The opinion’s plain language permits later term regulation, so I don’t know to whom you refer when you say it was interpreted as de facto prohibition on abortion. But you’re 100% correct that Casey had a major impact, as did other cases:
Webster v. Reproductive Health Services
In this case, the Court upheld several abortion restrictions, and modified the Roe trimester framework
Gonzales v. Carhart
On April 18, 2007, the Supreme Court handed down a 5 to 4 decision upholding the constitutionality of the Partial-Birth Abortion Ban Act.
The U.S. Supreme Court has ruled that the term “partial-birth abortion” in the act pertains to a procedure that is sometimes called “intact dilation and extraction” by the medical community.[2] Under this law, “Any physician who, in or affecting interstate or foreign commerce, knowingly performs a partial-birth abortion and thereby kills a human fetus shall be fined under this title or imprisoned not more than 2 years, or both.” The law was enacted in 2003, and in 2007 its constitutionality was upheld by the U.S. Supreme Court, in the case of Gonzales v. Carhart.
The bottom line is, this statement, “Roe v. Wade stands for the proposition that abortion CAN’T be regulated” is entirely false. It can, as expressed in Roe (see my excerpted passages), and has been, see cases above.
The Roe opinion itself was limited to the first trimester. But later, they ruled in other cases that the right to abortion applied in the second and third trimester as well, all the way up until the moment of birth. So the baby could be partially born, yet the mother still had a right to abortion.
It’s not “entirely false.” That is the spirit of Roe v. Wade. There are minor, entirely negligible exceptions like parental notification and partial birth abortion, which could even be described as non-exceptions. Parental notification applies only to minors. Obviously, a minor has no right to make every decision for herself. But that doesn’t mean she doesn’t have a right to abortion. It just means she’s got to give notification to the person who is legally entitled to make these decisions. As far as partial birth abortion is concerned, I’m not sure I would even call it abortion. More like infanticide.