HIV virus cannot transmitt through placenta why?
Answers:
in the placenta, no blood is shared between mother and infant. the placenta diffuses the good nutrients from the mothers blood and after diffuses it into the babys blood. the HIV virus is in the blood singular so the only passageway it can be passed from mother to baby is during childbirth. because no blood is shared babies can be born next to a completely different blood type to their mothers.
Not sure what you are asking? HIV is transferred by mother to baby, by agency of placenta by way of maternal/fetal blood flow. So yes I would voice it crosses the placenta.
It doesn't usually cross the placenta because there is a membrane separating the mother's blood from the fetus's. The membrane let nutrients and gases approaching oxygen pass, but not usually larger particle like cell or viruses.
Sometimes, especially slowly in the pregnancy, the membrane can gain broken, allowing small amounts of the mother's blood to come in direct contact next to the fetus's. Some mother to baby infections can ensue then, but most mother to babe-in-arms transmission occur during birth or through breastfeeding.