No. In the majority of cases, MS does not affect life expectancy. 

There are unusual variants of MS that can be very aggressive and potentially shorten life, but these are not the norm. MS tends to affect quality of life, not quantity of life; people with multiple sclerosis often live just as long as those without it, but the symptoms and disease progression can affect how well they live day-to-day. With appropriate treatment and management, these effects on quality of life can be minimized.