Fig. 1.

Consort diagram and study design. Pregnant smokers were randomized to vitamin C or placebo at less than 23 weeks of gestation as part of a clinical trial to evaluate impact on offspring lung function. Non-smoking subjects were recruited as part of an ancillary study to perform doppler ultrasound. Placentas were collected at delivery from 210 subjects for histology and gene expression analysis. Samples with pregnancy-related complications and poor-quality control metrics were excluded from molecular analysis.