Some are raising concerns about the future of in vitro fertilization (IVF), as well as certain types of birth control, in the wake of the Supreme Court’s ruling that overturned Roe v. Wade. Vice President Kamala Harris expressed those concerns ahead of the ruling.

“States with abortion bans could potentially restrict IVF (In vitro fertilization) if their definition of life begins at the point of fertilization,” Vice President Harris said earlier this month. “If Roe was overturned, we believe that states with abortion bans from the moment of fertilization could potentially restrict specific types of contraception, in particular IUDs (Intrauterine device) and the so-called morning after pill.”

As Harris alluded to, some states have bills or laws that say life begins at fertilization. Under those terms, procedures that intervene with fertilized eggs could be banned.

IVF involves eggs being extracted and fertilized. The healthy embryos are implanted, while the unused ones are frozen or discarded.

Under some states’ definition of when life begins, this could be considered tampering with fertilized eggs and therefore illegal. A patient would need to store or donate these embryos.

Unlike IVF, certain birth control methods such as IUDs and Plan B do not intervene with fertilized embryos, but prevent fertilization in the first place. Because of that difference, IVF is more likely than birth control to be affected by the overturning of Roe v. Wade.

While birth control may be safe for now, that may not be the case forever. In his opinion on Dobbs v. Jackson Women’s Health Organization released Friday, Justice Clarence Thomas suggested the Court take a closer look at the Supreme Court case that guaranteed the right to contraceptives.

“The resolution of this case is thus straightforward. Because the Due Process Clause does not secure any substantive rights, it does not secure a right to abortion,” Justice Thomas said. “For that reason, in future cases, we should reconsider all of this Court’s substantive due process precedents, including Griswold, Lawrence, and Obergefell.”

Griswold v. Connecticut established the right to obtain contraceptives, Lawrence v. Texas established the right to privacy related to sex, and Obergefell v. Hodges allowed gay marriage to be legal.