Examination of bacterial contamination at the time of embryo transfer, and its impact on the IVF/pregnancy outcome.

PURPOSE: This study was designed to examine the effect of bacterial contamination on in vitro fertilization treatment outcomes.

METHOD: In a prospective clinical trial, 152 patients aged 23-38 years, mean 33.3 +/- 4.6, undergoing IVF treatment were selected for this study. During embryo transfer, separate samples were collected for microbial examination from the following sites: the fundus of the vagina, the cervix, the embryo culture medium prior and post-embryo transfer, the tip of the catheter, and the external sheet. All the samples were separately cultured to identify any bacteria or yeast present.

RESULTS: Pregnancy rates in patients testing positive for Entrobacteriaceae (22.2% versus 51%) and Staphylococcus species (17.6% versus 44%) were significantly lower than those in the negative culture group (p < 0.001). The pregnancy rates do not seem to be affected by the other isolated microorganisms.

CONCLUSION: This study shows that the presence of vaginal-cervical microbial contamination at the time of embryo transfer is associated with significantly decreased pregnancy rates.