A new study suggests that metformin - a drug commonly used to treat diabetes and considered safe for use in pregnancy - has potential to prevent or treat preeclampsia, a pregnancy complication that can be life-threatening and currently has no cure.
The researchers - from the University of Melbourne and Mercy Hospital for Women, also in Melbourne, Australia - report their findings in the American Journal of Obstetrics and Gynecology.
The journal's Editor-in-Chief Dr. Roberto Romero says there should now be further research and clinical trials of metformin as a treatment for preeclampsia and possibly other pregnancy complications.
The condition arises when insufficient blood supply to the placenta causes it to release toxins into the expectant mother's bloodstream, leading to high blood pressure and possible damage to the brain, liver, kidneys and other organs.
Preeclampsia affects 5-8% of all pregnant women and is a leading cause of maternal death. Around the world, the condition kills around 500 women every day.
In severe cases of preeclampsia, the only treatment is to deliver the baby early, which raises the risk of disability and death of the infant.
Metformin has long been used to treat diabetes in both non-pregnant and pregnant patients, in whom it is considered safe to use.
In recent years, studies have also suggested metformin may have other benefits. For example, a study published in 2014 found metformin could extend lifespan in both diabetics and non-diabetics. It has also been suggested that metformin has anti-cancer properties, although a study reported earlier in 2014 urged caution in accepting this conclusion as it found metformin's effect on tumors is not necessarily what has been assumed.
'Metformin improves features of endothelial dysfunction'
Over recent decades, biologists have discovered that in preeclampsia, the placenta releases two toxins into the mother's bloodstream - sFlt-1 and sENG. These disrupt endothelial cells - the cells that form the lining of blood vessels - raising blood pressure and causing organ failure.
However, there are currently no drugs or treatments available that can safely reduce the effect of these toxins in pregnancy.
In the new study, the researchers ran a series of experiments using human tissues and cultured cells to examine the effect of metformin when the two toxins are released.
They found that metformin not only reduces production of the two toxins, but it appears also to help heal injured blood vessels; the authors note that metformin "improved features of endothelial dysfunction relevant to preeclampsia."
The results also suggest that metformin improves "vasodilation" - the dilation of blood vessels, which in turn decreases blood pressure - and it induces "angiogenesis," the formation of new blood vessels. The authors conclude that:
"Metformin has potential to prevent or treat preeclampsia."
Dr. Romero says the findings may also improve treatments of other pregnancy complications such as fetal death, fetal growth restriction and premature labor, because problems with blood vessel formation are also a feature of these conditions.
He says there is now an urgent need to review all randomized clinical trials that have involved pregnant women taking metformin, and for new randomized trials to be devised specifically to test whether metformin can be effective in preventing preeclampsia and other pregnancy complications.
Meanwhile, Medical News Today recently learned of a study that finds rates of preeclampsia have risen dramatically in the US over the last 2 decades. The researchers say the finding highlights the importance of identifying an effective treatment to prolong pregnancy and treat preeclampsia.