Breastfeeding and the Risk of Wheezing Among High-Risk Infants
by Anne Eglash MD, IBCLC, FABM
Wheezing in the first year of life is stressful for infants, families, and healthcare providers. Wheezing often starts as a response to lower respiratory infections (virally-induced wheezing) and supportive care is the mainstay of treatment. Asthma medications such as steroids and albuterol often don’t help these infants, so families are stressed as they watch their infants struggle with wheezing. Their lives are disrupted for several days and sometimes weeks, while wheezing increases healthcare visits and hospitalizations.
Lower respiratory infections trigger an immune response in infants that increases the risk of wheezing with subsequent respiratory infections, especially in the first few years of life.
The question is whether breastfeeding can modify this risk because of the immune modulating and maturating factors in human milk.
According to the authors of a recently published systematic review and meta-analysis regarding the relationship between wheezing and breastfeeding, wheezing affects 36% of infants in Western countries. The authors sought to evaluate the effect of breastfeeding on wheezing among high-risk infants who have a family history of asthma/allergy. Previous meta-analyses and systematic reviews have not focused on high-risk infants.
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The risk of wheezing is high in infancy and is heightened in infants with a family history of asthma/atopy. The role of breastfeeding in influencing respiratory health for these high-risk infants is unclear.
To systematically appraise evidence for the association between breastfeeding and wheeze incidences and severity in high-risk infants.
Studies identified through electronic databases and reference lists were eligible if they assessed breastfeeding and respiratory outcomes in infants with a family history of asthma/atopy. The primary outcome was wheeze incidences in the first year of life. Secondary outcomes were wheeze incidences in the first 6 months of life, indicators of wheeze severity (recurrent wheeze, health-care utilization, and medication use), and other wheeze-related outcomes [bronchiolitis, pneumonia, croup, and incidence of lower respiratory tract infection (LRTI)] up to 12 months old. Meta-analyses were conducted where possible.
Of 1843 articles screened, 15 observational studies met the inclusion criteria. Breastfeeding was associated with 32% reduced odds of wheezing during the first year of life (ever vs. never: OR, 0.68; 95% CI: 0.53, 0.88; n = 9 studies); this association was even stronger in the first 6 months (OR, 0.45; 95% CI: 0.27, 0.75; n = 5 studies). Breastfeeding for a “longer” versus “shorter” time (approximately longer vs. shorter than 3 months) was associated with 50% reduced odds of wheezing at the age of 6 months (OR, 0.50; 95% CI: 0.39, 0.64; n = 3 studies).
Breastfeeding was associated with reduced odds of wheezing in high-risk infants, with the strongest protection in the first 6 months. More research is needed to understand the impact of breastfeeding intensity on wheezing and to examine additional respiratory outcomes, including wheeze severity. This review was registered at PROSPERO as CRD42019118631.
This is wonderful and important. Research is supposed to help guide us on what we can do clinically to not only treat illness, but to prevent it. Breastfeeding is clearly a modifiable factor for many families. When counseling prospective parents, wheezing should be considered a risk of artificial feeding, especially for parents with asthma and allergies. During well-child exams or other office visits, the lactating parent could be asked about breast/chestfeeding goals. That would provide a window of opportunity to explain the very important reduced risk of wheezing if they breastfeed for at least 3 months. There is evidence from Dr. Meghan Azad that exclusive breastfeeding for at least 6 months with addition of complementary foods and continued breastfeeding for at least a year affords even greater protection from wheezing in a dose-dependent manner.