TY - JOUR

T1 - Neonatal FeNO, risk factors, and respiratory morbidity in infants

T2 - A cohort study

AU - Goth, Fanny E. M.

AU - Schmidt, Birgitte J.

AU - Green, Kent

AU - Jensen, Andreas K.

AU - Agertoft, Lone

AU - Jørgensen, Inger M.

PY - 2021

Y1 - 2021

N2 - Background Respiratory symptoms in infancy are more common in premature infants. Nitric oxide (NO) is involved in prenatal and neonatal lung development. Measurement of exhaled NO is easy and well-tolerated by neonates. We investigated whether neonatal exhaled NO can be used to predict subsequent respiratory symptoms. Furthermore, we sought to determine prenatal and postnatal factors associated with increased respiratory symptom risk during the first year of life in premature and mature infants. Methods Tidal fractional exhaled NO (FeNO) was measured in a birth cohort (n = 135) of premature and mature infants, up to six times during the first month of life. Primary outcomes were troublesome respiratory symptoms (TRS) and doctor-diagnosed asthmatic bronchitis (AB) at 1 year of age. Findings The correlation between FeNO and TRS changed significantly in an age-dependent pattern in moderately premature infants (p = .02). Moderately premature infants with a low FeNO of 2 ppb on postnatal Day 3 had a 48% (95% confidence interval [CI]: 17%-80%) probability of TRS, compared with a probability of 12% (95% CI: 1%-64%) for otherwise similar infants with a FeNO of 11 ppb. Respiratory syncytial virus infection and parental smoking significantly increased the TRS risk in premature infants. Parental asthma and maternal antibiotic use during pregnancy significantly increased the TRS risk in mature infants. Interpretation An age-specific association between neonatal FeNO and respiratory symptoms was seen in moderately premature infants. TRS risk was associated with postnatal factors in premature and prenatal factors in mature infants.

AB - Background Respiratory symptoms in infancy are more common in premature infants. Nitric oxide (NO) is involved in prenatal and neonatal lung development. Measurement of exhaled NO is easy and well-tolerated by neonates. We investigated whether neonatal exhaled NO can be used to predict subsequent respiratory symptoms. Furthermore, we sought to determine prenatal and postnatal factors associated with increased respiratory symptom risk during the first year of life in premature and mature infants. Methods Tidal fractional exhaled NO (FeNO) was measured in a birth cohort (n = 135) of premature and mature infants, up to six times during the first month of life. Primary outcomes were troublesome respiratory symptoms (TRS) and doctor-diagnosed asthmatic bronchitis (AB) at 1 year of age. Findings The correlation between FeNO and TRS changed significantly in an age-dependent pattern in moderately premature infants (p = .02). Moderately premature infants with a low FeNO of 2 ppb on postnatal Day 3 had a 48% (95% confidence interval [CI]: 17%-80%) probability of TRS, compared with a probability of 12% (95% CI: 1%-64%) for otherwise similar infants with a FeNO of 11 ppb. Respiratory syncytial virus infection and parental smoking significantly increased the TRS risk in premature infants. Parental asthma and maternal antibiotic use during pregnancy significantly increased the TRS risk in mature infants. Interpretation An age-specific association between neonatal FeNO and respiratory symptoms was seen in moderately premature infants. TRS risk was associated with postnatal factors in premature and prenatal factors in mature infants.

KW - biomarkers

KW - infant

KW - nitric oxide

KW - premature

KW - respiratory system

KW - EXHALED NITRIC-OXIDE

KW - MODERATELY PRETERM

KW - CHILDHOOD ASTHMA

KW - RSV INFECTION

KW - CHILDREN

KW - HEALTH

KW - AGE

U2 - 10.1002/ppul.25585

DO - 10.1002/ppul.25585

M3 - Journal article

C2 - 34320687

VL - 56

SP - 3174

EP - 3182

JO - Pediatric pulmonology. Supplement

JF - Pediatric pulmonology. Supplement

SN - 1054-187X

IS - 10

ER -