The American Academy of Pediatrics is urging sexually active teenage girls to use IUDs or hormonal implants. Condoms are the most common form of birth control among teenagers, but they are often the least effective of contraception options. Teenagers have to remember to regularly use condoms or take contraceptive pills, as opposed to an IUD or a hormonal implant, which is nearly 100 percent effective for three to 10 years once it is inserted. Although it usually costs hundreds of dollars to get an IUD because it needs to be inserted via a formal medical procedure, it is less expensive in the long run than over-the-counter condoms or prescription birth-control pills, said Dr. Mary Ott, an adolescent medicine specialist and associate pediatrics professor who was the lead author on the updated policy. Teens were still urged to use condoms to prevent sexually transmitted infections. “All methods of hormonal birth control are safer than pregnancy,” said Ott. The updated policy was published Monday in Pediatrics.