<h4>Background</h4>Our goal was to investigate immunoglobulin G1 (IgG1) and immunoglobulin G3 (IgG3) antibody responses to Chlamydia trachomatis proteins Pgp3 and Hsp60 in males of subfertile couples and to explore the association of these antibodies with semen parameters and male factor infertility.<h4>Methods</h4>Serum samples were collected from 256 male partners of subfertile couples. Here, IGHG3 is linked to Infertility.