Early-term Birth is a Risk Factor for Wheezing in Childhood: A Cross-sectional Population Study

This cross-sectional population-based study of children examined the association between gestational age at birth and the risk of respiratory illness, hospital admissions and other health related outcomes in the first 10 years of life. Participants included 13,361 preterm-born children and 13,361 term-born matched control subjects. Respiratory and neurological health was measured via a parent-completed questionnaire and hospital database records. Gestational age at birth was used to categorize the children into early-term (37-38 weeks’ gestation) and full-term (39-42 weeks’ gestation) categories. The gestational age was based on maternal reporting of the last menstrual period and antenatal ultrasound scans. 

 The results of this particular study revealed early term-born children had a significantly higher rate of caesarean section (CS) delivery, particularly those delivered by means of elective CS, compared to the full term-born control subjects. Of the children less than 5 years of age, the prevalence of wheeze, use of inhaler medication and hospital admission in first year of life were higher in the early term-born children than the full-term born control. Of the children aged 5 years and older, there was a higher prevalence in the pre term-born than full term-born subjects in wheezing, recent wheeze, doctor’s diagnosis of asthma, exercise induced asthma, chest infection over the last year, admissions to the neonatal unit in the first 28 days of life and admissions to the hospital in the first year of life. There were no statistically significant findings relating to the difference between children delivered by means of CS compared with those delivered by means of vaginal delivery (VD) for respiratory symptoms throughout childhood. However, early term–born or full term–born infants delivered by means of CS were associated with greater admissions to the neonatal unit when compared with those born early term or full term and delivered by means of VD. The children born early term by means of CS or VD had higher rates of wheezing compared with children born full term by means of VD and marginally increased rates for children born early term by means of CS compared with children born full term by means of CS.

This paper suggests that respiratory symptoms continue into early school years for early term–born children when compared with full term–born children and that these children are receiving increased treatment. The data demonstrated that early term–born children have more wheezing than full term–born control subjects. The authors suggested the possible mechanisms underlying these recurrent respiratory symptoms in children born early term might be related to delivery at a marginally earlier stage of lung growth and development when surfactant production might not be optimal.

Edwards, M.O., Kotecha, S.J., Lowe, J., Richards, L., Watkins, W.J., & Kotecha, S. (2015). Early-term birth is a risk factor for wheezing in childhood: A cross-sectional population study. 136(3), 581-587. doi: 10.1016/j.jaci.2015.05.005.