I'm reading the Wikipedia article on Roe v Wade. It says that:
Texas's lawyers had argued that total bans on abortion were justifiable because "life" began at the moment of conception, and therefore its governmental interest in protecting prenatal life applied to all pregnancies regardless of their stage. The Court said that there was no indication that the Constitution's uses of the word "person" were meant to include fetuses, and it rejected Texas's argument that a fetus should be considered a "person" with a legal and constitutional right to life.
 - Chemerinsky, Erwin (2019). Constitutional Law: Principles and Policies (6th ed.). New York: Wolters Kluwer. ISBN 978-1-4548-9574-9.
 - Nowak, John E.; Rotunda, Ronald D. (2012). Treatise on Constitutional Law: Substance and Procedure (5th ed.). Eagan, Minnesota: West Thomson/Reuters. OCLC 798148265.
but the page says, quoting the same sources, that:
But [the supreme court] also ruled that this right [to having an abortion] is not absolute, and must be balanced against the government's interests in protecting women's health and protecting prenatal life.
Setting aside the question of the pregnant woman's health, what is the basis the court found for the state having a valid interest in fostering pre-natal life when the subject/citizen carrying the fetus can legitimately decide not to develop it into a living person by giving birth?
Possibly related question: How low is the bar for "legitimate government interest"?