Table 2.
Association between vaccination against pandemic A/H1N1 2009 influenza in pregnancy and risk of fetal death in nationwide cohort of 54 585 pregnancies in Denmark
| Outcome | No of women | Fetal years at risk | No of events | Hazard ratio (95% CI) | ||
|---|---|---|---|---|---|---|
| Unadjusted | Adjusted* | |||||
| Fetal death: | ||||||
| Unvaccinated | 47 523 | 19 578 | 1785 | 1 (reference) | 1 (reference) | |
| Vaccinated | 7062 | 1758 | 27 | 0.82 (0.55 to1.20) | 0.79 (0.53 to 1.16) | |
| Spontaneous abortion: | ||||||
| Unvaccinated | 32 672 | 6835 | 1649 | 1 (reference) | 1 (reference) | |
| Vaccinated | 2736 | 211 | 20 | 1.16 (0.74 to 1.80) | 1.11 (0.71 to 1.73) | |
| Stillbirth: | ||||||
| Unvaccinated | 43 663 | 12 728 | 131 | 1 (reference) | 1 (reference) | |
| Vaccinated | 7014 | 1547 | 7 | 0.43 (0.20 to 0.92) | 0.44 (0.20 to 0.94) | |
*Adjusted for propensity scores.