A reaction to in vitro fertilization

We just studied this form of assisted reproductive techniques in Biology 1. It's fine with me but what shocked me most was the mention of a surrogate mother. This is opted when the wife's reproductive system does not have the ability to conceive a child, no matter what kind of ART is used. Another mother, termed as the surrogate mother, is used to carry the baby. What bothered me was this: the embryo may have come from the married couple but it was the other woman who bore it. Isn't she considered as the mother of the child also? I was also wondering if that woman is paid by the couple. If so, does it satisfy her when she knows all along that the child she is carrying will be given to another even with the thought of money in her head? Isn't it unfair on the part of the surrogate mother? It's like taking another woman's child with her full knowledge.

Well, it just seemed weird to me.

One thing's for sure, the mother (where the oocyte came from) can't this to the child: "I carried you on my womb for nine months and this is what you're going to do?!?"

(I'm writing this for boredom's sake.)