This theory has been corroborated in two recent pilot studies. The first study, recently awarded the Prize Paper Award at the 2016 American Society for Reproductive Medicine Scientific Meeting, randomized embryos donated to research to 2% or 5% oxygen concentration after day 3 of development and found that embryos were twice as likely to blastulate if they were cultured in 2% oxygen concentration. However, embryos studied in this investigation were either abnormally fertilized or warmed from cryopreservation on day 3 after being donated to research. None were intended for clinical use.