Table 3 Animal studies on the effects of prenatal e-cigarette exposure on birth parameters.
| Author, year (region) | Study type | N | Active substance | Period of exposure | Measurement timing | Measurements | Outcomes |
|---|---|---|---|---|---|---|---|
| PN = postnatal day; DP = day of pregnancy; TC = traditional cigarettes; n. s.= not specified | |||||||
| Church et al., 2020 (USA) | Animal study (mice) | 135 pups | E-liquid with and without nicotine (16 mg/mL) | Fertilisation to DP 17 | PN day 21, 56 and 84 | Effects on birth parameters | No effects on litter size and birth weight |
| Nguyen et al., 2019 (Australia) | Animal study (mice) | 24 mothers | Tobacco-flavoured e-liquid with 18 mg/mL nicotine | TC9 weeks before fertilisation, e-liquid until PN day 20 | PN day 1, 20, 84 and 91 | Effects on birth parameters | No effects on litter size, survivability. Reduced birth weight. |
| Nöel et al., 2020 (USA) | Animal study (mice) | 183 pups | Cinnamon-flavoured e-liquid with 36 mg/mL nicotine | Group A:12 days before fertilisation until DP 19 of Group B: Fertilisation until DP 19 | PN day 1 und 28 | Effects on birth parameters | no effect on litter size, +Nic e-liquid resulted in reduced body size and birth weight |
| Sifat et al., 2020 (USA) | Animal study (mice) | 121 pups | E-liquid with 24 mg/mL nicotine | DP 5 to PN day 7 | PN day 8 – 9 and 40 – 45 | Effects on birth parameters | no effect on litter size, +Nic e-liquid resulted in reduced birth weight |
| Palpant et al., 2015 (USA) | Animal study (zebrafish) | n. s. | +Nic e-liquid | 3 days prenatal | PN day 1 – 3 | Effects on birth parameters | +Nic e-liquid reduced neonatal survivability |
| Nguyen et al., 2018 (Australia) | Animal study (mice) | 24 mothers | E-liquid with and without nicotine (18 mg/mL) | 6 weeks before fertilisation until PN day 20 | PN day 1, 20 and 84 | Effects on birth parameters | E-cigarette vaping without effects on weight and mortality |
| Chen et al., 2017 (Australia) | Animal study (mice) | n. s. | E-liquid with and without nicotine (18 mg/mL) | 6 weeks before fertilisation until PN day 20 | PN day 1, 20, 91 | Effects on birth parameters | No effects on birth weight and organ weight, change in fat distribution. |
| Chen et al., 2018 (Australia) | Animal study (mice) | 8 mothers | Tobacco flavoured e-liquid with and without nicotine (18 mg/mL) | 6 weeks before fertilisation until PN day 20 | PN day 20 | Effects on birth parameters | Change in fat distribution, no change in birth weight |
| Lauterstein et al., 2016 (USA) | Animal study (mice) | 36 pups | E-liquid with and without nicotine (13 – 16 mg/mL) | Fertilisation to PN day 25 – 27 | PN day 25 – 31 | Effects on birth parameters | No effects of e-cigarette vaping were observed. |
| Li et al., 2019 (Australia) | Animal study (mice) | 143 pups | E-liquid with and without nicotine (18 mg/mL) | Group A: E-liquid 6 weeks before fertilisation until PN day 20 Group B: TC6 weeks before fertilisation, then e-liquid until PN day 20 |
PN day 1, PN day 20 | Effects on birth parameters | E-liquid resulted in lowered birth weight and no changes in renal weight. |
| Smith et al., 2015 (USA) | Animal study (mice) | 28 pups | E-liquid with and without nicotine (24 mg/mL) | DP 15 – 19 and PN day 2 – 16 | PN day 98 | Effects on birth parameters | Lower birth weight (− Nic e-liquid < +Nic e-liquid < control group) |
| Orbazal et al., 2019 (USA) | Animal study (mice) | n. s. | E-liquid with and without nicotine (100 mg/mL) | ST 5 – PN10 | PN day 10 | Effects on birth parameters | Lowered birth weight and smaller size with +Nic e-liquid |