A Study Evaluating B Cell Levels In Infants Potentially Exposed To Ocrelizumab During Pregnancy

Inclusion Criteria: * Diagnosis of MS or CIS (in line with the locally approved indications) * Currently pregnant with singleton pregnancy at gestational week ≤30 at enrolment * Documentation that first and second obstetric ultrasound has been conducted before enrolment during the screening period * Documentation that the last exposure to ocrelizumab occurred up to 6 months before the LMP before the woman became pregnant OR during the first trimester of pregnancy Exclusion Criteria: * Last exposure to ocrelizumab \>6 months before the woman's LMP or later than the first trimester of pregnancy * Gestational age at enrolment \>30 weeks * Non-singleton pregnancy * Received the last dose of ocrelizumab at a different posology other than per the local prescribing information * Lack of access to ultrasound pre-natal care as part of standard clinical practice * Prior or current obstetric/gynecological conditions associated with adverse pregnancy outcomes * Pre-pregnancy body mass index \>35 kg/m2 * Any concomitant disease that may require chronic treatment with systemic corticosteroids or immunosuppressants during the course of the study * Prior or current history of primary or secondary immunodeficiency, or woman in an otherwise severely immunocompromised state * Significant and uncontrolled disease that may preclude a woman from participating in the study * Women with known active malignancies or being actively monitored for recurrence of malignancy including solid tumors and h…