Laboratory procedure in which an egg is fertilized by sperm in a specimen dish outside the woman's body.

In vitro fertilization (IVF) is a medical procedure that combines a human egg (ovum) and sperm in a laboratory dish to increase the possibility of conception. Two days after successful fertilization, the fertilized egg or embryo is placed in the woman's uterus, where it remains for a normal pregnancy and birth. Louise Brown became the first "test-tube baby" conceived using this procedure when she was born in England on July 25, 1978. Since then about 100,000 successful births have resulted from in vitro fertilization, but the procedure still has a relatively low success rate. When measured by the number of pregnancies achieved by the number of egg retrieval attempts, the overall IVF success in the United States is about 18%. (In other words, 18 pregnancies can be expected from 100 attempted egg...