As well as being used as treatment for erectile dysfunction, Viagra is being looked at to be used in a number of other medical settings, including the treatment of fetal growth restriction (FGR). This is a condition in which babies don’t grow properly in the womb. 

However, following a recent study conducted by a group of scientists at the University of Manchester, it seems Viagra may not be as versatile as they were hoping. Because Viagra enhances blood flow it was seen as a potential choice of treatment for FGR. However, following a recent study involving mice, no real improvement was seen in terms of fetal growth, only a high blood pressure level when the pups got older. So, is the drug all it’s cracked up to be?

Perhaps not in this circumstance.

Almost 3 in every 100 pregnancies are affected by FGR. Babies that are affected and survive are more likely to suffer from developmental issues and health concerns such as diabetes and heart disease. Most of these FGR cases are caused by poor functioning of the placenta. As the blood flow becomes restricted, so does the transferring of nutrients from mother to baby. There are currently no treatments in place for FGR. For the baby to have any chance at survival, the only option is to deliver the baby early and care for it as best as possible outside of the womb. 

The results of the study conducted by the Manchester team were published in the American Journal of Physiology – Heart and Circulatory Physiology. Around the same time, an international clinical trial of Viagra and its affects on severe human FGR took place, called STRIDER. It too found no significant link between the taking of Viagra and the improvement of FGR. Unfortunately, the STRIDER trial was ground to a halt as 11 babies whose mothers were directly involved in the study and used Viagra died from lung complications. However, neither the UK-Ireland nor New Zealand trials saw any similar results.          

Going back to the Manchester study, more than 90% of baby mice whose mothers were fed Viagra while pregnant saw a hike in their blood pressure to a range similar to that of a high blood pressure level seen in humans. Female mice also saw a gain in weight after a birth and a slight reduction in their glucose intolerance after just 8 weeks. 

“The evidence from this study and others suggest that caution should be used for the use of Viagra in Fetal Growth Restriction,” said Dr. Mark Dilworth, leader of the study. “Our study suggests there may be long-term risks associated with its use in mice and importantly, there is a lack of beneficial effect in recent human clinical trials.” 

So, it seems, there is still a lot of work to be done in order to find a suitable treatment for FGR. And, it’s “important to continue to conduct studies which look at longer term impacts of giving medication during pregnancy as there is surprisingly little research on this,” concluded Dilworth.