By Katherine Gombay
It’s not every day that a conversation moves from mouse sperm to global population issues. But for Bernard Robaire, a professor in the Departments of Pharmacology and Therapeutics and Obstetrics and Gynecology, who works on male fertility, the two are at least loosely connected.
Robaire first became interested in the field as a post-doc student working on developing a male contraceptive. He continues to do research in the area today, driven as much by moral convictions as he is by scientific interest.
“Western society has a huge obligation to develop methods of birth control that are going to be acceptable to different populations with different cultures around the planet. We can’t afford 11 billion people on this planet. And there should be opportunities for both men and women to exercise safe family planning.”
But developing an effective form of birth control for men is more challenging than it is for women. Where there is just one egg a month, it’s relatively easy to develop drugs that misalign a woman’s cycle so that ovulation doesn’t occur, explained Robaire. “But when you’re dealing with 100,000,000 sperm a day, it is extremely difficult, not impossible, but really difficult.”
One of the problems with the drugs that have been developed so far, which depend on a combination of steroids to suppress the development of sperm, is that they work much better, for reasons that are still poorly understood, for Asian men than they do for Caucasians or for men of African origin. This is just one of the reasons that the big pharmaceutical companies are currently pulling out of research into male contraceptives, explains Robaire. It’s a decision which disappoints him and which he describes as being made in the boardrooms and not having a scientific foundation.
“With contraceptives, you’re giving a drug to tens of millions of people who have nothing wrong with them, so they don’t expect any side effects. And the drug has to work perfectly,” he said. “If you have an anti-cancer drug and you get some side effects, it’s considered normal, and if you get 50 per cent cure you’re happy. But if you have a contraceptive and you have 90 per cent success, it’s a disaster.”
Effects of chemotherapy
One group that seems not to have to worry too much about using contraceptives, at least initially, is men who have undergone chemotherapy. As the numbers of young men who are successfully treated for testicular or other kinds of cancer grow, Robaire has started looking into the effects of chemotherapy on male fertility. The results of his studies are both encouraging and intriguing.
Robaire and his colleagues have discovered that within a year of chemotherapy between 50 and 75 per cent of men will produce sperm, though their sperm count is decreased. It may take a man much longer to impregnate his partner, and even though the rate of spontaneous abortion is higher, the children who are born appear to be fine.
Robaire cautions, however, that the numbers of children born in this situation are so limited at this stage (in the low thousands) that a much larger sample (between 50,000 and 200,000 people) will likely be needed for there to be statistically significant results.
The intriguing results come from Robaire’s research using rats and mice. His team has discovered that although sperm are damaged by chemotherapy, there appears to be a repair mechanism in the female egg that compensates for the damage to the sperm and allows for the birth of healthy offspring. “It seems that there is activation of a DNA repair machinery, but we haven’t figured out which genes are involved or how they are turned on,” he said.