Outcomes, n (%, 95% CI) | Interferon β-1b-exposed pregnancies | Relative risk (95% CI) |
---|---|---|
Live births (N=96) | 83 (86.4) | – |
Birth defects (N=86)* | 5 (5.8, 1.9 to 13.0) | 2.1 (0.9 to 4.9), p=0.092† |
Spontaneous abortions (N=96) | 11 (11.5, 5.9 to 19.6) | 0.7 (0.4 to 1.2), p=0.8603‡ |
Stillbirth (N=96) | 2 (2.1) | – |
Maternal deaths | 0 (0) | – |
Infant deaths | 0 (0) | – |
Ectopic pregnancies | 0 (0) | – |
*Excludes spontaneous and elective abortions <20 weeks gestation with reported birth defects per Metropolitan Atlanta Congenital Defects Program (MACDP) convention. The denominator is restricted to live births.
†Relative risk compared with 2.78% reported by MACDP; Fisher's exact test based on binomial distribution for exposures.20 ,21
‡Relative risk compared with 16% rate of spontaneous abortion reported by National Survey of Family Growth (NSFG); Fisher's exact test.23