Table 3.
Fecundability Ratios According to Time-Varying Current Electronic Cigarette Use and Combustible Cigarette Smoking, Pregnancy Study Online, United States and Canada, 2017–2020
| Unadjusted | Adjusted a | |||||
|---|---|---|---|---|---|---|
| Exposure Category of Use | No. of Pregnancies | No. of Cycles | FR | 95% CI | FR | 95% CI |
| Exclusive current e-cigarette user | 61 | 424 | 0.83 | 0.64, 1.07 | 0.91 | 0.70, 1.18 |
| Exclusive current cigarette smoker | 193 | 1,265 | 0.90 | 0.78, 1.04 | 1.01 | 0.85, 1.20 |
| Dual current user of e-cigarettes and cigarettes | 25 | 200 | 0.72 | 0.47, 1.09 | 0.83 | 0.54, 1.29 |
| Noncurrent user of e-cigarettes and cigarettesb | 2,325 | 12,600 | 1.00 | Referent | 1.00 | Referent |
Abbreviations: CI, confidence interval; e-cigarette, electronic cigarette; FR, fecundability ratio.
a Adjusted for age, annual household income, education, pack-years of cigarette smoking, weekly alcohol intake, intercourse frequency, doing anything to improve conception chances, body mass index, Major Depression Inventory score, multivitamin or supplement use, healthy eating index, and parity.
b Noncurrent use includes never and former users.