Is it possible for a mother that has hiv to pass on to her newborn?

Yes: Yes and a known carrier of HIV should have have their baby tested and properly treated as necessary to prevent HIV complications.

Yes: Yes it is possible, however if pregnant woman is treated with anti-hiv medications during pregnancy or at least during labor and baby after birth receives appropriate prophylaxis for several weeks, this risk is small but never 0. Expecting mother and newborn baby need to be followed by appropriate specialist and follow treatment recommendations.