Competing interests: GM: none. SH has received unrestricted educational grants or speaking honoraria from Biogen, Merck Serono, Novartis, Roche and Sanofi Genzyme. DR has received honoraria for speaking, advisory boards and/or traveling from Biogen, Celgene, Hikma, Janssen, MedDay, Merck, Neuraxpharm, Novartis, Roche, Sanofi Genzyme and Teva. His institution has received research income from Actelion, Biogen, GW Pharmaceuticals, Janssen, Merck Serono, Mitsubishi, Novartis, Sanofi Genzyme, Teva and TG Therapeutics. PB, in the past 5 years, has received sponsorship to attend education meetings or honoraria for attending advisory boards or speaking at meetings from Merck, Roche, Biogen, Janssen and Sanofi-Genzyme. RD has received honoraria for speaking and/or traveling from Biogen, Merck, Teva, Janssen, Esai and Sanofi. She served on advisory board of Roche, Biogen, Janssen, Sandoz and Merck. She has received grant support from Biogen, Merck, Celgene, Barts Charity, the UK MS Society, NMSS, MRC, and the Home Family Charitable Trust and is CI of the UK MS Pregnancy Register.