By Jennifer Xu, Magazine Editor
Published September 4, 2012
We live in an age of mechanical production. OnStar, rather than the North Star, guides us home. Texts determinedly buzz at our legs wherever we walk. Technological gadgets have insinuated themselves into our personal, professional and internal lives.
If you were infertile, would you consider performing in vitro fertilization with a frozen egg?
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So it should come as no surprise that we also live in an age of mechanical reproduction. That's right, the most intimate biological process is now online and open for business.
Sandwiched between Craigslist calls for “$$$ Exotic Dancers $$$” and “Happy Finnish Massages” are multiple inquiries for college-aged egg donors. In the 1970s, one of these eggs would be joined with a sperm in a petri dish and clumsily fumble into its embrace. Sometimes, this process — called IVF, in vitro fertilization — created a baby. Other times, it didn’t.
But now, these eggs can be frozen, hermetically sealed in liquid nitrogen until revived from their cryogenic freeze to be injected into a hopeful mother’s uterus. You could do whatever you wanted with these eggs — save them, implant them, study them, throw them out. Yet, as new technologies in assisted reproduction glide inevitably onward, the question remains: what implications will this have on donors and the recipient couples?
Fresh vs. frozen
There’s no better adjective to describe Michael Mersol-Barg’s fertility clinic in Birmingham, Mich. than clean. A pitcher of ice water and a tin of biscotti cookies welcome prospective patients to the brightly-lit space. Tidily stacked atop the waiting room chairs are magazines emblazoned with proud parents clutching babies, their skin as smooth as eggshells.
A floor below, nearly 20 different eggs are suspended in deep-freeze, tightly packed in liquid nitrogen tanks at temperatures nearly 200 degrees below zero. Some of these eggs are more than three years old, waiting for the day their cell walls will be cracked open by a sperm cap and implanted into a prospective mother’s womb.
Pregnancy with a frozen egg is a relatively new development in the field of assisted reproductive technology. Rather than going through the interminable trials (and failures) of obtaining eggs from a fresh donor, infertile couples can select a pre-frozen egg from Mersol-Barg’s egg bank — the only one of its kind in the state of Michigan — and begin IVF immediately.
Bill and Julie VanDerworp, a couple struggling with infertility from Commerce Township, Mich., recounted their struggle to obtain fresh oocytes.
“It’s a numbers game, completely,” Bill said.
For every donor they selected, the VanDerworps had to wait until the college-aged women were available for a summer break, then gradually sync their ovulatory cycles to the recipient mother and wait with bated breath to see if the embryos would take.
The first donor produced 13 eggs at the outset. Out of those, 11 were viable for fertilization. But by the time the embryos were ready for implantation — about five days after the eggs were mixed with sperm — only two of the original 13 remained.
The two embryos implanted into Julie's uterus didn’t take and she suffered a miscarriage two weeks into the pregnancy.
Another donor only produced four or five eggs at retrieval, so it wasn’t worth going through the rest of the process. But the VanDerworps still had to incur all the cost of her medical bills and infertility drugs — about $25,000 per cycle.
“Every time you pick a girl for fresh, you’re out of pocket,” Bill said. “But it might work, it might not.”
Ice without the freezer burn
The newest technology in the field — oocyte vitrification — can prevent such inconsistencies from happening. Now, as soon as the eggs are retrieved from a willing donor, they’re immediately frozen, stored in an egg bank and thawed at the recipient couple’s convenience. Egg freezing offers a guarantee that those oocytes selected for IVF are viable, increasing the chance of pregnancy.
Donor sperm have been frozen and thawed for decades. For lack of a better term, they don’t get freezer burn. After the sperm are collected, they can be quickly dehydrated and popped into a freezer, ready to be thawed at any time.
But the difficulty with freezing the sperm’s female counterpart — the oocyte — is that it is inundated with water droplets. Water in its liquid form is innocuous. But when it is frozen, ice crystals form, and these crystals can be deadly to the developing baby.
“Crystals, like snowflakes, can become jagged,” said Marsha Parker, an embryologist at Mersol-Barg’s fertility clinic.
The knife-like tips of the ice crystals can destroy the egg’s interior structure, slashing through the floating chromosomes. And pregnancy via a damaged egg can result in catastrophic after-effects — most commonly, miscarriages.
Enter the process of vitrification.