 IVF involves fertilizing ova outside the womb and transferring resulting embryos into the uterus. The woman whose ova are used is given a hormone treatment that induces producing multiple ova, which are harvested by a needle inserted through the vaginal wall. Fertilization may involve incubating the ovum in sperm or injecting a single sperm into the ovum in intracytoplasmic sperm injection (ICSI). Several embryos are transferred into the uterus after three to five days. Since the birth of the first “test-tube baby” in 1978, IVF has become a fairly common procedure for addressing certain forms of infertility.