Chlamydia is a common sexually transmitted disease caused by a bacteria called chlamydia trachomatis which can affect both sexes. In some pregnancies, this disease can cause premature labor among women. Moreover, it can cause chlamydia-related diseases among babies such as eye and respiratory tract infections. It is also a leading cause of early infancy pneumonia and pink eye or conjunctivitis. Therefore, Chlamydia is the sexually transmitted disease that can cause the aforementioned abnormalities.