Hello and thanks for your query. I shall make an effort to provide you with good professional recommendations specific to your questions. Here i am giving you information based on the researches or studies and not based on my own experience. Evidences suggests that the previous chlamydia infection may double the risk of ectopic pregnancy, in part by increasing the risk of pelvic inflammation. According to the CDC, chlamydia can increase the risk of preterm delivery. So to answer, yes previous infection can cause problem with pregnancy, but problems of previous infection are fewer than those where infection is present during pregnancy. i advice for prenatal chlamydia testing and for treatment consult the doctor. Yet again, I duly appreciate your query to me, I do hope that you have found something useful to help you and I shall be glad to answer any further apprehensions. Sincerely,