Early intrauterine growth restriction (IUGR) is a rare condition where the baby does not grow properly inside the womb. A research team based out of UBC is investigating whether sildenafil, commonly known as Viagra, could be an effective treatment for this devastating condition that begins early in pregnancy.
Kenneth Lim
The STRIDER (sildenafil therapy in dismal prognosis early-onset intrauterine growth restriction) trial was approved by Health Canada this month and the team is coordinating efforts to recruit participants from across Canada. Kenneth Lim, Head of the Division of Maternal-Fetal Medicine program at UBC and a doctor at BC Women’s Hospital + Health Centre, describes how he and his colleagues hope to find a new treatment option for this condition.
What is early intrauterine growth restriction (IUGR) and how does it put the baby at risk?
Early IUGR is a condition in which the baby doesn’t grow as well as we would like inside the womb. There are many different reasons why the baby may not grow but in some cases, it is because the placenta is not able to supply enough nutrition to the baby and the baby slows down its growth to match the supply. In these cases, the risk of stillbirth goes up.
If the problem started early in the pregnancy and the deprivation is severe enough, women and physicians are faced with a very difficult choice to leave the baby in the womb and risk stillbirth or intervene and deliver the baby early, sometimes before 27 weeks. The more premature the baby is, the higher the risk of death and disability. Women and their babies are in a desperate situation when we have to make this difficult choice.
What do you hope to learn from this trial?
We don’t have any proven treatments for early IUGR, which is why we need to evaluate potential therapies like sildenafil. Sildenafil improves blood flow outside pregnancy so we suspect that it could improve blood flow, and thereby nutrition, to the baby in pregnancy. If using sildenafil means that the baby can stay in the womb for longer, it can greatly increase survival and improve outcomes.
We’ve already done a small study that has shown promising results. Growth of the babies has appeared to improve and no harms were identified, although the number of babies studied was small. Other supportive research studies have been published by other groups.
How can women participate in this trial?
The STRIDER trial has been approved by Health Canada and we are recruiting participants from across Canada. We are asking women or their doctors to contact us if they would like more information about participating in the trial at: STRIDERCanada@cw.bc.ca.
The research team is co-led by Dr. Lim and Peter von Dadelszen, Academic Head of Obstetric and Gynaecology at St. George’s, University of London, U.K., who designed the trial. The research team includes Laura Magee, Professor of Maternal Medicine at St. George’s, University of London, and Sayrin Lalji, Clinical Associate Professor of Maternal Fetal medicine at UBC and BC Women’s Hospital + Health Centre.
The STRIDER trial has received funding from the Canadian Institutes for Health Research.