Bacterial Vaginosis (BV) results from an imbalance in the vagina’s natural bacterial environment, where certain bacteria outnumber beneficial lactobacilli. While it is the most frequent vaginal infection in women of childbearing age, it is not classified as a sexually transmitted infection (STI). Sexual activity can be a contributing factor because it can alter the bacterial balance within the vagina.
Factors Contributing to BV During Pregnancy
Hormonal fluctuations are a primary reason pregnant women have a heightened risk of developing bacterial vaginosis, with approximately 10% to 30% experiencing it. Elevated hormones, especially estrogen, can alter the vaginal environment, affecting its pH and creating conditions where less favorable bacteria can multiply. This hormonal influence means even those with no other risk factors can develop BV. Having a new sexual partner can also increase the likelihood by introducing different bacteria to the vaginal ecosystem.
Potential Complications for Mother and Baby
Untreated bacterial vaginosis during pregnancy can lead to health concerns for both the mother and baby. One of the most significant risks is preterm birth (delivery before 37 weeks of gestation), and there is also an increased chance of delivering a baby with a low birth weight. The connection is related to inflammation, as the bacterial overgrowth can trigger a response that may weaken the amniotic sac, leading to preterm premature rupture of membranes (PPROM). For the mother, BV can also increase the risk of a uterine lining infection, known as postpartum endometritis.
Diagnosis and Safe Treatment in Pregnancy
Diagnosing bacterial vaginosis involves a healthcare provider discussing symptoms, such as a thin, grayish-white discharge or a distinct fishy odor. To confirm the diagnosis, a provider will take a sample of vaginal fluid to examine under a microscope or to check its pH level, as BV is associated with a pH of 4.5 or higher. BV is treatable during pregnancy with antibiotics like metronidazole or clindamycin, which are safe for both mother and baby. These can be administered as oral pills or a topical gel. It is important to complete the entire course of medication, as self-treating with over-the-counter yeast infection products is not effective for BV.
Preventive Measures for Vaginal Health
To lower the risk of developing bacterial vaginosis, avoid douching, as this practice can disturb the natural balance of beneficial bacteria. When cleaning the vulva, it is best to use only warm water or a mild, unscented soap to prevent irritation. Choosing breathable, cotton underwear helps reduce moisture buildup. Always wiping from front to back after using the restroom helps prevent the transfer of bacteria from the anal region to the vagina. While research is ongoing, some evidence suggests that consuming probiotics with lactobacillus strains might help support a healthy population of protective vaginal flora.