Effect of Ureaplasma/Mycoplasma genital tract infection on preterm labor

Genitourinary tract infections in pregnant women are one of the causes of abnormal pregnancy development including miscarriages, premature labor or premature rupture of membranes (PPROM). Atypical bacteria responsible for reproductive tract infections include Mycoplasma genitalium, Mycoplasma hominis, Ureaplasma urealyticum and Ureaplasma parvum. Identification of pathogens and appropriately selected therapy can improve obstetric outcomes in patients with symptoms of threatened miscarriage or threatened preterm labor. The purpose of our study is to analyze the impact of reproductive tract infections with ureaplasma and mycoplasma bacteria during pregnancy.

In the presented study, we retrospectively analyzed the cases of 201 pregnant patients hospitalized in the Obstetrics and Gynecology Department of Poznan Regional Hospital in 2019-2022, who had a swab taken from external os area of the cervix for atypical bacteria - Ureaplasma and Mycoplasma. Only patients with symptoms of threatened miscarriage or threatened preterm labor were included in the study group. Microbiological tests were performed in the hospital laboratory with the Mycoplasma IST 3 test from Biomerieux.

We found a higher incidence of preterm labor in patients with symptoms of threatened preterm labor and a genital tract infection with Ureaplasma/Mycoplasma bacteria, compared to patients not infected with Mycoplasma/Ureaplasma - 31.1% vs 20% (p = 0.098). This observation in the case of Ureaplasma/Mycoplasma monoinfection group applied to 6 patients. - 75% of the group. Pregnant patients who had co-infection with other types of bacteria (48 patients in total) gave birth before 37 weeks of pregnancy in 27.1% of cases. We obtained a significant difference (p = 0.007) when comparing groups with positive and negative cultures for Ureaplasma/Mycoplasma by the presence of monoinfection/coinfection and the week of pregnancy in which delivery occurred. We also noted the effect of atypical bacterial infection for PPROM - this complication preceded preterm delivery in 40% of ureaplasma-positive patients, compared to 20% of PPROM without infection. We found a similar rate of preterm labor and pregnancy loss in Ureaplasma/Mycoplasma-positive patients who received antibiotic therapy (35.7%) compared to a group of pregnant women who did not receive treatment (31.6%).

Infection of the genital tract with atypical bacteria Ureaplasma and Mycoplasma has a negative impact on the course of pregnancy. Identification of the type of microorganisms in cervical canal secretions of pregnant patients with symptoms of threatened miscarriage or preterm labor seems crucial. The impact of antibiotic therapy though, requires further analysis.