system
Given the following post, respond as if you're commenting on Reddit:
human
In the context of the Ohio abortion bill, how is the reimplant of the embryo different than a surrogacy?

Sorry if I got any terminology wrong, it's not one of my strengths. Everyone keeps saying it's impossible to perform what the bill requires but it seems similar to how I imagine a surrogacy implantation in my head.
gpt
Surrogacy takes a pre-implanted embryo and puts it into a non-pregnant woman’s uterus, where it implants; alternatively, sometimes surrogacy involves the woman’s own egg and artificial insemination. In either case, the embryo implants in the uterus.

The process of implantation is complex and detailed on a microscopic level; the embryo’s placenta builds up blood vessels that grow into the lining of the uterus and line up with the woman’s vessels on a cellular level and makes millions of connections. This *very intimate* connection has to be made to allow the embryo’s/fetus’ blood to be oxygenated, filtered, and supplied with nutrients by the woman’s body. Basically, the placenta is a liver, kidney, and lung combined for the developing embryo. On the woman’s side, the lining of the uterus is a specialized tissue that allows this intense, deep ingrowth of embryonic/fetal tissue *temporarily.* the whole structure is shed, (usually) safely,  after a baby is born. 

An ectopic pregnancy is when the embryo attempts to grow into the tissue of a woman’s (usually) Fallopian tube, the lining of which did not evolve to safely allow this kind of invasive ingrowth, nor to stretch to the degree that a uterus allows as the fetus grows. The developing placenta can’t be removed without tearing up the Fallopian tube, because it doesn’t have that detachable lining, and the placenta can’t re-grow those fine, microscopic, millions-fold connections after it has already tried to implant somewhere else. Just sticking an embryo in the right spot would be like sticking a raw chunk of liver in someone and calling it an organ transplant, without joining up any of the blood vessels or ducts, etc. Except worse, since the placental connections are microscopic and there are about seven orders of magnitude more of them.

Basically, it is entirely physically impossible to do with current technology, and will be until we have nanobots.

Edited for a terminology error.