Frozen embryos are preserved in tanks filled with liquid nitrogen. Credit: Tina Stallard/Getty Images
With in vitro fertilization (IVF) techniques, thousands of couples unable to conceive on their own have successfully given birth.
But what should couples do with leftover embryos? Should they be discarded, frozen for safe keeping or donated to medical research?
Mount Sinai Hospital in Toronto plans to make another option easier: the donation of frozen embryos to other couples through an anonymous donor program at its Center for Fertility and Reproductive Health.
Although the idea of embryo donation isn't new, its wider use is, suggests a detailed article from The Vancouver Sun.
So far, more than 500,000 embryos are stored frozen in U.S. fertility clinics, according to the Embryo Adoption Awareness Center.
During the IVF process, doctors create several embryos and select one to implant into a woman. Based on the decision of the couple, leftover embryos can be cryogenically preserved — or frozen at low temperatures — in liquid nitrogen.
The process differs from sperm or egg donations in that fertilization has already taken place and the embryos are ready to be implanted. Doctors can freeze these cells and thaw them years later without harm to the embryo.
But as IVF becomes more efficient and larger numbers of embryos are created for each couple, ethical considerations arise.
For individuals who choose to freeze their extra embryos, how long should they be able to store these embryos before thawing or discarding them? Is it ethical for a stored embryo to outlive its parents?
As questioned in The Vancouver Sun article, could a woman choose to freeze extra embryos for safe keeping and later give them to her infertile daughter, allowing the daughter to give birth potentially to her own siblings?
The answers aren't clear, and few laws create parameters around embryo donations. In the United States, embryos can be exchanged as property through contract law privately or through donation programs and clinics.
What do you think about these hypothetical situations? Should clinics restrict how long life can be frozen?