Why can untreated chlamydial infections cause female sterility?

Untreated chlamydial infections can lead to female sterility primarily by causing pelvic inflammatory disease (PID), an infection of the upper reproductive tract.12

When Chlamydia trachomatis is left untreated, it can spread to the fallopian tubes, resulting in a condition known as salpingitis. This infection triggers inflammation that leads to scarring and blockage of the fallopian tubes. Because these tubes serve as the essential passageways for the egg and sperm to meet, their obstruction prevents fertilization and can result in permanent infertility.132

Furthermore, this damage increases the risk of ectopic pregnancies, where a fertilized egg embeds outside the uterus, posing significant health risks. Given these serious long-term consequences, timely diagnosis and antibiotic treatment are critical to preventing reproductive damage.13