A posterior placenta means that your placenta has implanted onto the back of your uterus. This means that you have the advantage of feeling your baby's movements earlier and stronger as well as allowing the baby to get into the most optimum position for birth (spine at the top of your belly - anterior).

Is it okay for the placenta to be in the back?

If your health care provider determines that you have a posterior placenta, there's no need to worry. It's completely normal. The upper (or fundal) portion of the uterine back wall is one of the best locations for the fetus to be in.

Is it true that posterior placenta means baby boy?

Posterior placenta linked to gender of fetus: There is no scientific evidence that proves that a posterior placenta means a boy or a girl. The same holds true for a fundal posterior placenta and an anterior placenta.