The law of independent assortment says that the traits are randomly selected, there is no pattern to how they are sorted. The law of segregation says that the traits are divided between each gamete, using a pattern to sort them.
Your answer should be: Providing nutrients to the fetus, cushioning and protecting the fetus. Mixing the blood of the Mother and Fetus would not protect him/her from drugs because if it is in the Mother's system then it will affect the Fetus.