A Dutch clinical trial was looking at the potential of Sildenafil or impotence drug Viagra to improve the growth in unborn babies of pregnant women. The study had to be stopped prematurely after the death of eleven babies.
Sildenafil is capable of improving the blood flow. In the clinical trial the team of researchers tried to use the drug to improve the blood flow to the placenta of the pregnant women. These participating pregnant women had poorly developed placenta that caused retardation of overall growth in the fetus. However when administered with Viagra the babies died because the drug causes fatal damage to the lungs of these unborn babies. A detailed investigation is underway to examine the cause of the deaths. Meanwhile authorities have stated that there has been no wrong doing in the trials.
There have been earlier smaller clinical trials in Australia, New Zealand and UK where Viagra had been administered to pregnant women with poorly developed placenta and fetal growth retardation. No harm was seen to the participating mothers in those studies. However Viagra failed to provide any extra benefits in these mothers. Thus in 2010 it was felt that the drug in these scenarios should be used only in clinical trials.
At present there are no treatments for fetal growth retardation due to poorly developed placenta in the mother. These babies are usually born prematurely and have a low birth weight. They have a poor chance of survival. This trial was an attempt to develop a medication that could prolong the gestational period till the baby is well grown and increase the body weight of the baby. This medication could save lives, felt the researchers.
For this study the Dutch researchers included participants who would be recruited for the study up until 2020 and the study would be carried out in 11 hospitals in the Netherlands, one of which is the Amsterdam University Medical Centre. The study began in 2015 and a speculated 350 patients were to be recruited. For this phase of the study 93 women were included and they were all administered Sildenafil. Another 90 women were included in the trial as controls and they were given a placebo drug or dummy.
After delivery it was noted that twenty babies developed lung complications. Of these three were in the placebo group and 17 were from the Sildenafil treated group. Eleven of the sick babies in the sildenafil group died of the lung complications. Eight other babies in the sildenafil treated group died of unrelated complications. Of the three babies in the placebo group that developed lung complications, none succumbed to the illness. Nine babies in the placebo group died due to unrelated causes. An independent committee looked at the study outcome and last week the study was terminated prematurely.
Prof Zarcko Alfirevic, from the University of Liverpool, was part of the UK team. He said that this result from the Dutch study is “unexpected” and more is to be found on the underlying mechanism of the deaths in the babies. “It needs a thorough investigation because the complications were not seen in the two other, similar trials that have already been done in the UK and Australia and New Zealand,” he said.
Wessel Ganzevoort, lead researcher and a gynaecologist said that the last thing they wanted is to harm the patients and they are shocked with the results. He said that their team has informed Canadian researchers who are conducting a similar study and instructed them to stop their research.