Objective: To identify the possible association between cervicovaginal infections (CVI) and preterm delivery.
Design: Cohorts. REFERENCE FRAME: Instituto Nacional de Perinatología, Hospital Central Militar and Hospital General Regional No. 1, IMSS, Culiacán, Sinaloa, México.
Patients: Four hundred and sixty eight patients attending prenatal control and delivery care.
Interventions: Fresh smears, Gram stain, and cervicovaginal sample culture from samples obtained during the following gestational stages: First sample at 16-24 weeks, second sample at 25-32 weeks, and third sample at 33-42 weeks. The following microorganisms were studied: Candida albicans, Gardnerella vaginalis, Ureaplasma urealyticum, Streptococcus agalactiae, Mycoplasma hominis, Neisseria gonorrhoeae, Listeria monocytogenes, and Chlamydia trachomatis. In case of a positive culture, the specific treatment was indicated.
Measurements: Positive or negative culture for each of the studied pathogens, and the presence or absence of a preterm delivery for each of the patients included in the study.
Results: Three hundred and ninety eight were still present at the end of the study, of which 156 had a CVI and 242 had no CVI. No differences between both groups were observed concerning preterm delivery. Significant relative risks were: In the first stage, Ureaplasma urealyticum and Mycoplasma hominis with RR = 9.0 (6.81, 11.8); in the second stage, Ureaplasma urealyticum with RR = 6.2 (3.30, 11.7) and Escherichia coli with RR = 3.4 (1.33, 8.6); in the third stage, Ureaplasma urealyticum with RR = 9.19 (6.93, 12.1). The logistic regression analysis identified Ureaplasma urealyticum during the second stage with OR = 16.6 (2.9, 93.7), statistically significant with p = 0.001. The survival analysis showed differences between the two groups concerning pregnancy duration (p < 0.001).
Conclusions: There is a difference in the duration in pregnancy in patients with CVI and without CVI. Ureaplasma urealyticum is consistently associated with preterm delivery.