 From at least the 18th century , condom use was opposed in some legal , religious , and medical circles for essentially the same reasons that are given today : condoms reduce the likelihood of pregnancy , which some thought immoral or undesirable for the nation ; they do not provide full protection against sexually transmitted infections , while belief in their protective powers was thought to encourage sexual promiscuity ; and , they are not used consistently due to <unk> , expense , or loss of sensation . 
