Can BV Cause Infertility or Prevent Pregnancy?

Bacterial vaginosis (BV) is a common vaginal infection that affects millions of women worldwide. While it is often associated with unpleasant symptoms such as abnormal discharge and a fishy odor, some women may not experience any symptoms at all. 

One of the biggest concerns surrounding bacterial vaginosis is its potential impact on fertility. Can BV make it harder for women to conceive? Below, we’ll explore what BV is and whether it's linked to difficulties in getting pregnant.

Key takeaways 

• While BV doesn't directly cause infertility, research links it to fertility challenges — women with infertility are 3.3 times more likely to have BV than those without.
• Two main mechanisms are involved: BV raises the risk of pelvic inflammatory disease (PID), which can scar or block fallopian tubes, and it triggers inflammation that makes the vaginal environment less favorable for sperm.
• BV is also linked to higher miscarriage risk and poorer IVF outcomes.
• If you're trying to conceive, test with the Evvy Vaginal Microbiome Test and consult a healthcare provider.

What is bacterial vaginosis?

Bacterial vaginosis is a vaginal infection caused by an imbalance of natural bacteria in the vagina. Normally, Lactobacillus species dominate the vaginal flora, maintaining an acidic vaginal pH that prevents harmful bacteria from overgrowing. When Lactobacilli decrease, and anaerobic bacteria increase, BV can develop. Symptoms can include:

• Thin, grayish-white vaginal discharge
• A strong, fishy odor, especially after sex
• Vaginal itching or irritation
• Burning when you pee. 

About half of women with BV have no symptoms at all, which is why it can go undiagnosed for long periods, making its impact on reproductive health worth understanding.

What is infertility?

Infertility is defined as the inability to conceive after 12 months of regular, unprotected intercourse. For women over 35, this timeframe is reduced to 6 months due to the natural decline in fertility with age. Infertility can result from issues in either the male or female reproductive system or a combination of both.

Other common causes of female infertility

Several factors can contribute to female infertility, including:

• Ovulatory disorders: Ovulation problems are one of the leading causes of female infertility. Conditions like polycystic ovary syndrome (PCOS) and primary ovarian insufficiency (POI) can disrupt regular ovulation, making conception difficult. PCOS is responsible for up to 80% of ovulatory infertility cases.
• Endometriosis: Endometriosis occurs when tissue similar to the lining of the uterus grows outside the uterus, causing pain, inflammation, and potential scarring. This condition can interfere with implantation and damage the fallopian tubes, leading to infertility. One study found that 30-50% of women with endometriosis experience infertility.
• Tubal factor infertility: Blocked or damaged fallopian tubes prevent the sperm from reaching the egg or hinder the fertilized egg from traveling to the uterus. This can result from pelvic inflammatory disease (PID), previous infections, or surgery. Bacterial vaginosis is considered a potential risk factor for PID, which may contribute to tubal infertility.
• Uterine abnormalities: Fibroids, polyps, and congenital abnormalities of the uterus can affect implantation and increase the risk of miscarriage.
• Hormonal Imbalances: Hormones play a critical role in regulating ovulation, egg quality, and the overall menstrual cycle. Conditions like thyroid disorders and hyperprolactinemia can disrupt reproductive function.
• Unexplained infertility: In some cases, infertility remains unexplained despite thorough testing. This means that no identifiable cause can be found, even after evaluating ovulation, fallopian tube function, and sperm quality. Unexplained infertility accounts for approximately 15-30% of infertility cases. 

Can BV cause infertility?

BV hasn't been proven to cause infertility directly, but it's strongly linked to it. Researchers believe it may affect fertility through several mechanisms, including inflammation and increased PID risk.

Research shows that bacterial vaginosis is more common in women facing infertility. One study found women with infertility were 3.3 times more likely to have BV than those without. The connection is clear, but a direct causal link hasn't been proven yet.

Still, research suggests BV may negatively affect fertility through multiple mechanisms. A 2022 study following 89 women trying to conceive found that 59.6% became pregnant within a year. Those who conceived had higher levels of Lactobacillus, while those who didn't had higher levels of Gardnerella, a bacterium linked to BV.

