Chlamydia trachomatis is an intracellular pathogen and immunologic response to
CT infection elaborate T cell response and cytokine release. Because inflammatory reactions induce damage in tissue, preterm birth may be the consequence of those inflammatory responses [
17,
18,
25,
30,
35]. In this meta-analysis, it turned out that there is a significant relationship between
CT infections and preterm delivery. Our interpretation of the meta-regression showed that there was no significant relationship between prevalence of
CT infections and preterm delivery with the year of study (
p = 0.33) and sample size (
p = 0.21). The prevalence of
CT infections and preterm delivery in Europe and America was relatively high. Among the articles that were studied, we noted some contradictory results. In Mikhova et al. (2006) using PCR methodology found that there was no relationship between
CT infections and preterm birth observed [
26]. Another PCR study by William et al. (2000) showed that there was a connection between
CT infection and preterm birth [
18]. In a cross sectional study using culture technique, Ismail et al. (1992) reported a meaningful correlation between
Chlamydia trachomatis infections and preterm birth [
10]. In another cross sectional study by Silva et al. (1997) using bacterial cultures observed no correlation between
CT infection and preterm birth [
12]. Bogavac et al. (2001) showed that a significant relationship between the
CT infection and preterm birth was observed in a case-control study using serology [
19]. Rimbach et al. (1992) using the same method, showed no connection between preterm birth and
Chlamydia trachomatis infections [
9]. In regard to the overall results based on studies performed on diverse populations, this meta- analysis showed a clear association between preterm delivery and prior colonization with
Chlamydia trachomatis.