The number of young people having unprotected sex in the West has risen sharply over the past two years, a survey said Monday, with health professionals concerned the safe sex message is falling on deaf ears. The study by the Parenthood Foundation showed particularly sharp increases among sexually active teenagers in the United States and in European countries such as France who were failing to use contraception with a new partner. In the United States, the percentage rose from 38 percent in 2009 to 53 percent now, while France saw an increase from 19 percent to 40 percent. The survey to mark World Contraception Day also discovered that Thailand is a particular cause for concern because as many of 62 percent of young Thais have had unprotected sex with a new partner. But the figure was above 50 percent in countries as diverse as China, South Korea, Norway and Estonia. The study highlights that across Europe, the Asia-Pacific region, Latin America and the United States, the most common reason for not using contraception is a lack of preparedness for sexual activity. Up to a third of young people in those regions said they did not have any form of contraception available when at the time of intercourse. Jennifer Woodside of the International Planned Parenthood Federation said: "What the results show is that too many young people either lack good knowledge about sexual health, do not feel empowered enough to ask for contraception or have not learned the skills to negotiate contraceptive use with their partners to protect themselves from unwanted pregnancies or STIs (sexually transmitted infections)." The survey involved 5,426 young people in 26 countries in Asia-Pacific, Europe, Latin America and United States, as well as 600 people in Egypt, and was conducted between April and May this year. It concerned people aged 15 to 24, although it included respondents up to the age of 30 in Egypt. It was funded by German pharmaceuticals giant Bayer.