Current evidence refutes these myths, including the following. Pelvic and upper genital tract infections are common with intrauterine contraception. 52 Recent studies have consistently shown that it is the patient's lifestyle, rather than IUD use per se, that is associated with PID risk. Moreover, increased risk occurred only during the first 20 days following insertion. Meta-analysis has not shown any benefit from prophylactic antibiotic administration.
Intrauterine contraception works by preventing implantation.
Most evidence now suggests that all IUDs induce a foreign body reaction that is spermicidal, preventing fertilization. Treadway et al found that after artificial insemination, no sperm were present in the tubes of non-medicated plastic IUD users, but sperm were present in the tubes of all control subjects. This finding was confirmed in several other studies. In addition, today's intrauterine contraceptives have other mechanisms of action that prevent fertilization, such as thickening the cervical mucus, reducing sperm motility and creating a barrier to sperm penetration. Women are not interested in intrauterine contraception.