The fertilization of human oocytes in vitro was first achieved by Rober G. Edwards in 1968 but it was to be a further decade before the first test-tube baby, Louise Brown, was born. The human oocytes removed from the mother were fertilized in vitro and reintroduced into the womb. This glass incubator was one of several used by Steptoe and Edwards in the Oldham General Hospital at that time. They were essentially small glass desiccators sealed with ground glass stoppers at the top. The embryos were usually incubated in a gas mixture of 5% CO2 in air.