Duration of exclusive breastfeeding and wheezing in the first year of life: A longitudinal study.
BACKGROUND
Wheezing is the most common symptom associated with asthma in young children. There is a lack of well-designed prospective studies on the relationship of exclusive breastfeeding with wheezing in infants. This prospective cohort study investigated whether a relationship exists of exclusive breastfeeding with wheezing at 12 months of age.


METHODS
A series of 1632 mother-infant pairs were sequentially recruited. Mothers were trained at hospital on breastfeeding practices and how to recognise wheezing. At hospital discharge they received a calendar-diary to record the date at stopping breastfeeding and at onset of wheezing. Data were collected by telephone interviews through 12 months post-delivery. Breastfeeding was in accordance with the World Health Organisation and wheezing with the International Classification of Diseases (ICD-10-CM code R06.2).


RESULTS
At 12 months 1522 mother-infant pairs were participating. Breastfeeding started in 95.9% of them and was exclusive in 86.1%. The incidence of wheezing ever and recurrent wheezing at 12 months of age was 33.7% and 10.0%, respectively. Duration of exclusive breastfeeding was shorter in wheezing than non-wheezing infants (median 2.6 months vs. 4.1 months, P<0.001). After adjustment for confounders each month of exclusive breastfeeding reduced the risk of wheezing ever by 11% and of recurrent wheezing by 15%, at 12 months of age.


CONCLUSIONS
Longer duration of exclusive breastfeeding reduces the risk of wheezing throughout the first 12 months of life. These findings would be relevant to all healthcare operators and mothers, also to improve their awareness about the best feeding practices for the infant's health.
Department of Health Sciences, University of Milan, Milan, Italy; Department of Paediatrics, San Paolo Hospital, University of Milan, Milan, Italy.
Elvira
E
Verduci
Department of Paediatrics, San Paolo Hospital, University of Milan, Milan, Italy.
Giuseppe
G
Banderali
Department of Clinical and Experimental Medicine, Section of Paediatrics, University of Pisa, Pisa, Italy.
Diego
D
Peroni
Department of Health Sciences, University of Milan, Milan, Italy; Department of Paediatrics, San Paolo Hospital, University of Milan, Milan, Italy; PhD School in Nutritional Sciences, University of Milano, Milan, Italy.
Carlotta
C
Lassandro
Department of Health Sciences, University of Milan, Milan, Italy; Department of Paediatrics, San Paolo Hospital, University of Milan, Milan, Italy. Electronic address: giovanni.radaelli@unimi.it.
Giovanni
G
Radaelli
D001249:Asthma / Q000453:epidemiology* / Q000503:physiopathology; D001942:Breast Feeding / Q000706:statistics & numerical data*; D015331:Cohort Studies; D005260:Female; D006801:Humans; D007223:Infant; D007231:Infant, Newborn; D007407:Interviews as Topic; D007558:Italy / Q000453:epidemiology; D008137:Longitudinal Studies; D008297:Male; D009035:Mothers; D011446:Prospective Studies; D012135:Respiratory Sounds; D013997:Time Factors
Asthma; Breastfeeding; Exclusive breastfeeding; Infants; Recurrent wheezing; Wheezing