RESUMEN
INTRODUCTION: This study aimed to determine the incidence of lower genital infections and related factors in preterm premature rupture of membranes (PPROM) and preterm labor. METHODOLOGY: A case-control study was conducted on pregnant women who were admitted to the Hospital of Hue University of Medicine and Pharmacy, Vietnam between November 2017 and May 2019. Cases from 22 to 36 gestational weeks were included as group 1 (patients with preterm labor and intact membranes) or as group 2 (those with PPROM). The control group included women with singleton pregnancies who were matched on gestational age and recruited concurrently with the study cases. Gram stain was perfomed to identify Lactobacillus, Gardnerella, mobiluncus, Candida, and leucocytes. Trichomonas vaginalis was detected by wet mount. Cultures of vaginal secretions and aminotic fluid were performed to identify aerobic bacteria. RESULTS: Bacterial vaginosis was higher in group 1 (28.9%) compared to control (11.4%). The incidence of isolated aerobic bacteria was 44.1% in group 2, 11.1% in group 1, and 12.7% in the control group (p < 0.001). Fungal infection was not shown to be a risk factor for preterm labor (p = 0.990), whereas, bacterial vaginosis was (OR = 3.16; 95%CI = 1.23-8.15; p = 0.016). Isolated aerobic bacteria were associated with premature rupture of membranes (OR = 5.45; 95%CI = 2.11-14.05; p < 0.001). CONCLUSIONS: Bacteria vaginosis increased the risk of preterm labor and preterm premature rupture of membranes. Isolated aerobic bacteria were related to PPROM, while fungal infection was not associated with preterm labor.