Online first
Research paper
Published online: 2024-04-23

open access

Page views 228
Article views/downloads 179
Get Citation

Connect on Social Media

Connect on Social Media

Effect of Ureaplasma/Mycoplasma genital tract infection on preterm labor

Marcin Przybylski1, Ilona Wicher-Gozdur1, Joanna Kippen12, Sonja Millert-Kalinska13, Agnieszka Zawiejska4, Robert Jach5, Dominik Pruski1


Objectives: 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. Material and methods: 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. Results: 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%). Conclusions: 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.

Article available in PDF format

View PDF Download PDF file


  1. Larsen B, Hwang J. Mycoplasma, Ureaplasma, and adverse pregnancy outcomes: a fresh look. Infect Dis Obstet Gynecol. 2010; 2010.
  2. Chaim W, Horowitz S, David JB, et al. Ureaplasma urealyticum in the development of postpartum endometritis. Eur J Obstet Gynecol Reprod Biol. 2003; 109(2): 145–148.
  3. Rumyantseva T, Khayrullina G, Guschin A, et al. Prevalence of Ureaplasma spp. and Mycoplasma hominis in healthy women and patients with flora alterations. Diagn Microbiol Infect Dis. 2019; 93(3): 227–231.
  4. Breugelmans M, Vancutsem E, Naessens A, et al. Association of abnormal vaginal flora and Ureaplasma species as risk factors for preterm birth: a cohort study. Acta Obstet Gynecol Scand. 2010; 89(2): 256–260.
  5. Who: Recommended Definitions, Terminology and Format for Statistical Tables Related to The Perinatal Period And Use of A New Certificate For Cause of Perinatal Deaths. Acta Obstet Gynecol Scand. 2011; 56(3): 247–253.
  6. Bałajewicz-Nowak M, Kazimierz P, Małgorzata M. [Antioxidative system in pregnant women infected by Chlamydia trachomatis, Mycoplasma hominis, Ureaplasma urealyticum]. Ginekol Pol. 2011; 82(10): 732–737.
  7. Blencowe H, Cousens S, Oestergaard MZ, et al. National, regional, and worldwide estimates of preterm birth rates in the year 2010 with time trends since 1990 for selected countries: a systematic analysis and implications. Lancet. 2012; 379(9832): 2162–2172.
  8. Jonduo ME, Vallely LM, Wand H, et al. Adverse pregnancy and birth outcomes associated with and : a systematic review and meta-analysis. BMJ Open. 2022; 12(8): e062990.
  9. Vogel I, Thorsen P, Hogan VK, et al. The joint effect of vaginal Ureaplasma urealyticum and bacterial vaginosis on adverse pregnancy outcomes. Acta Obstet Gynecol Scand. 2006; 85(7): 778–785.
  10. Harada K, Tanaka H, Komori S, et al. Vaginal infection with Ureaplasma urealyticum accounts for preterm delivery via induction of inflammatory responses. Microbiol Immunol. 2008; 52(6): 297–304.
  11. Sprong KE, Mabenge M, Wright CA, et al. species and preterm birth: current perspectives. Crit Rev Microbiol. 2020; 46(2): 169–181.
  12. Yoon BoH, Romero R, Lim JH, et al. The clinical significance of detecting Ureaplasma urealyticum by the polymerase chain reaction in the amniotic fluid of patients with preterm labor. Am J Obstet Gynecol. 2003; 189(4): 919–924.
  13. Skrzypczak J, Wirstlein PK, Wróbel M, et al. [Concentration of pro-inflammatory interleukins in cervical secretions of women with PROM and in the umbilical cord blood of their newborns]. Ginekol Pol. 2015; 86(6): 434–441.
  14. Donders GGG, Ruban K, Bellen G, et al. Mycoplasma/Ureaplasma infection in pregnancy: to screen or not to screen. J Perinat Med. 2017; 45(5): 505–515.
  15. Suzuki Yu, Horie K, Yada Y, et al. Vaginal Ureaplasma species increase chorioamnionitis in very preterm infants with preterm premature rupture of the membranes at < 28 weeks of gestation. Eur J Clin Microbiol Infect Dis. 2018; 37(12): 2371–2380.
  16. Larsson PG, Fåhraeus L, Carlsson B, et al. Premature study group of the Southeast Health Care Region of Sweden. Late miscarriage and preterm birth after treatment with clindamycin: a randomised consent design study according to Zelen. BJOG. 2006; 113(6): 629–637.
  17. Lamont RF, Duncan SLB, Mandal D, et al. Intravaginal clindamycin to reduce preterm birth in women with abnormal genital tract flora. Obstet Gynecol. 2003; 101(3): 516–522.
  18. De Francesco MA, Caracciolo S, Bonfanti C, et al. Incidence and antibiotic susceptibility of Mycoplasma hominis and Ureaplasma urealyticum isolated in Brescia, Italy, over 7 years. J Infect Chemother. 2013; 19(4): 621–627.
  19. Zhu C, Liu J, Ling Y, et al. Prevalence and antimicrobial susceptibility of Ureaplasma urealyticum and Mycoplasma hominis in Chinese women with genital infectious diseases. Indian J Dermatol Venereol Leprol. 2012; 78(3): 406–407.
  20. Redelinghuys MJ, Ehlers MM, Dreyer AW, et al. Antimicrobial susceptibility patterns of Ureaplasma species and Mycoplasma hominis in pregnant women. BMC Infect Dis. 2014; 14: 171.
  21. Ikeda M, Oshima Y, Tsumura K, et al. Antibiotic administration reduced intra-amniotic inflammation 7 days after preterm premature rupture of the membranes with intra-amniotic infection. J Matern Fetal Neonatal Med. 2023; 36(2): 2286189.
  22. Zhang Su, Xu Ke, Liu SX, et al. Retrospective Analysis of Azithromycin-Resistant and Cervical Infection Among Pregnant Women. Infect Drug Resist. 2023; 16: 3541–3549.
  23. Miyoshi Y, Suga S, Sugimi So, et al. Vaginal or and preterm delivery in women with threatened preterm labor. J Matern Fetal Neonatal Med. 2022; 35(5): 878–883.
  24. Kong F, Ma Z, James G, et al. Species identification and subtyping of Ureaplasma parvum and Ureaplasma urealyticum using PCR-based assays. J Clin Microbiol. 2000; 38(3): 1175–1179.
  25. Kawakita T, Waller J, DeYoung T, et al. Ureaplasma and Mycoplasma Screening for Pregnant Individuals Who Are at High Risk for Preterm Birth. Am J Perinatol. 2023 [Epub ahead of print].
  26. Antsaklis A, Daskalakis G, Michalas S, et al. Erythromycin treatment for subclinical Ureaplasma urealyticum infection in preterm labor. Fetal Diagn Ther. 1997; 12(2): 89–92.