Ocrelizumab is a medication used in this clinical trial. It is a type of drug known as a monoclonal antibody, which targets specific cells in the immune system. In this study, the focus is on infants who may have been exposed to ocrelizumab during pregnancy. The trial aims to understand if this exposure affects the levels of B-cells, a type of white blood cell, in these infants after birth.

Multiple Sclerosis – Multiple Sclerosis (MS) is a chronic disease that affects the central nervous system, particularly the brain and spinal cord. It is characterized by damage to the protective covering of nerve fibers, known as myelin, which disrupts communication between the brain and the rest of the body. Symptoms can vary widely and may include fatigue, difficulty walking, numbness or tingling, muscle weakness, and problems with coordination and balance. The disease often progresses with periods of relapses and remissions, where symptoms may improve or worsen over time. The exact cause of MS is unknown, but it is believed to involve an abnormal immune response.

Clinically Isolated Syndrome – Clinically Isolated Syndrome (CIS) is a neurological episode that lasts at least 24 hours and is caused by inflammation or demyelination in the central nervous system. It is often considered a precursor to Multiple Sclerosis, as it involves similar symptoms such as vision problems, muscle weakness, and sensory disturbances. CIS can be a single event or may lead to further neurological episodes, potentially progressing to MS. The progression from CIS to MS depends on various factors, including the presence of specific markers in the brain. Early intervention and monitoring are crucial to understanding the potential development of MS from CIS.