Is it ok for a pregnant woman to maturate?

Yes: Yes there is no reason a pregnant women should not be allowed to, or should be concerned with masturbation. It is considered safe.

Masturbation : Masturbation is a normal and common part of the human experience. All men and many women masturbate. There are no health or medical reasons not to masturbate. So, yes, it is safe and normal to masturbate when you are pregnant.