Abortion is generally legal, as decided by Roe vs. Wade (1973). But more narrowly speaking, States were also granted the privilege to limit and curtail abortion practice to prevent abuse, or, for example, treating abortion like a form of contraception. Several brands of abortion-restriction have successfully passed at the state level. These are:

1) Late-term Abortion Bans (banning 24 weeks/3rd trimester)
2) Fetal Pain Bill (banning 20th week-later abortions)
3) Parental Consent
4) Informed Parents
5) Waiting Period