Prevalence and risk factors of bacterial vaginosis during pregnancy: a review

Abstract

Bacterial vaginosis (BV) is a polymicrobial disorder characterized by a decrease in Lactobacillus species and an overgrowth of facultative and anaerobic bacteria in the vaginal fluid. It is essentially an underappreciated problem, as BV has been implicated in adverse pregnancy outcomes such as preterm labour and delivery, preterm premature rupture of the membranes, low birth weight, spontaneous abortion, and postpartum infections. BV is one of the most common vaginal infections worldwide, and its prevalence is estimated to range between 10% and 30% in pregnant women according to geographic, ethnic, and care settings. Although often asymptomatic, BV may cause vaginal discharge, malodour, and discomfort. Significantly, both symptomatic and asymptomatic cases are associated with substantial maternal and neonatal complications, including preterm delivery, low birth weight, and postpartum sequelae. The prevalence of BV in pregnancy is determined by demographic features (age, race, socioeconomic status), behavioural factors (unprotected intercourse, douching), and medical history. Hormonal shifts and changes in vaginal pH during pregnancy also increase susceptibility to infection. Diagnosis is typically made using Amsel’s criteria and Nugent scoring, and treatment usually involves antibiotics, specifically metronidazole or clindamycin. However, caution should be exercised in their use due to the potential risks to the developing fetus, such as teratogenic effects and increased risk of preterm birth. Addressing persistent BV is a significant challenge, underscoring the need for proactive and responsible preventive follow-up of BV in prenatal care. Early screening, particularly in high-risk populations, is not just crucial but a proactive step towards reducing complications and ensuring the health of both mothers and newborns. Given the global burden of disease, the World Health Organization (WHO) advocates for screening and treatment of symptomatic pregnant women, with all HIV seropositive cases. However, the need for additional research to elucidate the biological pathways responsible for the association between BV and preterm birth and Low birth weight is urgent. This research is crucial to determine effective prenatal interventions that can interrupt these pathways, underscoring the importance of work in this field.