Incidence of pregnancy and disease-modifying therapy exposure trends in women with multiple sclerosis: A contemporary cohort study

Mult Scler Relat Disord. 2019 Feb;28:235-243. doi: 10.1016/j.msard.2019.01.003. Epub 2019 Jan 3.

Abstract

Background: Exposure to disease-modifying therapy (DMT) during early pregnancy in women with relapsing-remitting MS (RRMS) may be increasing.

Objective: To retrospectively determine incidence of pregnancy, DMT exposure and pregnancy outcomes in women with RRMS.

Methods: We identified all women with RRMS aged 15-45 years in the MSBase Registry between 2005-2016. Annualised pregnancy incidence rates were calculated using Poisson regression models. DMT exposures and pregnancy outcomes were assessed.

Results: Of 9,098 women meeting inclusion criteria, 1,178 (13%) women recorded 1,521 pregnancies. The annualised incidence rate of pregnancy was 0.042 (95% CI 0.040, 0.045). A total of 635 (42%) reported pregnancies were conceived on DMT, increasing from 27% in 2006 to 62% in 2016. The median duration of DMT exposure during pregnancy was 30 days (IQR: 9, 50). There were a higher number of induced abortions on FDA pregnancy class C/D drugs compared with pregnancy class B and no DMT (p = 0.010); but no differences in spontaneous abortions, term or preterm births.

Conclusions: We report low pregnancy incidence rates, with increasing number of pregnancies conceived on DMT over the past 12-years. The median duration of DMT exposure in pregnancy was relatively short at one month.

Keywords: Incidence; Multiple sclerosis; Outcomes; Pregnancy; Therapy.

MeSH terms

  • Adolescent
  • Adult
  • Cohort Studies
  • Female
  • Follow-Up Studies
  • Humans
  • Immunologic Factors / therapeutic use
  • Incidence
  • Multiple Sclerosis, Relapsing-Remitting / epidemiology*
  • Multiple Sclerosis, Relapsing-Remitting / therapy*
  • Pregnancy
  • Pregnancy Complications / epidemiology*
  • Pregnancy Complications / therapy*
  • Pregnancy Outcome
  • Registries
  • Retrospective Studies
  • Young Adult

Substances

  • Immunologic Factors