Pregnancy and Infant Outcomes in Multiple Sclerosis: Findings From the Global MAPLE-MS Pharmacovigilance Program

With its use being contradicted during pregnancy, limited information exists concerning pregnancy and infant outcomes on exposure to cladribine tablets before or during pregnancy in women with multiple sclerosis (MS). In this study, we assess cumulative pregnancy exposure to cladribine tablets and prevalence of pregnancy and infant outcomes in women with MS exposed during pregnancy or within 6 months before conception and pregnancies fathered by men with MS exposed within 6 months before conception.

MAPLE-MS, a 10-year enhanced pharmacovigilance program, uses a global patient safety database to assess pregnancy outcomes potentially associated with cladribine tablets exposure in MS. Data collection began after the first approval of cladribine tablets (August 22, 2017). The primary outcome is the prevalence of major congenital anomalies (MCAs) in offspring. Secondary outcomes include other pregnancy outcomes (live birth, elective termination, spontaneous abortion, ectopic pregnancy, and stillbirth).

In this Year 7 interim analysis, of 383 pregnancies analyzed, 336 (87.7%) involved maternal exposure to cladribine tablets and 47 (12.3%) were associated with paternal exposure. In the maternal exposure group, MCA prevalence (excluding genetic anomalies) in pregnancies with known outcomes was 1.1% (95% confidence interval [CI] 0.0-6.7; an atrial septal defect). Prevalence of live births in the maternal exposure group was 57.3% (95% CI 49.5-64.8). Secondary outcomes in the maternal exposure group were elective terminations (21.0% [95% CI 15.3-28.1]), spontaneous abortions (20.4% [95% CI 14.8-27.4]), and ectopic pregnancies (1.3% [95% CI 0.1-4.8]). In the paternal exposure group, no cases of MCA were observed in live births with known outcomes. Prevalence of live births was 81.3% (95% CI 56.2-94.2). Spontaneous abortions occurred in 12.5% (95% CI 2.2-37.3) and stillbirths in 6.3% (95% CI 0.0-30.3) of cases.

Results are limited by the small number of pregnancies with known outcomes. Of pregnancies with known outcomes, the majority resulted in live births, with low frequencies of elective terminations and stillbirths reported. Since 2017, a single MCA (atrial septal defect) has been reported to the global patients' safety database. The results align with published estimates from the general population and MS patient cohorts.