Table 2.
Prevalence of Birth Outcomes by Self-Reported Electronic Cigarette Use, Overall and by Combustible Cigarette Smoking Use During Pregnancy, PRAMS (Pregnancy Risk Assessment Monitoring System), 37 States and New York City,* 2016–2018 (Unweighted N=79,176)
| Preterm Birth (Unweighted n=11,576) |
|||
|---|---|---|---|
| E-Cigarette Use | Unweighted n | Adjusted Weighted Prevalence (95% CI)† | Adjusted PR (95% CI)† |
| Overall (unweighted N=79,176) | |||
| E-cigarette use before pregnancy‡ | 373 | 7.4 (6.2–8.8) | 0.97 (0.81–1.17) |
| E-cigarette use during pregnancy‡ | 205 | 8.3 (6.4–10.6) | 1.09 (0.85–1.40) |
| Nonuse of e-cigarettes‡ | 10,998 | 7.6 (7.4–7.8) | Ref |
| Among those who smoked combustible cigarettes during pregnancy§ (unweighted n=6,920) | |||
| E-cigarette use before pregnancy‡ | 132 | 11.9 (8.6–16.3) | 1.10 (0.79–1.54) |
| Dual use‡ | 132 | 8.8 (6.5–12.0) | 0.82 (0.59–1.14) |
| Nonuse of e-cigarettes‡ | 1,203 | 10.8 (9.8–11.9) | Ref |
| Among those who did not smoke combustible cigarettes during pregnancy§ (unweighted n=72,256) | |||
| E-cigarette use before pregnancy‡ | 241 | 6.5 (5.3–8.0) | 0.89 (0.72–1.10) |
| E-cigarette use during pregnancy‡ | 73 | 12.4 (8.7–17.3) | 1.69 (1.20–2.39) |
| Nonuse of e-cigarettes‡ | 9,795 | 7.3 (7.1–7.6) | Ref |
E-cigarette, electronic cigarette; SGA, small for gestational age; LBW, low birth weight; PR, prevalence ratio; Ref, reference. Bold indicates P<.05.
Participating PRAMS sites are outlined in Appendix 6 (http://links.lww.com/AOG/C338).
Adjusted weighted prevalence, adjusted prevalence ratios, and corresponding 95% CIs were estimated based on average predicted marginal values derived from multivariable logistic regression models controlling for maternal age, race–ethnicity, education, adequacy of prenatal care (based on the Adequacy of Prenatal Care Utilization Index), use of WIC (Special Supplemental Nutrition Program for Women, Infants and Children), combustible cigarette use during pregnancy and multivitamin use.
Electronic cigarette use before pregnancy was defined as self-reported use of electronic cigarettes during the 3 months before pregnancy but not during the last 3 months of pregnancy. Electronic cigarette use during pregnancy was defined as any self-reported use of electronic cigarettes during the last 3 months of pregnancy. Nonuse of e-cigarettes was defined as no e-cigarette use in the 3 months before pregnancy or during the last 3 months of pregnancy.
Combustible cigarette smoking was defined as self-reported smoking of combustible cigarettes during the last 3 months of pregnancy. Dual use was defined as self-reported any use of e-cigarettes and smoking combustible cigarettes during the last 3 months of pregnancy; e-cigarette–only use was defined as any self-reported use of e-cigarettes but no use of combustible cigarettes during the last 3 months of pregnancy.