In the three decades since the landmark birth of the first “test tube baby,” the options for assisted reproduction have expanded and the ethical questions have grown more complex.
In vitro fertilization (the original “test tube” technique) involves mixing eggs and sperm in a petri dish and implanting the fertilized eggs. To help men with low sperm count become biological fathers, there is an in vitro procedure called intracytoplasmic sperm insertion in which a single sperm is injected into an egg. If a woman’s eggs are unsuitable, a novel technique called ooplasm transfer may be beneficial. It combines the nuclear genetic material of her eggs with the cytoplasm of a younger woman’s eggs and the sperm of the first woman’s partner. Thus it is now possible for a baby to be genetically related to more than two parents.