Trophoblast is *weird* so no one is really sure. It is difficult to research because it's adapted for an environment that's difficult to recreate in a lab (inside a uterus, in the lining, which is mostly natural killer immune cells from another individual) and we can't really go looking during a pregnancy. I've seen some studies showing persistent remodeling effects up to seven years postpartum and others (like this one) that suggest that the majority of the remodeling is gone by 2 years postpartum.
I wonder if some trophoblast are carrying genes that mean they persist longer, or their remodeling effects persist longer. I would like to know!
