How long will it take for chlamydia to cause permanent damage ?

Not long!: Tubal damage can be severe when a woman has smoldering chlamydial infection in her genital tract and lead to infertility due to tubal occlusion/malfunction. This used to be a cause for permanent sterility, but not anymore; art (assisted reproduction technology) advances now pretty much guarantee that women with these problems can get pregnant and have healthy babies with ivf tubal bypass.