Carmen Chai
Global News
In vitro fertilization (IVF), freezing eggs and embryos, and transplanting a single sperm precisely into an egg. The medical community has made major strides in the science of baby-making and reproductive health in just a few decades.
Dr. Robert Casper remembers opening the first IVF clinic at the University of Western Ontario in London, Ont.
It was 1984. Since then, the University of Toronto professor and Mount Sinai Hospital scientist watched fertility science continuously refine and improve.
“The whole field has been advancing tremendously quickly compared to a lot of other fields in obstetrics and gynecology. It was a very exciting place to be,” Casper told Global News.
He’s now scientific director at Trio IVF in Toronto.
In the 1970s and ’80s, treating fertility issues was rudimentary. If fallopian tubes were the problem, women were operated on. If ovulating was the culprit, doctors turned to only a handful of drugs.
“That’s all we had. We knew [IVF] would be a big development because we had nothing else of that proportion. It was very obvious this was something that would revolutionize fertility,” Dr. Al Yuzpe, who’s been working in the fertility field for the past 47 years, told Global News.
READ MORE: 7 fertility myths and misconceptions Canadian women need to know
He also helped to open the fertility clinic at London Health Sciences – now he’s opened Olive Fertility in Vancouver.
The experts walked Global News through a series of breakthroughs that have overcome barriers to fertility.
IVF: The first IVF baby was born in 1978 in England. Louise Brown’s parents became the first couple to successfully undergo IVF, but scientists were working tirelessly across the United States, and Sweden, too, Casper said.
“It gave us another avenue for treatment,” Yuzpe explained. Suddenly, clinics opened up around the world.
The first IVF clinic in Canada opened in Quebec City, followed by Vancouver, Toronto and London, he said.
IVF is the process in which doctors take eggs from the ovaries and mix them with sperm in a laboratory dish. Millions of babies have been born through IVF since then.
Tweaking and refining IVF: Since IVF took off, it’s only gotten better. Keep in mind, IVF clinics started from scratch: they didn’t have medication to control ovulation, so doctors had to collect women’s urine every three hours. Once a surge in hormones was recorded, she’d book an egg retrieval about 24 hours later – even if it meant doctors were conducting the procedure at 2 a.m.
There was no ultrasound in those days, so doctors even did retrievals in the operating room with the help of a telescope and a needle through the abdominal walls.
Now doctors rely on an ultrasound probe linked to a screen with a grid that guides them to the ovaries.
“We get a lot more eggs because you can see them all,” Casper said. Medication brought the control into doctors’ hands: they could decide when women would ovulate and could even boost how many eggs they release for retrieval.
ICSI: Intracytoplasmic Sperm Injection – more commonly known as ICSI – was a game-changer once the 1990s rolled around.
It was developed in Belgium – in this case, doctors could take sperm from men grappling with fertility issues, such as a low count or weak sperm, and inject a single sperm into an egg. Doctors would ensure the egg was fertilized – at the time, success rates were estimated at 50 to 80 per cent, Yuzpe said.
“This was the first treatment that really made a difference for men and fertility. It’s still really the only treatment,” Yuzpe said. Keep in mind, about 40 per cent of fertility issues are linked to men.
Before ICSI, if men didn’t have strong or enough sperm, they had to rely on donor sperm.
Freezing eggs, sperm and embryos: Egg, sperm and embryo freezing received a major tune-up in the early 2000s.
Egg cells are the largest cells in the body – because of their size, freezing is a “real problem” because their water content leaves ice crystals that tamper with, and tear apart the cells inside.
Enter vitrification – in this process, scientists race through the period of ice crystal formation, turning the water into glass, not ice, Casper said.
Slow freezing takes about two hours to freeze an egg and the egg is cooled gradually. With vitrification, the temperature is reduced by about 1 C per minute until the egg is frozen. The temperature continues to drop to about -7 C. Then the egg is put in liquid nitrogen.
“Now we vitrify everything and the survival rate is close to 90 per cent. Slow cooling was about 70 per cent,” Casper said.
Like birth control, vitrification changed the landscape for women. With the pill, they could stave off pregnancy. With vitrification, women could freeze eggs so that if they wanted to get pregnant later on in life, they had access to them.
Women dealing with cancer, chemotherapy or other conditions that would affect their reproductive health were granted access to vitrification. Now it’s available to most women, the experts say.
“It became an issue for social reasons – women were delaying childbearing, they didn’t have a male partner, or they wanted to preserve their fertility. Now they are able to freeze their eggs,” Yuzpe said.
IVF screening: In vitro fertilization reached another level of sophistication through screening and time-lapse photography. Now, doctors use techniques such as embryonic chromosomal screening and cell division monitoring.
With screening, doctors can test embryos if patients carry hereditary diseases, such as cystic fibrosis or muscular dystrophy and choose the healthiest embryos for transfer.
Using time-lapse imaging, doctors can even watch the progression of embryos in the lab to decide which are healthiest for implantation.
Single embryo transfer: There’s a reason why there are fewer twins and triplets born out of IVF – the technology behind it has improved so doctors can rely on single embryo transfers.
Doctors can use a frozen egg and frozen sperm, wait for five days to monitor the quality of the embryo. Before, they would only wait about two or three days after fertilization, but this extra time matters.
“It completely eliminates the risk of twins. There’s no more pressure to put more than one embryo back. Before if you weren’t sure you’d put two or three back,” Casper said.
Through single embryo transfer, Casper says babies are born bigger, and with fewer complications.
What’s next for fertility therapy? The latest frontier in fertility is carving out more space for people who cannot have babies through uterine transplants and even “three-person babies.”
These technologies aren’t for the general population. The United Kingdom is the only country to allow three-person babies, for example.
In September, scientists said the world’s first three-person baby was born. The child was at risk of inheriting DNA for Leigh syndrome, a severe neurological disorder that usually kills within a few years of birth.
The technique involved removing some of the mother’s DNA from an egg, and leaving the disease-causing DNA behind. The healthy DNA was slipped into a donor’s egg, which was then fertilized. As a result, the baby inherited DNA from both parents and the egg donor.
