Prenatal Risk factors and environmental exposure associated with early childhood wheezing in the Mother and Child in the Environment (MACE) Birth Cohort

Abstract

OPS 35: Health effects of indoor air pollution in LMIC countries, Room 411, Floor 4, August 27, 2019, 1:30 PM - 3:00 PM Background. Prenatal and environmental exposure are contributing risk factors for development of a wheezing in early childhood. Aim. To identify maternal and environmental risk factors associated with wheezing in children aged birth to 24 months in the MACE cohort. Method. The Mother and Child in the Environment (MACE) cohort includes pregnant females selected from the public sector ante-natal clinics in Durban (South Africa) (n=1140), with similar socio-economic profiles. Maternal questionnaires were administered during pregnancy and with child clinical follow-up done at 6months, 12months and 24months. Land use regression modelling was used to describe home address measures of antenatal exposure to nitrogen dioxide (NO2). Results. The mean maternal age at delivery was 25.92 (SD=5.96). The sample included exposure to HIV (n=37 (35.6%)), low birth weight (n=12 (11.0%)), pre-term birth (n= 8 (7.3%)), exposed to passive smoking (n= 77 (70.6%)) and a family history of asthma (n=40 (36.7%)). Of the children two years and younger, 466 infants had at least one follow-up visit in the first 24 months of life. Of these, 109 (23%) caregivers reported at least one incident of childhood wheeze during this period with the most number of wheeze episodes (n=63) reported at the 12 month visit. Infants exposed to passive smoking (AOR: 1.737, 95% CI: 1.073-2.811) and infants with a family history of asthma (AOR: 2.724, 95% CI: 1.650-4.496) were at an increased risk of wheezing. Ambient exposure to NO2 was not associated with wheezing infants (AOR: 0.849, 95% CI: 0.053-1.360). Conclusion. Exposure to passive smoking and a family history of asthma were risk factors associated with wheezing in children from birth to 24 months in our cohort. The absence of association with NO2 exposure could be explained by the misclassification of wheeze as reported by mothers/caregivers, particularly in the presence of upper respiratory tract infection in early childhood.