Table 3.
Risk factors of pregnancy-related attack using univariate and multivariate Poisson regression
| Variable (number of pregnancies) |
Univariate analysis | Multivariate analysis | ||
| OR (95% CI) | P value | OR (95% CI) | P value | |
| Age at disease onset (76) | 0.97 (0.94–1.00) | 0.045* | — | 0.787 |
| Age at delivery/abortion | ||||
| 33–40 (12) | 1.00 | 1.00 | ||
| 26.5–33 (39) | 12.62 (1.89–84.10) | 0.009** | 10.17 (1.55–66.62) | 0.016* |
| 20–26.5 (25) | 12.96 (1.93–87.01) | 0.008** | 8.45 (1.26–56.71) | 0.028* |
| Time interval from disease onset to pregnancy (76) | 1.01 (0.96–1.07) | 0.573 | — | — |
| Time interval from last attack to pregnancy (76) | 1.00 (1.00–1.01) | 0.253 | — | — |
| Treatment during pregnancy and after delivery/abortion | ||||
| Adequate treatment† (10) | 1.00 | 1.00 | ||
| Inadequate treatment‡ (66) | 5.07 (1.44–17.89) | 0.011* | 4.32 (1.34–13.94) | 0.014* |
| AQP4-ab titre | ||||
| <1:100 or negative (45) | 1.00 | 1.00 | ||
| ≥1:100 (31) | 1.89 (1.22–2.91) | 0.004** | 1.56 (1.03–2.37) | 0.036* |
| Relapse within 1 year before pregnancy | ||||
| No (58) | 1.00 | |||
| Yes (18) | 0.75 (0.39–1.42) | 0.376 | — | — |
| ARR before pregnancy (76) | 0.70 (0.41–1.20) | 0.198 | — | — |
| EDSS score before pregnancy (76) | 0.99 (0.82–1.20) | 0.952 | — | — |
| Counts of concomitant auto-antibodies§ | ||||
| <1 (42) | 1.00 | |||
| ≥1 (34) | 1.13 (0.72–1.79) | 0.593 | — | — |
| Counts of concomitant auto-antibodies§ | ||||
| <2 (51) | 1.00 | |||
| ≥2 (25) | 1.16 (0.71–1.90) | 0.558 | — | — |
*P<0.05; **p<0.01.
†Adequate treatment was defined as (1) usage of relatively higher dose oral prednisone (>10 mg/day), (2) usage of immunosuppressant (azathioprine 100 mg/day or tacrolimus 3 mg/day) combined with or without oral steroid, (3) a dose of rituximab (375 mg/m2) within 6 months before conception and shortly after delivery.
‡Inadequate treatment referred to (1) no treatment at all, (2) usage of low-dose oral prednisone (≤10 mg/day) as single therapy.
§Including antinuclear antibody, extractable nuclear antigen antibody, double-stranded DNA antibody, antineutrophil cytoplasmic antibody, anticardiolipin antibody, thyroid peroxidase antibody and thyroglobulin antibody.
AQP4-ab, aquaporin-4 antibody; ARR, annualised relapse rate; EDSS, Expanded Disability Status Scale.