This month, two fertility facilities acknowledged that their storage systems have failed. Pacific Fertility Clinic in San Francisco said that there had been a liquid nitrogen failure in one of its tanks holding thousands of eggs and embryos. In Cleveland, University Hospitals Ahuja Medical Center announced that a storage tank holding 2,000 eggs and embryos had suddenly heated up, damaging its contents.
The news is heartbreaking. People count on these fertility banks to store what could become their future children. It made us wonder: Are people in Austin at risk for losing their eggs and embryos? We talked to Tex VerMilyea, laboratory and operations director for Ovation Fertility, the lab attached to Texas Fertility Center.
The news, he said, caused Ovation Fertility to re-evaluate its systems, and once more is known about what happened in the cases in San Francisco and Cleveland, more re-evaluation will be done.
“This is the worse nightmare of anyone in the field,” VerMilyea said. “It’s a wake up call to make sure we are being diligent.”
Right now, at the facility, each cryotank where eggs, embryos and sperm are stored records a temperature every five minutes. If there’s any fluctuation above five degrees, it triggers an alarm tree that notifies VerMilyea, the facility manager and the supervisor. Every day VerMilyea receives a report of what the temperatures have been in each tank for the last 24 hours. Ovation Fertility also inspects the tanks daily to look for condensation, which would point out that the vacuum seal around the tank is failing. The tanks are topped off with more liquid nitrogen once a week.
The tanks Ovation Fertility use submerge the tissue in liquid nitrogen, rather than using just some liquid nitrogen and allowing the vapor from the nitrogen to do the cooling. The tanks are set to be -196 Celsius, with an alarm sounding at -191 Celsius. If the tank used vapor, the temperature inside would be between -180 and -140 Celsius. -139 is when cells start to degrade. Some facilities use the vapor method because there is a theoretical risk of contamination using liquid only and vapor is cheaper. VerMilyea said because Ovation Fertility uses the liquid method, if something did happen, they would have time to move the embryos, egg and sperm to another tank before the tank hit -139 Celsius. We don’t yet know whether the tanks in San Francisco and Cleveland used 100 percent liquid nitrogen or some liquid and some vapor.
Labs also have to plan for what happens if there is a loss of power, floods, tornadoes, earthquakes, fires and more.
Theoretically, tissue stored at the correct temperature could last indefinitely. Recently, a 25-year-old woman gave birth using an embryo that was a year younger than herself.