Oxygen tension in embryo culture: does a shift to 2% O2in extended culture represent the most physiologic system?
There has been much debate regarding the optimal oxygen tension in clinical embryo culture. The majority of the literature to date has compared 5% oxygen to atmospheric levels (20-21%). While the majority of modern IVF labs have accepted the superiority of 5% oxygen tension, a new debate has emerged regarding whether a further reduction after day 3 of development represents the most physiologic system. This new avenue of research is based on the premise that oxygen tension is in fact lower in the uterus than in the oviduct and that the embryo crosses the uterotubal junction sometime on day 3. While data are currently limited, recent experience with ultra-low oxygen (2%) after day 3 of development suggests that the optimal oxygen tension in embryo culture may depend on the stage of development. This review article will consider the current state of the literature and discuss ongoing efforts at studying ultra-low oxygen tension in extended culture.
Reproductive Medicine Associates of New Jersey, Basking Ridge, NJ, 07920, USA. smorin@rmanj.com.|Sidney Kimmel Medical College, Thomas Jefferson University, Philadelphia, PA, 19107, USA. smorin@rmanj.com.
Scott J
SJ
Morin
D001755:Blastocyst / Q000378:metabolism / Q000502:physiology; D046149:Embryo Culture Techniques / Q000379:methods*; D004624:Embryo Transfer / Q000379:methods; D005260:Female; D005307:Fertilization in Vitro; D006801:Humans; D010100:Oxygen / Q000378:metabolism*; D011247:Pregnancy; D018873:Pregnancy Rate; D027724:Reproductive Techniques, Assisted
D010100:Oxygen
Blastocyst transfer; Embryo culture; Extended culture; In vitro fertilization; Oxygen tension