The study - which started in 2015 and involved 11 hospitals - was created to look at possible beneficial effects of increased blood flow to the placenta in mothers whose unborn babies were severely underdeveloped.
Half of the 183 mothers in the trial had been treated with SIL, while the other half were treated with a placebo. "All the women concerned are accompanied to the extent possible by the doctors involved in the study".
It sometimes occurs because the mother has high blood pressure, uncontrolled diabetes or a condition called preeclampsia, he added.
But an independent committee which was supervising the research realised that more of the babies than expected had been born with issues with their lungs.
Seventeen of those women's babies developed lung problems and 11 have died as a result. Three others were born with a lung condition.
"As a precautionary measure, we have paused recruitment into our trial, until we have an opportunity to gain further information". But they also found no benefit.
"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 statement read.
Ganzevoort, a gynecologist at the Amsterdam University Medical Centre, said he has notified Canadian researchers conducting a similar study, and they have temporarily stopped their research.
Can pregnant women safely take anxiety medication? . Seventeen babies developed lung problems, and 11 died. Nine other babies born to women in the control group died of unrelated problems.
He told NOS that 10 to 15 women who took part do not yet know what the outcome will be for their baby: some are still pregnant, and a number of parents have babies in intensive care.
Mr Kumar said a decision on the future of the Queensland study would be decided within a fortnight and, in the meantime, they have stopped recruiting mothers for their research.
Pills of the drug Viagra (L) made by Pfizer, are shown in this file photo in NY. Spokeswoman Dervila Keane wrote in an email Tuesday that the research is "an investigator initiated study and Pfizer have no involvement in the trial".
In a statement, Pfizer, the makers of Viagra, said they were not involved in the trial, "and neither funded nor provided product for the trial".
Prior to the experiments, the growth of each of the unborn babies was found to be limited and the prognosis viewed as poor. That poses a hard dilemma for doctors: Inducing birth too early increases the risk of complications, but waiting too long could lead to developmental anomalies or stillbirth.
Previous clinical trials in the U.K., Australia, and New Zealand did not find any evidence that the intervention was harmful. The Dutch researchers have advised women in the United Kingdom trial to heed the results of their study. "We will continue to work with the sponsor to determine next steps, including the suspension of the trial, if necessary".
"This finding in the Dutch study is unexpected", Zarko Alfirevic, a professor at the University of Liverpool and one of the authors cited in a similar United Kingdom study, told the BBC.
"Viagra is indicated for the treatment of the symptoms of erectile dysfunction in adult men (aged 18 years and over)".
Patients had even heard about the study and had asked him to prescribe it, he said.