How many unused embryos are stored in fertility clinics in the United States?
Embryos that are not immediately used for fertility treatments are often frozen by fertility clinics for potential future use. According to a survey conducted by Rand Health in 2003, there are approximately 400,000 such embryos in storage in the United States . (Source: Hoffman, D.I., et al. 2003. Cryopreserved embryos in the United States and their availability for research. Fertility and Sterility 79: 1063-1069.) Most of these embryos will never be used for fertility treatment (either because the parents are successful in having the children they want or because treatment is unsuccessful). According to the study, about two percent of these excess embryos are offered by the parents for adoption to create pregnancies in biologically unrelated mothers. Many parents are uncomfortable and unwilling to offer their excess embryos for adoption and would prefer to simply discard these embryos or to donate them for medical research that could help people.
