What Keeps Egg-Freezing Operations From Failing?

What Keeps Egg-Freezing Operations From Failing?
From Wired - March 13, 2018

On March 4, an embryologist at Pacific Fertility Center was doing a routine walk-through of the clinics collection of waist-high steel tanks, each one filled with thousands of liquid nitrogen-bathed vials of frozen sperm, eggs, and embryos. The San Francisco-based clinic offers cryogenic cold storage and in vitro fertilization services for patients throughout the Bay Area, many of whom work for tech companies with hefty fertility benefits packagesApple, Google, Facebook, Pinterest, LinkedIn. PFC charges its patients $600 a year for storage alone, which covers the personnel required to maintain the tanks, according to its website. Every day someone has to do a physical inspection of the equipment, and staff are on-call 24/7. But that Sunday, the embryologist discovered that in one tank, Tank No. 4., the liquid nitrogen levels had slipped to dangerously low levels.

PFC staff immediately began transferring the threatened tissues to a spare storage tank filled with liquid nitrogen. They then spent the next five days sorting through records to figure out which patients had been affectedabout 500 in total. Calls and emails began going out over the weekend. Bill Taroli, though, found out on the nightly news.

This past Sunday night, he was watching at home in California's Castro Valley when a story came on about a tank malfunction at a fertility clinic in Cleveland. At first, he almost didnt notice when the letters PFC popped up on a corner of the screen. He had to roll it back and rewatch the segment three more times before he realized the reporter was indeed saying that another failure had also taken place at Pacific Fertility Center, on the same day. Tarolis stomach knotted up. That was the clinic where he and his husband had four frozen embryosthree boys and a girlwaiting to one day join their family.

The couple had worked with PFC to bring their son into the world five years ago, and had always planned on having another child. So on Monday, Taroli emailed the clinic and in the evening got a call from their physician, Dr. Eldon Schriock. He was kind, but frank. All of their embryos had been stored together in the same vial, in the tank that had failed. They were going to thaw one of them to see if it was still alive. If one was gone, theyd all be gone. It would take a week or two to know for sure.

Were kind of in a holding pattern right now, like a weird limbo state, says Taroli. PFC told him theyve already tested some tissues and found them to be viable. But it could be months before every patient has a concrete answer. Having been through this before theres a part of us that knows it was never a sure thing," he says. "But having the door completely closed on you is very different. The only thing buoying me up right now is the hope that we may still find there was no damage. At this point we just dont know.

Even though more than 5 million babies have been born thanks to IVF since the '70s, egg and embryo freezing is by no means a sure path to parenthood. According to a 2014 study by the British Human Fertilization and Embryology Authority, IVF is only successful about a quarter of the time. Women who used their own frozen eggs fared even worsewith 14 percent success rates. The science is pretty straightforward; patients are injected with drugs to stimulate the ovaries, the eggs are then removed to be either fertilized and frozen, or frozen straight away with a process called vitrification. Think of it as a flash-freeze, a massive rapid temperature drop that keeps water crystals from forming and damaging the cell. But every processing stage introduces risk.

Taroli and his husband started out with 18 eggs from their donor. Twelve were successfully fertilized. Eight made it past the three-day inspection. On the seventh day, each ball of 100 cells was tested and scored for chromosomal abnormalities; five were considered viable. One became their son. The other four went into Tank No. 4.

Taroli says he was made aware of these risks, and others that arise during the freeze-thaw cycle, when he and his husband signed their contracts with PFC. Storage in liquid nitrogen, on the other hand, has been considered pretty fool-proof, provided you have enough of it. The tanks are quite simple, just metal welded into an inner and outer tank to create a vacuum sealno moving parts. As long as they stay full, youre fine. Ive been doing this since 1983 and Ive only ever seen one slow leak that was easily rectified, says David Ball, laboratory director of Seattle Reproductive Medicine and a past president of the Society for Assisted Reproductive Technology. Ive never seen a total loss situation.

Frozen Futures


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