Surrogate Mother

embryosac,

I believe that the "genetic line" is determined solely by the DNA contained in the egg and sperm from the genetic parents, and would therefore be "set" before implantation in the surrogate.

However, any infectious diseases (such as HIV or hepatitis) that either the donors OR the surrogate has, could be transmitted to the other.

That is, the surrogate could contract diseases from an infectious embryo implantation, and a "healthy" embryo could contract diseases from an infected surrogate.

I agree to the point that the diseases contracted in the similar pattern but what if the chorionic and uterine linings are merged during the development. I mean to say that the placental lining will matter ???

It seems also that there must be blood exchange, if a disease like HIV can be transmitted in utero. There is a process where microbes of some types at least exchange genetic material- why would one assume that this trait is lost in higher life forms on a cellular level?

the placenta is a blood to blood nutrient, oxygen and waste exchanger that normally is a barrier to most things crossing. Some small entities, like virii 'may' cross, as can some antigenic materials, which can cause problems.

I wonder what would happen of you gestated 10 human embryos in a cow? would cross species implantation work? What about related species, as long as the system of the mother would tolerate the size of the transplanted foetus?