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.

What is bacterial vaginosis?

Bacterial vaginosis is a vaginal infection caused by an imbalance of the natural bacteria found in the vagina. Normally, Lactobacillus species dominate the vaginal flora, maintaining an acidic vaginal pH that prevents the overgrowth of harmful bacteria. However, when there is a reduction in Lactobacilli and an increase in anaerobic bacteria, BV can develop.

Symptoms of bacterial vaginosis can include:

However, about half of women with bacterial vaginosis do not experience any symptoms at all. This makes it possible for BV to go undiagnosed and untreated for long periods, which is why understanding its potential impact on reproductive health is crucial.

What is infertility?

Infertility is defined as the inability to conceive after 12 months of regular, unprotected intercourse. For women over the age of 35, this timeframe is reduced to six 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.

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?

Research shows that bacterial vaginosis tends to be more common in women who are facing infertility. One study found that women facing infertility were 3.3 times more likely to have bacterial vaginosis than those who weren’t. While there seems to be a connection, researchers haven’t yet proven that it directly causes infertility.

Still, while there’s no evidence that bacterial vaginosis doesn’t directly cause infertility, research suggests it may negatively impact fertility through multiple mechanisms. 

A study from 2022 looked at how the vaginal microbiome might play a role in getting pregnant. They followed 89 women and found that about 59.6% of them were able to conceive within a year. The women who became pregnant had higher levels of Lactobacilli, while those who didn’t get pregnant showed more of a bacteria linked to bacterial vaginosis called Gardnerella.

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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 was consistent even when taking other risk factors into account.

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?

Since bacterial vaginosis is treatable with antibiotics, it’s natural to wonder whether treating it can improve fertility outcomes. While treatment can help restore a healthy vaginal microbiome, more research is needed to determine whether it directly improves fertility rates.

Some studies suggest that treating dysbiosis before assisted reproductive technologies (ART) such as IVF may lead to better outcomes. However, most research has been done on high risk populations, like those with recurrent miscarriage or recurrent implantation failure. Some research indicates that routine screening and treatment for BV before IVF may not be justified based on IVF success rates alone. 

However, recurrence rates of bacterial vaginosis are high, and restoring healthy vaginal flora may require probiotics and lifestyle changes in addition to antibiotics. If you’re trying to conceive and suspect you have BV, you can test with an Evvy Vaginal Health Test, and consult with a healthcare provider for appropriate diagnosis and treatment.

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.

FAQ

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, 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, having persistent BV can lead to ongoing discomfort, including irritation, unusual discharge, and a fishy odor, which can really 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.