Resumen

Objetivo. ldentificar si existe asociación entre infección cervi­co-vaginal (ICV) y parto pretérmi­no.
Diseño. Cohortes.
Marco de referencia. Instituto Nacional de Perinatología, Hospital Central Militar y Hospital General Regio­nal No. 1, IMSS, Culiacán, Sina­loa, México.
Pacientes. 468 pa­cientes que acudieron a control prenatal y atención del parto.
In­tervenciones. Frotis en fresco, tinción de Gram y cultivo de muestras cervicovaginales obte­nidas en las siguientes etapas de la gestación: primera muestra a las 16-24 semanas de gestación, segunda muestra a las 25-32 se­manas y tercera muestra a las 33-42 semanas. Los microorga­nismos investigados fueron: Can­dida albicans, Gardnerella vagi­nalis, Ureaplasma urealyticum, Streptococcus agalactiae, Myco­plasma hominis, Neisseria go­norrhoeae, Listeria monocytoge­nes y Chlamydia trachomatis. En el caso de cultivo positivo se indi­có tratamiento específico.
Medi­ciones. Cultivo positivo o negativo para cada uno de los microor­ganismos estudiados y presencia o ausencia de parto pretérmino, en cada una de las pacientes es­tudiadas.
Resultados. De las 398 pacientes que concluyeron el estudio, 156 presentaron ICV y 242 no presentaron ICV; no hubo diferencias entre ambos grupos en la incidencia de parto pretér­mino. Los riesgos relativos signifi­cativos fueron: en la primera eta­pa, Ureaplasma urealyticum y Mycoplasma hominis con RR = 9.0 (6.81, 11.8); en la segunda etapa, Ureaplasma urealyticum con RR = 6.2 (3.30, 11.7) y Es­cherichia coli con RR = 3.4 (1.33, 8.6); en la tercera etapa Urea­plasma urealyticum con RR = 9.19 (6.93, 12.1). El análisis de regre­sión logística identificó en la se­gunda etapa a Ureaplasma urealyticum con OR = 16.6 (2.9, 93.7), estadísticamente significa­tivo p = 0.001. El análisis de su­pervivencia mostró diferencias en ambos grupos respecto a la du­ración del embarazo (p < 0.001).
Conclusiones. Existe diferencia en la duración del embarazo entre las pacientes con ICV y sin ICV. Ureaplasma urealyticum se asocia consistentemente con parto pretérmino.

Palabras clave: parto pretérmino, in­fección cervicovaginal, Ureaplasma urealyticum, factor de riesgo. 

Abstract

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.
Key words: preterm delivery, cervi­covaginal lnfectlons, Ureaplasma urealyticum, risk factor.