Natalizumab in Preventing Post-partum Relapses in Multiple Sclerosis

Inclusion Criteria:

1. Female subjects postpartum, 0-30 days postpartum at the time of informed consent.
2. Diagnosis of relapsing form of MS.
3. Willing to initiating natalizumab and enroll in the TOUCH system.
4. Willing and able to comply with the study procedures for the duration of the trial.
5. Signed informed consent and HIPAA authorization.

Exclusion Criteria:

1. Diagnosis of primary progressive MS.
2. Breastfeeding
3. Use of IVIG in Tysabri treated subjects.
4. Significant renal or hepatic impairment (in the opinion of the investigator) or other significant disease (e.g., cognitive impairment) that would compromise adherence and completion of the trial.
5. History of hypersensitivity to previous exposure or presence of antibodies to natalizumab.
6. Any other factor that, in the opinion of the investigator, would make the subject unsuitable for participation in this study.
7. Patients that experience relapses and/or initiated DMT's during pregnancy

The Control group will consist of relapsing MS patients post-delivery who decline natalizumab therapy but open to enroll in the study.

Similar Inclusion and Exclusion criteria as the natalizumab group with the exception of requiring TOUCH enrollment program. The Control group will be allowed to initiate any FDA approved DMT at any time post delivery or remain on no therapy while breastfeeding.