Since the 1980s, the incidence of infertility in Canada has doubled and today, more than 15 percent of Canadian couples—one in six—have difficulty getting pregnant.Footnote 1 Researchers have identified a number of potential factors behind this trend, with exposure to toxic substances in the environment among the most significant.Footnote 2
At Health Canada's Food Directorate, where she specializes in developmental and reproductive toxicology, Research Scientist Dr. Anne Marie Gannon explains that we can be exposed to these chemical toxicants in a number of ways, including in air, water, soil and foods.
"In my lab, we're especially interested in endocrine disrupting chemicals," says Dr. Gannon. "These chemicals can have negative effects on fertility by interfering with hormone pathways and ovarian function, among others."
Invisible symptoms
With funding support from the Government of Canada's Genomics Research and Development Initiative (GRDI), Dr. Gannon is leading a research project aimed at finding a way to detect toxicant-induced infertility in women at an early stage—before the damage to reproductive ability becomes irreversible.
"The problem is that the harm done by these chemicals can happen silently over a period of years," says Dr. Gannon. "There are no visible symptoms, and by the time ovarian function has been affected to the point where it can be detected by existing diagnostic tools, it can be too late to do anything about it."
Genomics enables new look at old research
Dr. Gannon and her colleagues at Health Canada, Drs. Genevieve Bondy, Ivan Curran and Santokh Gill, are using advanced genomics technologies to examine tissue and blood samples that have been retained from animal-based testing done in the past.
"We're looking for changes in genomic biomarker levels that correlate to the chemically-induced ovarian toxicity found in the traditional testing done on these animals," explains Dr. Gannon. "The goal is to identify a number of these biomarkers so that, in future, a method could be developed to screen for a panel of these markers in a blood sample and determine whether they had been altered in ways that indicate exposure to toxicants of concern."
Exciting potential
While still in the beginning stages of the project, and the relevance of these results from animal models to humans yet to be fully determined, Dr. Gannon is confident that the GRDI-funded research will result in a significant step toward a reliable blood test that would detect toxicant-induced infertility in the early stages—when steps can be taken to mitigate the risk of permanent damage.
"Beyond the considerable emotional and physical effects of infertility, it can also represent a significant financial burden for those who may choose to pursue options such as in vitro fertilization," says Dr. Gannon. "Early detection could play an important part in reducing those kinds of impacts. A simple blood test would be a dramatic improvement over existing, very invasive screening tests for environmental toxicant-induced infertility."
Contributing to enhanced public health
Through publication in journals and presentations at scientific conferences, Dr. Gannon's GRDI research has attracted the interest of researchers in other countries, including Dr. Jodi Flaws, Professor of Comparative Biosciences and Director of the Flaws Reproductive Toxicology Laboratory at the University of Illinois.
"There's no question of the importance of the work Dr. Gannon and her team are doing, and the importance of public funding for this research, such as that being delivered through the GRDI program," says Dr. Flaws. "Infertility is a major public health issue. There are chemicals that we're exposed to on a daily basis. Identifying these markers of potential infertility opens the door to early intervention to reduce exposure or initiate treatment so infertility doesn't happen. We would also be able to better monitor or predict whether a certain toxic exposure could lead to infertility."