Embryo culture conditions: why the IVF lab matters
By the MyBabyBridge editorial team · · Last reviewed · 2 min read
Embryo culture, the process of growing embryos in the lab for several days, aims to give embryos conditions as close as possible to those in the body. Many factors in the IVF lab can affect it, including culture media, equipment, gases, air quality, and procedures.
Features of a well-run culture system
- Low oxygen: A Cochrane review concluded that culturing embryos at low oxygen concentrations improves IVF and ICSI success rates compared with atmospheric oxygen.
- Clean air: Labs use air filtration to limit volatile organic compounds (VOCs) and other pollutants.
- Stable conditions: Temperature, pH, and gas levels are monitored continuously, and quality-controlled culture media are used.
- Extended culture when appropriate: Many clinics grow embryos to the blastocyst stage (day 5 or 6), which allows more assessment before transfer. Whether this is best depends on how many embryos a patient has.
- Vitrification: Fast freezing is widely used to store eggs and embryos.
- Single embryo transfer: Transferring one embryo at a time lowers the risk of twins and higher-order multiples.
Measuring success
Good labs track outcomes per embryo transferred, such as implantation rate, miscarriage rate, and live births, not just pregnancy tests. MedlinePlus notes that pregnancy rates and live birth rates differ, because not all pregnancies result in a live birth.
Be cautious with extras
Some lab techniques are sold as add-ons. The UK regulator HFEA notes that most patients do not need them and rates the evidence for many as limited.