Dutch hospitals stop trials of Viagra as remedy for growth delay in unborn babies

Edition 30 August 2018, by Bárbara Luque Alanís

On Monday July 23, the Amsterdam hospital UMC, along with nine other Dutch hospitals, immediately stopped a study focused on pregnant women whose babies presented severe growth defects early in the pregnancy. Researchers thought that the drug sildenafil, better known as Viagra, would stimulate the growth of the placenta of pregnant women and thus stimulate the growth of the baby. However, when the drug proved an ineffective remedy for the problem, and even increased infant mortality, the hospital announced the immediate stop of the trials. According to de Volkskrant, each year hospitals see around a hundred pregnant women whose fetuses show an extreme growth retardation. At 22 weeks’ pregnancy, such babies weigh 300 grams, instead of the average 600 grams. This gives them a chance of survival of 40 to 50 percent; the babies who make it, often have serious health issues. Viagra, a drug which offered hope thanks to positive results in previous studies, now appears to do more harm than good. The study showed a higher risk of death among the babies, as well as adverse effects for those babies born alive.

The principal investigator, gynecologist Wessel Ganzevoort, says that alarm bells went off when he was shown figures from all participating hospitals. Infant mortality among the women who took Viagra was much higher and the babies presented a serious lung disease much more often. At the time of termination, the study included a total of 183 participating pregnant women. 93 women received tablets with sildenafil, while 90 women received a placebo. According to news agency NOS, of the 93 babies in the sildenafil group, nineteen died after birth; eleven of them also had a lung disease. Only nine babies died in the placebo group.

Asked about the possibility of lifethreatening lung disease caused by Viagra, Ganzevoort explained: ‘It is clear that it is much more prevalent in the sildenafil group than in the placebo group, so there is a relationship, but in individual cases that is not yet clear. We do not know if the babies would have survived if they had not received the drug’. An analysis by Amsterdam UMC showed that the chance of a disease of the blood vessels of the lungs appears to be greater and the chance of death after birth seems to have increased. The researchers found no positive effect for the children on other outcomes. All adverse effects occurred after birth.

All 183 participating women have been informed of the situation and researchers confirmed that the drug has no direct negative health effects for them. Although the trials have been stopped as a precaution, the data already acquired will continue to be analyzed extensively in the coming period. The development of the children will be closely monitored, in accordance with the original study plan. A previous study by a British research group late last year found no effect of the drug for the fetus. About this, the team leader says: ‘They found no advantages or disadvantages. We now see that the drug does damage, and that’s important news. That is why I hope that patients will not be discouraged by this message, because these kinds of scientific studies are also useful if you show that something does not work or is counterproductive’. He discussed how this study will help to prevent products coming onto the market that may harm patients. The trials were intended to thoroughly investigate the effect and the safety of the substance, while the adverse effects that have now been found were unknown to date. Researchers expect that the use of Viagra for this purpose will stop worldwide, and plan to communicate the results of this study to gynecologists all over the world.

According to Cees de Heer of the CCMO (Central Committee on Research Involving Human Subjects), once a year an investigation is stopped for safety reasons. Every year in the Netherlands about 1700 medical-scientific studies start; new medicines are tested in about one third of these.