Scientific experiments on human embryos were first initiated for research to develop in vitro fertilization (IVF)—literally “fertilization in glass”—to enable infertile couples to have children. In this procedure, eggs and sperm are taken from a couple and fertilized by scientific means, outside of sexual reproduction. The resulting early staged embryos, or blastocysts, are implanted into the mother’s womb with the intent to achieve pregnancy.

Although efforts at in vitro fertilization with animals can be traced back to the late 1800s, it was not until 1965 that IVF technologies were applied to human reproduction. In 1971, researchers Patrick Steptoe, Robert Edwards, and Jean Purdy publicly announced that they had produced the first in vitro human blastocyst. Seven years later, Steptoe and Edwards announced the birth of Louise Brown, the first child to be been born as a result of in vitro fertilization. By...