Vaginismus is the involuntary contraction of vaginal muscles that causes pain during sex. This contraction will not influence the other functions of the rest of the reproductive system.
Likewise, vaginismus is not a cause of sterility (a situation in which a couple has tried to get pregnant for at least one week without success), much less infertility (repeated miscarriage), except in the situation where vaginismus prevents complete sexual intercourse, of course.