Associations between Smoking and Smoking Cessation during Pregnancy and Newborn Metabolite Concentrations: Findings from PRAMS and INSPIRE Birth Cohorts.

Newborn metabolite perturbations may identify potential biomarkers or mechanisms underlying adverse, smoking-related childhood health outcomes. We assessed associations between third-trimester smoking and newborn metabolite concentrations using the Tennessee Pregnancy Risk Assessment Monitoring System (PRAMS, 2009-2019) as the discovery cohort and INSPIRE (2012-2014) as the replication cohort. Children were linked to newborn screening metabolic data (33 metabolites). Third-trimester smoking was ascertained from birth certificates (PRAMS) and questionnaires (INSPIRE). Among 8600 and 1918 mother-child dyads in PRAMS and INSPIRE cohorts, 14% and 13% of women reported third-trimester smoking, respectively. Third-trimester smoking was associated with higher median concentrations of free carnitine (C0), glycine (GLY), and leucine (LEU) at birth (PRAMS: C0: adjusted fold change 1.11 [95% confidence interval (CI) 1.08, 1.14], GLY: 1.03 [95% CI 1.01, 1.04], LEU: 1.04 [95% CI 1.03, 1.06]; INSPIRE: C0: 1.08 [95% CI 1.02, 1.14], GLY: 1.05 [95% CI 1.01, 1.09], LEU: 1.05 [95% CI 1.01, 1.09]). Smoking cessation (vs. continued smoking) during pregnancy was associated with lower median metabolite concentrations, approaching levels observed in infants of non-smoking women. Findings suggest potential pathways underlying fetal metabolic programming due to in utero smoke exposure and a potential reversible relationship of cessation.

Electronic cigarette use during pregnancy and the risk of adverse birth outcomes: A cross-sectional surveillance study of the US Pregnancy Risk Assessment Monitoring System (PRAMS) population.

BACKGROUND: Research on health effects and potential harms of electronic cigarette (EC) use during pregnancy is limited. We sought to determine the risks of pregnancy EC use on pregnancy-related adverse birth outcomes and assess whether quitting ECs reduces the risks. METHODS: Women with singleton live births who participated in the US Pregnancy Risk Assessment Monitoring System (PRAMS) survey study 2016-2020 were classified into four mutually exclusive groups, by their use of ECs and combustible cigarettes (CCs) during pregnancy: non-use, EC only use, CC only use, and dual use. We determined the risk of preterm birth, low birth weight, and small-for-gestational-age (SGA) by comparing cigarette users to non-users with a modified Poisson regression model adjusting for covariates. In a subset of women who all used ECs prior to pregnancy, we determined whether quitting EC use reduces the risk of preterm birth, low birth weight, and SGA by comparing to those who continued its use. All analyses were weighted to account for the PRAMS survey design and non-response rate. RESULTS: Of the 190,707 women (weighted N = 10,202,413) included, 92.1% reported cigarette non-use, 0.5% EC only use, 6.7% CC only use, and 0.7% dual use during pregnancy. Compared with non-use, EC only use was associated with a significantly increased risk of preterm birth (adjusted risk ratio [aRR]: 1.29, 95% confidence interval [CI]: 1.00, 1.65) and low birth weight (aRR: 1.38, 95%CI: 1.09, 1.75), but not SGA (aRR: 1.04, 95%CI: 0.76, 1.44). Among 7,877 (weighted N = 422,533) women EC users, quitting use was associated with a significantly reduced risk of low birth weight (aRR: 0.76, 95%CI: 0.62, 0.94) and SGA (aRR: 0.77, 95%CI: 0.62, 0.94) compared to those who continued to use ECs during pregnancy. CONCLUSIONS: Pregnancy EC use, by itself or dual use with CC, is associated with preterm birth and low birth weight. Quitting use reduces that risk. ECs should not be considered as a safe alternative nor a viable gestational smoking cessation strategy.