Grant: Operating Grant

Premature birth is the major problem in modern Obstetrics. In Canada, approximately 9 percent of babies are born prematurely. These babies account for 75 percent of all newborn deaths and for the majority of disabilities such as cerebral palsy, mental retardation, blindness, and learning disabilities that persist through childhood and adult life. There is no evidence that our current treatments to prevent preterm birth result in healthier newborns. Obstetricians often attempt to stop premature labour by using muscle relaxants to stop premature labour. Unfortunately, these drugs not only affect the uterus but also the muscles of the mother's arteries. This causes low blood pressure that can have very harmful effects for both mother and baby. We have recently discovered that the muscle cells of the uterus contain a unique mechanism that regulates contractions. Since this mechanism is not present in the muscle cells of arteries, we propose that we can use drugs to selectively prevent premature contractions of the uterus without lowering mother's blood pressure or causing other significant side effects. Several drugs have already been developed to inhibit this unique mechanism in the uterus. We propose to investigate these drugs in uterine muscle and in maternal arteries using tissues from pregnant rats as well as tissues donated by women with normal pregnancies who are having a cesarean section. We also propose to test these drugs in an animal model (rats) to see if they will prevent normal or premature labour. These experiments will ensure that the drugs will effectively stop the uterine muscle from contracting and have no effect on arterial tissues. Our results could provide the evidence needed to test these drugs in clinical trials with pregnant women who are either at risk of premature labour or in whom premature labour has already started. Finding a successful method to prevent premature birth would be of tremendous benefit not only in Canada but globally.