There are no reliable national surveillance systems that measure women requiring treatment for PID. This measure, based on data from NSFG, is used as a proxy.
PID is a subjective diagnosis made by physicians. Laparoscopy is required for a definitive diagnosis of PID. The data from the NSFG are self-reported and therefore may not be accurate, particularly due to the unknown prevalence of asymptomatic or subclinical PID.
More than 50 percent of all preventable infertility among women is a result of STDs, primarily Chlamydia and gonorrhea. Because most infected women and at least one half of infected men have no symptoms or have such mild symptoms that they do not seek medical care, many infections go undetected and are not reported or counted. Untreated Chlamydia and gonorrhea infections can cause severe and costly reproductive and other adverse health consequences, including pelvic inflammatory disease (PID), which can lead to infertility. Between 10-20 percent of females with untreated Chlamydia infections develop PID, and 20 percent of those may become infertile.