Protecting the Developing Fetus
Infection during pregnancy may impact the natural protection of the fetus, according to new research by a U of T professor.
Professor Stephen G. Matthews and his team found evidence that bacterial and viral infections may weaken the placenta's ability to reduce transfer of certain drugs and environmental toxins from the mother to the developing fetus.
“Intrauterine Infection is quite common during pregnancy, and we know that it's present in about 40 percent of preterm births,” says Matthews, a professor of physiology, medicine and obstetrics/gynecology.
Matthews' team analyzed placental tissues from early in pregnancy and from women who delivered by planned cesarean section. They simulated infections in the tissue to test how viruses and bacteria affect two key transporters that can reduce transfer of potentially harmful substances across the placenta. They found that in the particularly sensitive first trimester, bacteria decreased the expression of both transporters.
Theoretically, this could allow certain therapeutic drugs – ones that are thought not to cross the placenta – to reach the fetus.
This is the first time that such tests have been performed in vitro in human tissue at different times in pregnancy.
Matthews' findings should help scientists understand more about how the fetus is protected during pregnancy. By understanding the factors that weaken the shield, researchers can help to guard against it. That knowledge could lead to greater protection of mother and fetus – as an example, for women who are diagnosed with cancer during pregnancy and require life-saving drug treatment.
“Potentially we could find a way to switch on the barrier, protect the fetus and treat the mother with a drug she might not otherwise be able to use,” says Matthews, who is also Director of Research for the Fraser Mustard Institute for Human Development. “The more we understand about the barrier the more we can work with it.”
Matthews published his research May 8 in a paper, Impact of Bacterial and Viral Challenge on Multidrug Resistance in First- and Third-Trimester Human Placenta, in The American Journal of Pathology.
