A quarter of couples experience infertility despite regular sex, according to the French national research institute INSERM. The reasons include exposure to pollutants, endocrine disruptors, trying for a child later on in life, smoking and obesity. But in more than 15 percent of cases, the cause of the infertility remains unconfirmed. France's health minister has decided to take action by putting together a working group to better understand the issue and suggest changes by the end of the year. FRANCE 24's Eléonore Vanel and Camille Nedelec report.