Table 2.
Effectde composition of the influence of rheumatoid arthritis and potential mediators on adverse pregnancy outcomes in 3 million live births in the state of California
| Mediator | Total effecta | Direct effectb | Indirect effectc | Proportion mediatedd | |||
|---|---|---|---|---|---|---|---|
| aRR | 95%CI | aRR | 95%CI | aRR | 95%CI | ||
| Preterm Birth | |||||||
| Preeclampsia/hypertension | 1.97 | (1.78, 2.17) | 1.77 | (1.60, 1.96) | 1.11 | (1.08, 1.13) | 20.4% |
| Gestational diabetes | 1.98 | (1.80, 2.19) | 1.96 | (1.78, 2.17) | 1.01 | (1.00, 1.02) | 2.2% |
| Infection in pregnancy | 1.99 | (1.81, 2.20) | 1.92 | (1.74, 2.12) | 1.04 | (1.03, 1.05) | 7.4% |
| Cesarean Delivery | |||||||
| Preeclampsia/hypertension | 1.22 | (1.15, 1.29) | 1.19 | (1.12, 1.26) | 1.02 | (1.02, 1.03) | 13.3% |
| Gestational diabetes | 1.23 | (1.16, 1.30) | 1.22 | (1.15, 1.29) | 1.01 | (1.00, 1.01) | 3.0% |
| Infection in pregnancy | 1.23 | (1.16, 1.30) | 1.22 | (1.15, 1.29) | 1.01 | (1.01, 1.01) | 3.6% |
| Small for Gestational Age | |||||||
| Preeclampsia/hypertension* | 1.53 | (1.37, 1.73) | 1.49 | (1.33, 1.66) | 1.03 | (1.01, 1.05) | 8.3% |
| Gestational diabetes | 1.53 | (1.37, 1.73) | 1.53 | (1.38, 1.71) | 0.99 | (0.99, 0.99) | 3.0% |
| Infection in pregnancy | 1.53 | (1.37, 1.73) | 1.52 | (1.36, 1.69) | 1.01 | (1.00, 1.01) | 1.5% |
Models adjusted for race/ethnicity, maternal age, insurance provider, maternal education, overweight/obesity, and smoking
a
Effect of rheumatoid arthritis on adverse pregnancy outcomes
b
Effect of rheumatoid arthritis on adverse pregnancy outcomes that is not mediated by each pregnancy complication
c
Effect of rheumatoid arthritis on adverse pregnancy outcomes mediated by each pregnancy complication
d
Proportion of effect of rheumatoid arthritis on adverse pregnancy outcomes mediated by each pregnancy complication
*
modeled with interaction term between exposure and mediator