McEvoy, Cindy T.Shorey-Kendrick, Lyndsey E.Milner, KristinSchilling, DianeTiller, ChristinaVuylsteke, BrittanyScherman, AshleyJackson, KeithHaas, David M.Harris, JuliaSchuff, RobertPark, Byung S.Vu, AnnetteKraemer, Dale F.Mitchell, JulieMetz, JillGonzales, DavidBunten, CarolSpindel, Eliot R.Tepp, Robert S.Morris, Cynthia D.2020-07-302020-07-302019-05-01McEvoy, C. T., Shorey-Kendrick, L. E., Milner, K., Schilling, D., Tiller, C., Vuylsteke, B., Scherman, A., Jackson, K., Haas, D. M., Harris, J., Schuff, R., Park, B. S., Vu, A., Kraemer, D. F., Mitchell, J., Metz, J., Gonzales, D., Bunten, C., Spindel, E. R., Tepper, R. S., … Morris, C. D. (2019). Oral Vitamin C (500 mg/d) to Pregnant Smokers Improves Infant Airway Function at 3 Months (VCSIP). A Randomized Trial. American journal of respiratory and critical care medicine, 199(9), 1139–1147. https://doi.org/10.1164/rccm.201805-1011OChttps://hdl.handle.net/1805/23449Rationale: We reported a randomized trial demonstrating daily supplemental vitamin C to pregnant smokers significantly improved newborn pulmonary function tests. The current study tests these results in a new cohort using infant pulmonary function tests. Objectives: To determine if infants of pregnant smokers randomized to daily supplemental vitamin C would have improved forced expiratory flows (FEFs) at 3 months of age compared with those randomized to placebo, and to investigate the association of the α5 nicotinic acetylcholine receptor. Methods: A randomized, double-blind, placebo-controlled trial was conducted at three centers. Two hundred fifty-one pregnant smokers were randomized at 13-23 weeks of gestation: 125 randomized to vitamin C (500 mg/d) and 126 to placebo. Measurements and Main Results: The primary outcome was FEF75 at 3 months of age performed with the raised volume rapid thoracic compression technique (Jaeger/Viasys). FEF50 and FEF25-75 obtained from the same expiratory curves were prespecified secondary outcomes. The infants of pregnant smokers randomized to vitamin C (n = 113) had the following FEFs at 3 months of age compared with those randomized to placebo (n = 109) as measured by FEF75 (200.7 vs. 188.7 ml/s; adjusted 95% confidence interval [CI] for difference, -3.33 to 35.64; P = 0.10), FEF50 (436.7 vs. 408.5 ml/s; adjusted 95% CI for difference, 6.10-61.30; P = 0.02), and FEF25-75 (387.4 vs. 365.8 ml/s; adjusted 95% CI for difference, 0.92-55.34; P = 0.04). Infant FEFs seemed to be negatively associated with the maternal risk alleles for the α5 nicotinic acetylcholine receptor (rs16969968). Conclusions: Although the primary outcome of FEF75 was not improved after vitamin C supplementation to pregnant smokers, the predetermined secondary outcomes FEF50 and FEF25-75 were significantly improved. These results extend our previous findings and demonstrate improved airway function (FEF50 and FEF25-75) at 3 months of age in infants after vitamin C supplementation to pregnant smokers.en-USPublisher PolicyInfant pulmonary functionForced expiratory flowsSmoking in pregnancyVitamin CWheezingArticle