Bacterial vaginosis and pelvic inflammatory disease

BV is associated with an increased risk of PID, a serious infection that affects the upper genital tract (uterus, fallopian tubes, and ovaries). PID can lead to scarring and blockages in the fallopian tubes, a major cause of infertility. 

Bacterial vaginosis and inflammation

An imbalance of vaginal bacteria (dysbiosis) can trigger an inflammatory response. This inflammation causes the release of cytokines and other substances that promote inflammation. Unfortunately, this can harm the vaginal and cervical tissues, making it a less favorable environment for sperm, reducing their ability to reach and fertilize an egg. 

Bacterial vaginosis and assisted reproductive technology 

For women undergoing assisted reproductive technology (ART), such as in vitro fertilization (IVF), BV may lower the chances of successful implantation. 

Research found that most patients receiving ART have an abnormal vaginal flora, while women with Lactobacillus-dominated vaginal microbiomes have higher pregnancy rates. A meta-analysis of 17 studies found that vaginal dysbiosis was associated with poorer IVF outcomes. Additionally, vaginal microbiomes dominated by L. crispatus have been linked with higher rates of embryo implantation and live births after IVF.

Bacterial vaginosis and miscarriage risk

Research has shown that women who have bacterial vaginosis may experience a significant increase in the risk of miscarriage in the first trimester. A study involving women going through IVF found that those with BV had a miscarriage rate of 31.6%, compared to 18.5% for those with healthy vaginal flora. This trend remained consistent even after accounting for other risk factors.

Interestingly, first-trimester miscarriages seem to coincide with a decrease in beneficial Lactobacillus bacteria and an increase in the variety of other bacterial communities. A meta-analysis of 25 studies found that vaginal dysbiosis (either BV or AV) was correlated with higher early pregnancy loss. 

It’s important to remember that while BV is associated with a higher risk of miscarriage, not every woman with BV will face pregnancy loss. The research does indicate that BV is a notable risk factor, especially in early pregnancy. However, the connection between BV and first-trimester miscarriage still needs more exploration.

If you’re worried about bacterial vaginosis and how it might affect your pregnancy, it’s a great idea to chat with your healthcare provider. They can offer personalized advice and the right treatment if needed.

Can treating bacterial vaginosis improve fertility?

While treatment can help restore a healthy vaginal microbiome, more research is needed to determine whether it directly improves fertility rates. Some studies suggest treating dysbiosis before assisted reproductive technologies (ART) like IVF may lead to better outcomes, though most research has focused on high-risk populations, such as those with recurrent miscarriage or implantation failure. Some evidence suggests routine BV screening before IVF may not be justified by success rates alone.

Still, an imbalanced vaginal microbiome has been linked not only to BV but also to infertility, recurrent pregnancy loss, and pregnancy complications, while a healthy microbiome is associated with better fertility outcomes, including implantation success.

If you're actively trying to conceive, it’s generally recommended to treat BV first. Standard treatments like metronidazole and clindamycin are considered safe to use while trying to conceive, and metronidazole is also generally considered safe if you're already pregnant — though your provider should confirm this based on your specific situation. After treatment, it's worth retesting to confirm the infection has fully cleared before trying again, since treating with active BV may carry added risk.

If BV keeps coming back, it's worth addressing recurrence before conception rather than during early pregnancy, when treatment options are more limited. Loop in your OB-GYN or fertility provider if you have recurrent BV, are undergoing fertility treatment like IVF, or have a history of pregnancy loss. They can help you weigh testing and treatment options as part of your broader conception plan.

How to maintain a healthy vaginal microbiome

While BV can’t always be prevented, certain lifestyle habits may help support a healthy microbiome:

• Avoid douching, which disrupts the natural balance of bacteria.
• Practice safe sex by using condoms to reduce the risk of infections.
• Take probiotics, particularly those containing Lactobacillus strains.
• Maintain good hygiene, but avoid overly harsh soaps or scented products.

