187 - Maternal, Neonatal, and Childhood Factors Associated with Childhood Respiratory Impairment

Poster Number: 187
Publication Number: 187.438

Background: Late preterm birth (34-36 weeks’ gestation) is associated with an increased risk for respiratory impairment during childhood.

Objective: We sought to identify factors associated with childhood respiratory impairment among children whose mothers were enrolled in a trial because they were at imminent risk for late preterm birth.

Design/Methods: Secondary analysis of a prospective follow-up study of children aged 6 to 11 years old whose mothers participated in an antenatal steroids trial for women at risk of late preterm birth. Children were included if they were enrolled in the follow-up study and had data available for the primary outcome, childhood respiratory impairment, which was a composite that included any of the following: 1) abnormal spirometry, defined as forced expiratory volume (FEV1) < lower limit of normal (LLN), forced vital capacity (FVC) < LLN, or FEV1/FVC < LLN, with LLN defined as 5th percentile by the Global Lung Initiative; or 2) daily asthma medication use in the past year. Bivariate analyses and backwards elimination were used to determine risk factors associated with childhood respiratory impairment. Log-binomial regression was used to obtain relative risks (RR) and 95% confidence intervals (CI) for the final model.

Results: Of 1,218 children enrolled in the follow-up study, 1,194 had data available for the primary outcome. 424 (35.5%) had childhood respiratory impairment. Of the 424, 390 (32.7%) had abnormal spirometry and 62 (5.2%) used daily asthma medication in the past year. Median age at follow-up was 7 years and 84% were born < 37 weeks. Mothers of children with the primary outcome were less likely to have a college degree and private insurance and more likely to have smoked tobacco and had asthma treated with medication during pregnancy. Children with the primary outcome had lower BMIs, were younger, more likely to have undergone indicated preterm birth, to have birthweight < 10th percentile, be exposed to second-hand smoke, and less likely to have been breastfed. The final model included smoking tobacco during pregnancy (aRR 1.35, 95% CI 1.11, 1.63), maternal asthma treated with medication during pregnancy (aRR 1.35, 95% CI 1.10, 1.67), birthweight < 10th percentile (aRR 1.35, 95% CI 1.14, 1.60), and age at follow-up per 1 year increase (aRR 0.88, 95% CI 0.79, 0.97).

Conclusion(s): Smoking tobacco during pregnancy, maternal asthma treated with medication during pregnancy, and birthweight < 10th percentile were associated with a higher risk and increasing age a lower risk of childhood respiratory impairment at 6 to 11 years of age.