ASSOCIATION BETWEEN GENITAL TRACT COLONIZATION WITH BACTERIAL VAGINOSIS AND PRETERM LABOUR: A COMPARATIVE STUDY

Abstract

Background: Bacterial vaginosis (BV) is associated with a long and growing list of
materno-foetal complications especially preterm labour. Preterm Birth is a major
contributor to neonatal morbidity and mortality in many countries. BV is amenable to
treatment during pregnancy and treatment may present a rare opportunity to reduce
preterm birth rate and resulting risk of prematurity in the newborn.
In our environment where resources are scarce and information on the
subject is not robust, it is necessary to quantify the extent of this pathology before
advocating for screening and possibly treatment in our antenatal clinics.
Objectives: To compare the occurrence of genital tract colonization with bacterial
vaginosis and its morbidities in patients with preterm and term births; and to
determine morbidities associated with bacterial vaginosis in pregnancy
Methods: The is a prospective case control study among pregnant women managed
at the Department of Obstetrics and Gynaecology of the University of Benin
Teaching Hospital. The Case group was made up of 41 women with spontaneous
preterm labour while the controls were 41 women with spontaneous labour at term.
Upon recruitment, socio-demographic characteristics were obtained using
pretested data retrieval forms. Thereafter, a high vaginal swab for subsequent Gram
staining was obtained. Bacterial morphotypes were assessed in the swab samples
and BV was diagnosed using the 10 point Nugent score. All the women were
followed up till discharge from the hospital and other relevant information were
recorded. Association of genital tract colonization with bacterial vaginosis with preterm
labour was analyzed with the use of logistic regression while adjusting for cofounding
variables.
Results: Genital tract colonization with BV was significantly more in women with
preterm labour 17(41.5%) compared with those with spontaneous labour at term
5(12.2%) {p = 0.005, (Crude OR 5.10, 95% CI (1.66 – 15.68)}. The odds of women
with preterm labour having BV was still 5 times more than those of women with
spontaneous labour at term even after adjusting for confounding variables {p =
0.031, (Adjusted OR 5.47, 95% CI (1.16 – 25.70)}. Marital status, level of education,
social class and use of antibiotics during the study period were identified as
confounding variables in this study.
Additionally, women with BV during pregnancy had more Small for
Gestational Age babies (p = 0.001) as well as more babies admitted in the Special
Care Baby Unit (p = 0.006). Bacterial vaginosis was not associated with infectious
morbidities such as neonatal sepsis, chorioamnionitis and postpartum endometritis.
Conclusion: This study confirms BV is a risk factor for preterm labour in this
environment. This information will help in counselling women in addition to assist in
developing local guidelines about screening and treatment of bacterial vaginosis in
pregnancy.

ASSOCIATION BETWEEN GENITAL TRACT COLONIZATION WITH BACTERIAL VAGINOSIS AND PRETERM LABOUR: A COMPARATIVE STUDY