FAQs about BV and fertility

Can BV stop you from getting pregnant?

While it doesn't directly prevent pregnancy, BV has been linked to some fertility challenges. Bacterial vaginosis can put you at an increased risk of pelvic inflammatory disease (PID), which can lead to scarring or blockages in the fallopian tubes, making it harder to conceive. Furthermore, BV can cause some inflammation and changes in the vaginal environment that may not be ideal for sperm, potentially lowering the chances of fertilization. There are even some studies suggesting that BV might affect the success rates of in vitro fertilization. If you're trying to conceive, it's a great idea to talk to a healthcare provider. They can help you manage the condition and keep things on track for your fertility journey.

What happens if BV goes untreated?

Untreated BV increases the chances of developing PID, which can cause some complications like scarring in the fallopian tubes and may even result in infertility down the line. Also, untreated BV can make you more susceptible to sexually transmitted infections (STIs) like chlamydia and gonorrhea, as it creates an environment where harmful bacteria can easily flourish. For pregnant women, bacterial vaginosis can increase the risk of complications such as preterm birth, low birth weight, and even miscarriage. On top of that, persistent BV can cause ongoing discomfort, including irritation, abnormal discharge, and a fishy odor, which can significantly affect your overall well-being and quality of life.

Can BV cause blocked fallopian tubes?

BV itself doesn’t directly cause blocked fallopian tubes, but it can raise the risk of pelvic inflammatory disease, which is a common cause of tubal blockage. If BV isn’t treated, harmful bacteria can travel from the vagina to the uterus and fallopian tubes, leading to inflammation and infection. Over time, this might create scar tissue that can block the fallopian tubes, making it harder for sperm to reach the egg and affecting your chances of conception. While not everyone with BV will experience PID or infertility, repeated or untreated infections can lead to long-term reproductive health concerns. The good news is that getting prompt treatment for BV can really help lower the risk of complications that might affect your fertility.

Can you get pregnant after BV treatment?

Yes. BV treatment doesn't affect your ability to get pregnant, and many people conceive without issue after clearing it up. It's a good idea to confirm that the infection has fully resolved with a retest before trying again, just to make sure you're starting from a healthy baseline.

Can untreated BV cause infertility?

Untreated BV hasn't been proven to cause infertility directly, but it raises the risk of pelvic inflammatory disease, which can scar or block the fallopian tubes (a known cause of infertility). The longer BV goes untreated, the more chances it has to contribute to these complications, so it's best not to leave it unaddressed.

How do you prevent BV while trying to get pregnant?

There's no way to fully prevent BV, but a few habits can significantly lower your risk. Avoid douching, since it disrupts your natural bacterial balance, quit smoking, and consider taking a probiotic with Lactobacillus strains to support a healthy vaginal microbiome. Under normal circumstances, condoms are one of the most effective ways to reduce BV risk, but that's not really an option when you're trying to conceive. BV can be passed between partners, and emerging research has found that treating male partners alongside female partners can significantly reduce BV recurrence. If you're dealing with recurrent BV while TTC, it may be worth asking your provider whether partner treatment makes sense for your situation, alongside your own treatment plan.

How long does it take for BV to cause infertility?

There's no set timeline, since BV doesn't directly cause infertility for most people. The risk comes from complications like PID, which can develop with repeated or prolonged untreated infections. The longer BV is left untreated, the greater the chance of these complications building up over time.

Can you get pregnant with BV?

Yes, you can get pregnant while you have BV. It doesn't typically prevent conception outright, though it's linked to a higher risk of complications like miscarriage, so it's worth getting tested and treated, especially if you're actively trying to conceive.

Can sperm survive if you have BV?

Yes, sperm can survive if you have BV, but the altered vaginal environment makes it harder. A healthy vagina is naturally acidic, which protects against infection, and semen temporarily buffers this acidity to help sperm survive. BV disrupts that balance, causing pH shifts that can impair sperm motility and viability. Bacterial overgrowth also produces toxins that can directly impair sperm function, making it harder for sperm to fertilize an egg.