In women of childbearing age, bacterial vaginosis (BV) is the leading cause of abnormal vaginal discharge. An elevation in vaginal pH and foul-smelling vaginal discharge characterizes this condition¹. The prevalence of BV is relatively high world- wide, ranging from 23% to 29% in different parts of the world. In North America, when compared to other racial groupings such as whites (23%) and Asians (11%), the prevalence among women of Hispanic and Black descent was much greater, at 33% and 31% respectively (p < 0.01)².

BV is a condition that various factors can influence. Some of the factors associated with BV include age, education level, smoking, employment, marital status, alcohol consumption, douching, condom use, sexual orientation, frequency of sexual intercourse, and number of sexual partners. Women who use intrauterine devices (IUDs) are also more likely to develop BV, while hormonal contraceptives do not increase the risk of BV. Social factors such as marital status, degree of education, and smoking may also contribute to the risk of developing BV^1,3-5.

Women with BV are at a higher risk of developing sexually transmitted infections (STIs) like HIV, Chlamydia trachomatis, Trichomonas vaginalis, Mycoplasma genitalium, HPV, and HSV-2^1,6. BV can cause severe obstetric and gynecological complications. Women with BV have a higher risk of pre- mature delivery and abortion in the second trimester, with an odds ratio of 1.4 to 7.0. BV can also lead to chorioamnionitis, which is more common in BV women and can trigger the secretion of proinflammatory cytokines, potentially promoting premature delivery⁷. BV can lead to pelvic inflammatory disease (PID) after gynecological surgery, as well as endo- metritis following childbirth or an abortion. BV-associated microorganisms and their placental-crossing toxins are one of the leading causes of fetal brain injury, which can result in long-term neurological effects in children, such as hyper- activity, learning disabilities, cerebral palsy, and periventricular leukomalacia^8,9.

Prevention strategies targeting risk factors are necessary to address the significant morbidity and disability associated with BV. This study aimed to identify the prevalence and determinants of BV incidence.

1. Data collection

This was a retrospective analytical observational study with a cross-sectional approach conducted at the Sexual STI Division of the Dermatovenereology Outpatient Clinic of Dr. Soetomo Hospital in Surabaya from 2019 to 2022. Sampling was conducted using proportional and stratified random sampling techniques based on secondary data from the medical records of patients diagnosed with BV. The study used a total sampling system to determine the sample size, which meant that all new patients who met the inclusion criteria were included in the research sample, with a minimum of 53 people.

2. Statistical analysis

Data collection sheets were used to gather information for analysis. Once the data was entered, we used Microsoft Excel 2019 to organize and analyze it. The study's outcomes were presented using tables and graphs. To analyze the variables, we performed bivariate and multivariate analyses. To determine the prevalence of BV, we carried out a descriptive analysis. We used the Statistical Package for the Social Sciences (SPSS-26) to compute the chi-square value at a significance level of 5% (0.05).

1. Demographic study

From 2019 to 2022, 1465 patients visited the clinic. Out of these patients, 94 (6.42%) were diagnosed with BV. Additionally, 22 patients were diagnosed with normal fluor albus. Through exclusion and proportional and stratified random sampling techniques, 56 samples were selected for this study. Of these, 34 were BV patients, and 22 were control samples of patients with normal fluor albus. A summary of the samples is presented in Table 1.

2. Analysis of BV determinants

The univariate analysis found that only the number of sexual partners (p = 0.009) and IUD use (0.002) were significantly associated with BV. These two factors were then entered into a multivariate test using logistic regression, where it was discovered that the number of sexual partners (95% CI 1.35~26.5, p-value = 0.02) and IUD use (95% CI 1.86~ 135.02, p-value 0.01) were the determinants of BV incidence. IUD use was also the most significant determinant of BV incidence, with a smaller p-value of 0.01. A summary of the samples is presented in Table 2.

The study found that the number of sexual partners and the use of IUDs were the only factors significantly associated with the incidence of BV. Of the BV patients, 70.6% had a single partner, while 23.5% had multiple partners. The analysis revealed that there was a statistically significant correlation between the number of sexual partners and the incidence of BV (p = 0.009), which was consistent with the findings of Moreira et al. (p = 0.01) and Abdullateef et al. (p = 0.00)^12,13.

There is a significant connection between the number of sexual partners and the incidence of BV. According to a study, patients with BV who had multiple partners had a high frequency of 54.1. Another study suggested that having multiple sexual partners in the last 30 days could increase the risk of BV by 1.13 times¹⁴. These studies indicate that patients may be unaware of the high-risk sexual behavior of their partners, highlighting the importance of practicing safe sex^10,13.

According to a study by Moreira, 14 out of 20 people (70%) with BV had sexual partners who exceeded a count of two. A possible explanation for this could be that male sexual partners could be spreading the anaerobic bacteria that causes BV. As the foreskin allows the transmission of microorganisms during sexual intercourse, it appears that the frequency of BV is higher among women whose partners have not undergone circumcision, thus lending credence to this theory¹².

According to Bitew et al., there is no significant correlation between the number of sexual partners a person has over their lifetime and the incidence of BV (p = 0.103). This could be because BV is more accurately classified as a disease rather than an infection, with the frequency of sexual encounters having a greater impact on its occurrence¹¹.

A significant correlation was found (p = 0.002) between IUD use and the incidence of BV, according to an analysis in this study. In a study by Abdullateef et al., the prevalence of IUD use was reported to be 68.2% in BV patients (OR 1.61, 95%CI 0.543~4.759; p-value = 0.020). This high incidence of BV among IUD users suggests that women who are at risk of BV should consider hormonal contraception or other options before IUDs to reduce the risk of infection. The use of contraceptives at anatomical sites can cause an imbalance in vaginal flora, which can lead to BV. In contrast, estrogen increases vaginal epithelial cell glycogen content, which in turn inhibits the in vitro development of some bacteria. This may explain why hormonal contraception may lessen the risk of BV4.

Research indicates that the rate of BV was 153.6 episodes per 100 person-years (95% CI: 145.2, 162.4) in women who used IUDs. The risk of BV was 1.28-fold (95% CI: 1.12, 1.46) higher in women who used IUDs compared to those who did not use any nonhormonal contraceptives. Furthermore, the risk of BV was 1.52-fold (95% CI: 1.16, 2.00) greater in the first six months of using an IUD compared to six months before beginning, and this risk stayed elevated through 18 months of usage (p < 0.05)¹⁵.

There are two possible ways in which the use of an IUD could lead to a higher risk of BV. First, the mix of bacteria that causes BV can grow too much in the uterus and vagina if foreign objects like an IUD are present. Second, the relative abundance of two types of bacteria, Gardnerella vaginalis and Lactobacillus spp., changes during a typical menstrual cycle. Gardnerella vaginalis is more common during men- struation, while Lactobacillus spp. is less common. When an IUD is inserted, menstrual volume and duration often in- crease, which can lead to a decrease in Lactobacillus spp. If Gardnerella vaginalis growth is stimulated by the presence of blood, dysbiosis could occur during this time¹⁵.

According to this study, the incidence of BV is influenced by the number of sexual partners and the use of IUDs, with IUD use being the primary determining factor. To reduce the risk of BV, it is essential to educate potential IUD users about the possible side effects, including BV.