Microbiological safety of the Dr. Arabin cervical pessary in pregnant women with short cervix

BACKGROUND: The insertion of a cervical pessary is a method for treating short cervix and preventing preterm birth. The study of the vaginal microbiota composition and the need for its routine correction after the pessary insertion remain to be investigated. To date, there are no works devoted to the assessment of changes in vaginal microbiocenosis after the cervical pessary insertion. 
AIM: The aim of this study was to assess the microbiological safety of the Dr. Arabin cervical pessary in pregnant women with short cervix. 
MATERIALS AND METHODS: This prospective study included 22 pregnant women with singleton or multiple pregnancies with short cervix (25 L.J. Salomon scale) and threatened miscarriage in the second and third trimesters who received the Dr. Arabin cervical pessary. The obtained clinical materials included the secretion of the posterolateral vaginal fornix. We used the Femoflor 16 test (NPO DNA-Technology Ltd., Moscow, Russia) as a method of molecular biological analysis. In addition, the patients independently controlled the pH of the vaginal contents using the pH-balance express test. Vaginal microbiocenosis was assessed in a dynamic manner: before the cervical pessary insertion, then every two to four weeks after it, and on the day the pessary was removed. In all 22 pregnant women, clinical material was obtained twice: before the cervical pessary was inserted and when it was removed; in 15 women (68.18%) three times, and in nine pregnant women (40.91%) four times. 
RESULTS: The analysis of vaginal microbiocenosis showed no significant changes in vaginal microbiocenosis in the examined pregnant women before and after the insertion of the cervical pessary (p 0.05). The concentration of lactobacilli remained high (in the range of 107 lg DNA copies/ml) during the entire observation period. The numbers of facultative and obligate anaerobic bacteria, as well as yeast-like fungi of the Candida genus, Ureaplasma spp., and Mycoplasma hominis were within the physiological levels. No pathogenic microorganisms such as Mycoplasma genitalium were detected in any patient. After the cervical pessary insertion against the background of normocenosis, 72.73% of pregnant women noted an increase in the amount of light and odorless discharge from their genital tract. However, we found no changes in the vaginal microbiota composition. 
CONCLUSIONS: The insertion of the Dr. Arabin cervical pessary under conditions of vaginal normocenosis is a microbiologically safe way to correct short cervix and prevent preterm birth, and does not disrupt the vaginal microflora in pregnant women before delivery.