Sibling analysis of conception by assisted reproductive technologies and childhood asthma at 7 years in the registry-based cohort
| Conceived by assisted reproductive technologies | N controls | N cases | Unadjusted OR (95% CI) | Adjusted* OR (95% CI) |
| No | 10 171 | 8793 | 1 | 1 |
| Yes | 123 | 130 | 1.26 (0.89 to 1.79) | 1.20 (0.85 to 1.71) |
*Adjusted for maternal age, parity and maternal current asthma.