Bacterial vaginosis that lingers for months or years does more than cause discomfort. It quietly shifts the vaginal environment in ways that raise the risk of sexually transmitted infections, complicate pregnancies, and may contribute to fertility problems. BV also has a stubborn tendency to come back: roughly 58% of women experience a recurrence within 12 months of treatment, and up to 80% deal with long-term recurrence. Understanding what prolonged BV does to your body can help you take it more seriously, even when symptoms seem mild or come and go.
Why BV Keeps Coming Back
One of the defining features of chronic BV is how difficult it is to get rid of permanently. Within just one month of completing a standard course of antibiotics, about 23% of women already have BV again. By three months, that number climbs to 43%. By a year, more than half have had at least one recurrence.
The main reason is biofilm. The bacteria responsible for BV, particularly Gardnerella vaginalis, build structured communities that coat the vaginal lining. These biofilms act like a shield, blocking antibiotics from reaching the bacteria inside and helping the organisms evade your immune system. Other bacterial species in the vagina can actually promote this biofilm growth through chemical signaling, making the community more robust over time. The longer BV persists, the more established these biofilms become, which is a major reason why recurrent BV gets progressively harder to treat with each episode.
How It Changes Your Vaginal Environment
A healthy vaginal microbiome is dominated by Lactobacillus bacteria, which produce lactic acid and keep the vaginal pH below 4.5. This acidic environment is a natural defense against harmful microbes. When BV takes hold, Lactobacillus populations collapse and are replaced by a diverse mix of anaerobic bacteria. The pH rises, the protective acidity disappears, and the vaginal lining becomes inflamed.
This isn’t just a temporary shift. Long-standing BV keeps the vaginal tissue in a state of chronic, low-grade inflammation. Tissue samples from women with BV show elevated levels of multiple inflammatory signaling molecules. That ongoing inflammation weakens the mucosal barrier that normally acts as a first line of defense against infections, which is why the consequences of prolonged BV extend well beyond odor and discharge.
Higher Risk of STIs, Including HIV
The damaged mucosal barrier and disrupted microbiome make it significantly easier for sexually transmitted infections to take hold. Women with BV face roughly 60% higher risk of acquiring HIV compared to women without BV. While other individual STIs carry a higher per-exposure transmission risk, BV is so common that it may account for a comparable share of new HIV infections overall.
The increased vulnerability extends to chlamydia, gonorrhea, trichomoniasis, herpes (HSV-2), HPV, and Mycoplasma genitalium. In one clinical trial, women with asymptomatic BV who received treatment and ongoing suppressive therapy went significantly longer before acquiring a new STI compared to women who were simply observed. This suggests the BV itself, not just the behaviors associated with it, is what drives the increased susceptibility.
Pregnancy Complications
BV during pregnancy is associated with roughly double the odds of preterm delivery. It has also been linked to early miscarriage, low birth weight, infection of the uterine lining after delivery, and inflammation of the membranes surrounding the baby. These associations are well documented, though researchers still debate whether BV directly causes preterm birth or is a marker of a broader inflammatory process that triggers early labor.
For women who have had BV for a long time before becoming pregnant, the concern is that chronic disruption of the vaginal microbiome may be harder to reverse during pregnancy. If you’re planning a pregnancy and have recurring BV, addressing it beforehand gives you the best chance of restoring a Lactobacillus-dominant environment before it matters most.
Potential Impact on Fertility
One of the less discussed consequences of long-term BV involves fertility. Women with tubal infertility, where scarring or damage to the fallopian tubes prevents conception, are nearly three times more likely to have BV than women with other causes of infertility. The proposed mechanism is that BV-associated bacteria ascend from the vagina through the cervix and into the upper reproductive tract, causing silent inflammation and scarring over time.
This is particularly concerning because the damage can accumulate without obvious symptoms. You may not have pelvic pain or fever, but years of recurring or persistent BV could gradually affect the fallopian tubes. The evidence is considered circumstantial rather than definitive, but the statistical link is strong enough that researchers describe it as a plausible causal relationship.
Surgical Complications
If you need gynecological surgery while BV is active, the risks increase substantially. Women with BV face about three times the risk of vaginal cuff cellulitis (infection at the surgical site) after a hysterectomy compared to women without BV. Some studies found the risk of post-operative pelvic infection was four times higher in women with BV undergoing abdominal hysterectomy.
Post-operative fever is also more common: 36% of women with BV developed a fever after surgery, compared to 12% of women with normal vaginal flora. These risks apply to major gynecological procedures broadly, not just hysterectomy. Treating BV before scheduled surgery has been shown to significantly reduce infection rates at the surgical site, which is why screening before gynecological procedures matters.
Asymptomatic BV Carries the Same Risks
Many women with BV have no noticeable symptoms at all, no odor, no unusual discharge. This can create a false sense of security. The current understanding is that asymptomatic BV carries the same risks as symptomatic BV: the same increased susceptibility to STIs, the same pregnancy complications, the same surgical risks. Researchers have not yet established that asymptomatic BV is a milder form of the condition, and the biological disruption to the microbiome and immune environment appears similar regardless of whether you notice symptoms.
The fact that treating asymptomatic BV delayed new STI acquisition in clinical trials reinforces the idea that the absence of symptoms doesn’t mean the absence of harm. If you’ve been diagnosed with BV in the past, the infection may have returned without obvious signs.
Managing Persistent or Recurrent BV
Standard treatment for a single BV episode is a short course of antibiotics, typically lasting about a week. But for women dealing with multiple recurrences, guidelines recommend longer strategies. One approach is using a vaginal antibiotic gel twice weekly for three months or longer as suppressive therapy. This reduces recurrences while you’re using it, though the benefit tends to fade once you stop.
A more aggressive protocol involves an initial week of oral antibiotics, followed by three weeks of intravaginal boric acid, and then several months of twice-weekly vaginal antibiotic gel. This layered approach targets both the active infection and the biofilm that drives recurrence. The goal is to give Lactobacillus enough time to recolonize and reestablish the protective acidic environment, though for many women this remains an ongoing challenge rather than a one-time fix.