Table 4.
Odds ratios for the association between SARS-CoV-2 infection and miscarriage from multinomial logistic regression models
| Number of pregnancies | Number (%) of ongoing pregnancies | Number (%) of miscarriages | Odds ratio (95% CI)a | p-value | Adjusted odds ratio (95% CI)b | p-value | |
|---|---|---|---|---|---|---|---|
| Primary analysis (historical controls) | |||||||
| Uninfected | 9075 | 7734 (85.2%) | 600 (6.6%) | 1 | 1 | ||
| Infected | 3025 | 2426 (80.2%) | 204 (6.7%) | 1.13 (0.95–1.34) | 0.16 | 1.12 (0.94–1.34) | 0.22 |
| Supplementary analysis (contemporary controls) | |||||||
| Uninfected | 9075 | 7495 (82.6%) | 584 (6.4%) | 1 | 1 | ||
| Infected | 3025 | 2426 (80.2%) | 204 (6.7%) | 1.10 (0.93–1.30) | 0.28 | 1.00 (0.84–1.20) | 0.96 |
All analyses exclude women who received COVID-19 vaccination between 6 weeks preconception and the earliest of either: end of pregnancy or the end of the exposure period at 19 + 6 weeks gestation.
CI confidence interval.
aAdjusting for matching factors: maternal age and gestational age at the date of infection of index infected pregnancy (and season of conception for primary analysis).
bAdditionally adjusting for deprivation, urban/rural status, and clinical vulnerability (and ethnicity and season of conception in supplementary analysis).