Number of events, crude event rates (per 1000), crude IRRs and adjusted HRs for the four outcomes and each of the AEDs studied—study population limited to women considered to be treated for epilepsy
| Events | Crude event rates | IRR | HR* (95% CI) | HR† (95% CI) | |
| Neurodevelopmental disorders | |||||
| Lamotrigine | 32 | 4.2 | |||
| Carbamazepine‡ | 1 | 1.5 | 0.4 (0.0 to 2.7) | 0.2 (0.0 to 2.7) | 0.2 (0.0 to 2.7) |
| Levetiracetam | 8 | 3.7 | 0.9 (0.4 to 1.9) | 0.8 (0.4 to 1.8) | 0.8 (0.4 to 1.8) |
| Valproic acid | 50 | 13.5 | 3.2 (2.0 to 5.0) | 3.2 (2.0 to 4.9) | 3.5 (2.3 to 5.4) |
| Pervasive developmental disorders | |||||
| Lamotrigine | 7 | 0.9 | |||
| Carbamazepine‡ | 0 | 0.0 | N/A | N/A | N/A |
| Levetiracetam | 4 | 1.8 | 2.0 (0.6 to 6.8) | 1.8 (0.5 to 6.6) | 1.8 (0.5 to 6.6) |
| Valproic acid | 17 | 4.5 | 4.9 (2.0 to 11.8) | 4.9 (2.0 to 11.8) | 4.7 (1.9 to 11.4) |
| Mental retardation | |||||
| Lamotrigine | 10 | 1.3 | |||
| Carbamazepine‡ | 0 | 0.0 | N/A | N/A | N/A |
| Levetiracetam | 1 | 0.5 | 0.3 (0.0 to 2.7) | 0.4 (0.1 to 2.9) | 0.4 (0.1 to 2.9) |
| Valproic acid | 15 | 4.0 | 3.0 (1.4 to 6.7) | 3.1 (1.4 to 7.0) | 4.0 (1.9 to 8.6) |
| Visits to a speech therapist | |||||
| Lamotrigine | 122 | 16.2 | |||
| Carbamazepine‡ | 4 | 6.1 | 0.4 (0.1 to 1.0) | 0.2 (0.1 to 0.7) | 0.2 (0.1 to 0.7) |
| Levetiracetam | 22 | 10.2 | 0.6 (0.4 to 1.0) | 0.7 (0.4 to 1.1) | 0.7 (0.4 to 1.1) |
| Valproic acid | 93 | 25.1 | 1.6 (1.2 to 2.0) | 1.4 (1.1 to 1.8) | 1.5 (1.1 to 1.9) |
Lines marked in bold correspond to HRs for which the 95% CI does not include 1.
*Adjusted for all covariates except hospitalisation for epilepsy during pregnancy.
†Adjusted for all covariates including hospitalisation for epilepsy during pregnancy.
‡No possible adjustment for the proxy for alcohol.
AED, antiepileptic drug; CI, confidence interval; HR, hazard ratio; IRR, incidence rate ratio; N/A, not applicable.