Unused embryos stored at IVF clinics in the United States can be handled in various ways based on the preferences of the patients who undergo fertility treatments. When patients have remaining embryos after completing their fertility treatments, they face decisions regarding the disposition of these unused embryos.

The options available for the disposition of unused embryos include:

1. Donation: Patients can choose to donate their unused embryos to other couples who are struggling with infertility and wish to have a child. There are specific programs and organizations that facilitate embryo donation, allowing the embryos to be transferred to recipients for implantation.

2. Preservation: Patients may decide to keep their unused embryos frozen at the IVF clinic for future use. This option provides the possibility of using the embryos in subsequent IVF cycles if the patients decide to undergo additional fertility treatments to have more children.

3. Destruction: If patients no longer wish to use their unused embryos and do not want to donate them, they may opt for the destruction of the embryos. IVF clinics follow specific protocols and guidelines for the safe and ethical disposal of unused embryos.

Ultimately, the decision regarding the disposition of unused embryos is a personal and complex one for patients undergoing fertility treatments. It is essential for individuals to carefully consider their options, seek counseling or support if needed, and ensure that they are fully informed about the implications of each choice.

Please note that regulations and practices regarding the disposal of unused embryos may vary by state in the United States, and it is recommended for patients to consult with their healthcare providers