asthma, and 3) whether there are critical ages when pregnant
mothers, infants and young children are particularly susceptible to these influences.
Furthermore, different research groups tend to use different methods to study asthma, making
it difficult to either compare or pool findings. One other challenge is that there are
several types (i.e. phenotypes, endotypes) of childhood asthma, but these are poorly
understood. To help overcome these challenges, investigators leading 12 asthma birth cohorts
across the U.S. have established the Children's Respiratory Research Workgroup (CREW)
consortium. CREW proposes to identify specific types of childhood asthma, develop an
understanding of what early life environmental influences cause these different types of
asthma and when, and identify targets for future efforts aimed at preventing childhood
asthma.