Fifty genes: which are critical?

IVF research could lead to improved success rates

Cole Garside

Highlights from our latest Rethink issue:

In vitro fertilization is the last hope for many couples struggling to get pregnant. Even then, the procedure has a nearly 60 per cent failure rate. Canadian researchers are hoping to improve that by studying genes in the uterine lining to understand why sometimes a uterus accepts an embryo, while at other times it doesn’t.

Until recently, examining that process meant biopsying the uterine lining, an invasive procedure that couldn’t be done while a woman was undergoing IVF treatment. Researchers at the Mount Sinai Centre for Fertility and Reproductive Health in Toronto have found a new way to extract the genetic material by using a tiny catheter inserted through the cervix to remove a small amount of uterine fluid.

That’s the easy part. They now have to sort through the 50 different genes that may or may not be responsible for the process. “It’s hard to know if they’re all absolutely necessary or just innocent bystanders,” says Dr. Ellen Greenblatt, the centre’s medical director. The research could lead to new techniques or medications that improve the success rate both for women undergoing IVF and those hoping to conceive naturally, but who have suffered multiple miscarriages. But first, says Greenblatt, “we need to understand the basic biology.”


Birth control pill for the brain

Imagine if you could turn fertility on and off like a light switch. New research into the brain’s central role in human reproduction promises to do just that. Scientists have long known that a protein called Kisspeptin plays a critical role in puberty in all mammals. But last month, Allan Herbison’s team at the University of Otago, New Zealand, published research showing they had found the exact place in the body where Kisspeptin was working: a small group of neurons in the brain known as GnRH. They took mice that had failed to go through puberty and injected Kisspeptin into these neurons. The result was “fertility comes back, puberty comes back, everything is completely normal,” says Herbison.

The discovery offers new hope for infertile couples, since nearly a third of infertility cases are likely due to problems with brain signalling. It’s also given rise to the prospect of a birth control pill for the brain. Current birth control pills work by flooding a woman’s body with hormones to stop ovulation. “It would be better to go in and much more selectively turn off fertility in one little select group of neurons in the brain,” Herbison says. Indeed, pharmaceutical companies are already feverishly working on such a pill, while treatments that could use Kisspeptin to help women undergoing in vitro fertilization improve their chances of success are as close as five years from becoming a reality.

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