Primary Prevention in Infants of Mothers Who Have Asthma
Prenatal Intervention with First-degree Relatives who have Diagnosed Asthma
Chan-Yeung M, Manfreda J, Dimich-Ward H, Ferguson A, Watson W, Becker A. A randomized controlled study on the effectiveness of a multifaceted intervention program in the primary prevention of asthma in high-risk infants. Archives of Pediatric Adolescent Medicine 2000;54:657-63
The intervention was conducted in Vancouver, British Columbia and Winnipeg, Manitoba and included a) women registered to give birth at a community-based maternity hospital, and b) women attending university-based antenatal clinics in offices of obstetricians.
The intervention targeted pregnant women identified in prenatal clinics who would be mothers of infants determined to be at high-risk for asthma. Infants are defined as persons from birth through 1 year of age. High-risk infants are defined as those with at least one first-degree relative with asthma or two first-degree relatives with other IgE-mediated allergic disease.
The objective of this study was to determine the effectiveness of a multifaceted intervention program in the primary prevention of asthma in high-risk infants. The program included the following strategies: avoiding of house dust mites (HDMs), pet allergens, and environmental tobacco smoke; encouraging breastfeeding and supplementation with partially hydrolyzed formula; and avoiding foods that sensitize. After completing the baseline assessment, the intervention group participants were given instruction regarding steps to reduce exposure to HDMs; in addition, they were advised to remove pets from the home and to eliminate exposure to environmental tobacco smoke. Mothers were advised either to breast feed for at least 4 months or use partially hydrolyzed formula and avoid eating certain foods.
The study was a randomized controlled trial. Home visits were conducted before the birth of the infant and at 2 weeks and 4, 8, and 12 months after birth. Homes were assessed using a questionnaire and a walk-through survey. During each visit, data were collected regarding evidence within the home of leaks resulting in water damage and mildew and molds. The type of heating/air conditioning system functioning within the home was also documented. During further home visits, a questionnaire addressing the infant’s health and environment was administered.
The study participants included 251 infants in the intervention group and 242 infants in the control group.
Outcome measures were probable or possible asthma, rhinitis without apparent colds, and skin test results positive for common inhalant allergens. Thirty-eight (15.1%) of the 251 infants assessed in the intervention group met the criteria for possible or probable asthma; 49 (20.2%) of the control-group infants met the same criteria. In the intervention group, 16.7% of the infants, and in the control group, 27.3% of the infants developed rhinitis without colds, a modest but statistically significant difference. Incidence of skin test results positive to one or more inhalant allergens was similar in both groups (4.4% in the intervention group and 4.6% in the control group).
Availability of Protocol/Materials:
The protocol and materials are not available for widespread distribution.