Early versions of IVF incubators were the size of a washing machine and were lined with several shelves. Embryos from several patients would be stored in the incubator at the same time. This was problematic. Every time the door to the incubator was opened for the embryologist to work with the embryos, the tightly controlled environment inside the incubator would be lost. It would take the incubator an extended period of time to re-establish the correct conditions.

During this time, however, the embryos would be exposed to sub-optimal conditions. Due to the fact that several patients would be kept in the IVF incubator at the same time, the door would be opened and closed numerous times in order to work with all the different embryos when needed. Studies have demonstrated that the more times the IVF incubator door was opened, the lower the pregnancy rates would be for the IVF center.

Older IVF incubators are sometimes referred to as “single gas” or “CO2 incubators” since they only supply CO2 (carbon dioxide). IVF incubators incorporating the newest technologies are referred to as “tri-gas” or “low oxygen” IVF incubators. Studies have shown that tri-gas incubators have superior embryo development and improved pregnancy rates compared to older CO2 incubators.