PARIS (AP) — French health authorities are denying claims they concealed a study on a drug used to treat epilepsy that caused birth defects.

Le Canard Enchaine weekly said the health ministry suppressed a study revealing that the drug was prescribed to more than 10,000 pregnant women between 2007 and 2014 while the potential risks for unborn children were known.

The ministry responded Wednesday that the study was launched a year ago and that its initial findings will be presented according to plans on Aug. 24 to parents whose children have been affected by the anti-convulsion drug Depakine, sold in France by pharmaceutical company Sanofi.

A study published in February estimated that there had been around 450 cases in France of children exposed to the drug during pregnancy who had congenital defects.