Risk factors for early wheezing in preterm infants: a retrospective cohort study

Abstract Background: The factors that cause recurrent wheezing in children are complex, and premature delivery may be one of these factors. Little is known about early wheezing in preterm infants.Methods: Data were sourced from 1616 children born between 2007 and 2013 from 8 hospitals in Guangxi, China. All children were followed up by telephone or questionnaire through the sixth year of life. Children were grouped by gestational age (GA): Group A, GA ≤ 32 weeks; Group B, 32 weeks < GA < 37 weeks; and Group C, 37 weeks ≤ GA < 42 weeks.Results: The incidences and risk factors for early wheezing in preterm infants were analysed. The incidences of early wheezing were as follows: Group A > Group B > Group C. The incidence of persistent early wheezing in Group A or Group B was significantly higher than that in Group C, respectively. SGA (95% CI: 1.097 to 7.519) was a risk factor for early wheezing in group A. Male sex (95% CI: 1.595 to 4.501) and family history of allergies (95% CI: 1.207 to 3.352) were risk factors for early wheezing in group B.Conclusions: 1. New-borns with younger GAs had a higher risk of early wheezing. 2. The incidence of persistent early wheezing for preterm infants (GA ≤ 32 weeks and 32 weeks < GA < 37 weeks) was higher than that for full-term infants (37 weeks ≤ GA < 42 weeks). 3. SGA was a risk factor for early wheezing in preterm infants with a GA ≤ 32 weeks. 4. Male sex, personal history of allergies and family history of allergies were all possible factors affecting early wheezing in preterm infants with a GA > 32 weeks but < 37 weeks and full-term infants. Among them, male sex and family history of allergies were risk factors for early wheezing. 5. Mode of delivery, passive smoking, breastfeeding and invasive mechanical ventilation were not possible risk factors for early wheezing in infants of different GAs.