Does cervical infection affect the results of IVF and ICSI? a meta-analysis of controlled studies

Abstract

Objective: Cervical infection has been claimed by some clinicians to diminish the pregnancy and implantation rates in IVF and ICSI. However, some studies have found no relationship between cervical infection and the pregnancy and implantation rate. The aim of this work was to conduct a meta-analysis of controlled trials in order to clarify the situation. We have calculated that in order to improve the clinical pregnancy rate from 25 to 30%, the least number needed to study was 636 patients in each arm of the study, accepting a probability of 80% of detecting a true difference and taking 5% as the level of significance.Design: A meta-analysis of controlled studies on the relation between cervical infection and the results of IVF and ICSI.Materials and Methods: A meticulous search of the literature was conducted searching the Medline database, the EMBase, the Cochrane library as well as hand searching relevant publications and proceedings of international congresses. A total of 71 studies were retrieved. The studies were evaluated independently by the first two reviewers and the differences were settled by consensus with the third reviewer. Of the 71 studies, 4 fulfilled our inclusion criteria (Egbase et al, 1996; Fanchin et al, 1998; Moore et al, 2000; Salim et al, 2002). The primary outcome measures were the clinical pregnancy and implantation rates. The meta-analysis was conducted using the RevMan software with the Peto-modified Mantel-Haenszel method and the fixed effect model.Results: The clinical pregnancy rate for patients with cervical infection (positive cultures) was 21.0% compared to 38.4% for patients with no infection (negative cultures) [OR = 0.42 (95% CI 0.29–0.60)]. The implantation rate for patients with cervical infection was 7.6% compared to 16.4% for those with no infection [OR = 0.43 (95% CI 0.31 – 0.61)].Conclusion: Cervical infection during embryo transfer diminishes the pregnancy and implantation rates significantly for patients undergoing IVF and ICSI. Objective: Cervical infection has been claimed by some clinicians to diminish the pregnancy and implantation rates in IVF and ICSI. However, some studies have found no relationship between cervical infection and the pregnancy and implantation rate. The aim of this work was to conduct a meta-analysis of controlled trials in order to clarify the situation. We have calculated that in order to improve the clinical pregnancy rate from 25 to 30%, the least number needed to study was 636 patients in each arm of the study, accepting a probability of 80% of detecting a true difference and taking 5% as the level of significance. Design: A meta-analysis of controlled studies on the relation between cervical infection and the results of IVF and ICSI. Materials and Methods: A meticulous search of the literature was conducted searching the Medline database, the EMBase, the Cochrane library as well as hand searching relevant publications and proceedings of international congresses. A total of 71 studies were retrieved. The studies were evaluated independently by the first two reviewers and the differences were settled by consensus with the third reviewer. Of the 71 studies, 4 fulfilled our inclusion criteria (Egbase et al, 1996; Fanchin et al, 1998; Moore et al, 2000; Salim et al, 2002). The primary outcome measures were the clinical pregnancy and implantation rates. The meta-analysis was conducted using the RevMan software with the Peto-modified Mantel-Haenszel method and the fixed effect model. Results: The clinical pregnancy rate for patients with cervical infection (positive cultures) was 21.0% compared to 38.4% for patients with no infection (negative cultures) [OR = 0.42 (95% CI 0.29–0.60)]. The implantation rate for patients with cervical infection was 7.6% compared to 16.4% for those with no infection [OR = 0.43 (95% CI 0.31 – 0.61)]. Conclusion: Cervical infection during embryo transfer diminishes the pregnancy and implantation rates significantly for patients undergoing IVF and ICSI.