A potentially dangerous sexually transmitted disease that infects millions of people each year is growing resistant to drugs and could soon become untreatable, the World Health Organization said Wednesday.

The U.N. health agency is urging governments and doctors to step up surveillance of antibiotic-resistant gonorrhea, a bacterial infection that can cause inflammation, infertility, pregnancy complications and, in extreme cases, lead to maternal death. Babies born to mothers with gonorrhea have a 50 percent chance of developing eye infections that can result in blindness.

"This organism has basically been developing resistance against every medication we've thrown at it," said Dr. Manjula Lusti-Narasimhan, a scientist in the agency's department of sexually transmitted diseases. This includes a group of antibiotics called cephalosporins currently considered the last line of treatment.