Vaginal Infections During Pregnancy: What You Need to Know

Expecting a baby is definitely an exciting and life-changing event, but let’s face it, pregnancy can also be quite uncomfortable. And the last thing you want added to the mix is a vaginal infection. 

During pregnancy, your body is going through a lot of changes that can impact your vaginal microbiome. Fluctuating hormone levels, vaginal mucus production, and lifestyle changes can all impact your vaginal flora. 

While some women may experience vaginal infections during pregnancy, there is always a chance of developing new vaginal infections. In fact, in some cases, your risk may even increase (more about that below).

Five different vaginal infections can affect pregnant people:

• Group B strep 
• Vulvovaginal candidiasis
• Bacterial vaginosis (BV)
• Urinary tract infections (UTIs)
• Aerobic vaginitis (AV)

If you have a vagina, chances are you've had to deal with an infection at some point. But have you ever wondered how pregnancy can affect your risk of vaginal problems, and what options you have for treatment? Let's dive in and explore what we know about the different types of vaginal infections during pregnancy.

Group B strep 

Streptococcus agalactiae — or Group B strep (GBS) — is a group of bacteria that lives in your gastrointestinal and genital tracts. This means that it usually colonizes without causing any particular problems. Sometimes, though, GBS will go places it isn’t supposed to and misbehave, causing serious infections. 

Around 10-30% of pregnant people are GBS-positive, but these numbers can fluctuate based on ethnicity and geographical location. In pregnant women, GBS can sometimes lead to: 

• Urinary tract infections (UTIs), 
• Postpartum and intrauterine infections
• A weakened and disrupted vaginal microbiome: abnormal vaginal pH, lower density and diversity of vaginal flora, and an increased risk of yeast infections. 

There’s also a very, very small risk that GBS will cause complications for your baby. GBS has been linked to premature birth, premature rupture of membranes (PROM), and neonatal infection. Hearing about the risks of GBS can be quite scary, but it's important to know that doctors are proactive about screening for GBS in pregnant people, usually between 36 and 37 weeks of gestation. 

If it turns out that you are GBS-positive, doctors will prescribe antibiotics during labor and delivery to prevent the infection from passing to your baby. This is called intrapartum antibiotic prophylaxis, and it's a measure taken to ensure the safety of your newborn. 

Some research has also explored probiotics as a potential alternative to antibiotic treatment. L. crispatus, L. gasseri, L. salivarius, and L. acidophilus have been proven safe and effective at limiting the growth of GBS. 

Bifidobacterium spp. and a different Streptococcus species, S. salivarius, have also been shown to stop the growth of GBS. These friendly bacteria may even be able to mitigate the risk of transmitting GBS to a fetus. 

While the data around probiotic treatment for GBS is promising, it’s still under investigation and is not yet an ACOG-recommended treatment for GBS. 

How does GBS cause disease?

GBS can avoid detection by the immune system and cause inflammation by sticking to the vaginal lining, causing symptoms.

GBS can be especially dangerous for newborns because it has a protective outer layer that's similar to human cells, making it hard for the baby's immune system to spot them and fight off an infection.

GBS interacts with other members of the vaginal microbiome

While GBS is normally considered a harmless bacteria in the vaginal microbiome of non-pregnant people — and often doesn’t cause symptoms — some research shows that it can help other pathogens to thrive.

GBS has been shown to work cooperatively with Candida albicans, one of the main culprits for yeast infections. They work together by improving each other’s ability to attach to the vaginal wall. Additionally, when both are present, they tend to dampen your immune response within the mucosal lining of your vagina. This can lead to a persisting infection as your immune system may not be able to fight it off effectively.

GBS also interacts with bacteria we typically associate with urinary tract infections (UTI) and bacterial vaginosis (BV). 

GBS and E. coli have been observed cross-feeding with one another, eating things the other can’t, which produces nutrients the other can eat. Research also shows that GBS-positive people are deficient in factors that normally inhibit the growth of E. coli, leading researchers to suspect they may cooperate to cause UTIs. 

Prevotella, which is associated with BV as well as preterm birth, is more common in GBS-positive individuals. This suggests GBS may have a role in setting the stage for other BV-associated bacteria to thrive. 

Yeast infections during pregnancy

Vulvovaginal candidiasis — aka yeast infection — is caused by an overgrowth of Candida, a fungus that naturally lives in your body. They’re super common, and 75% of women will experience a yeast infection at least once in their lifetime. 

During pregnancy, the increased estrogen levels may make you more prone to developing a yeast infection. Pregnancy can cause your immune system to decrease, your vaginal mucosa to have more glycogen, and your estrogen production to increase. Unfortunately, these are all things that Candida loves.

A yeast infection is usually nothing more than an itchy nuisance, but during pregnancy, it can cause PROM, preterm labor, and intraamniotic infection if left untreated.

Luckily, yeast infections are easily treated with antifungal vaginal creams. A small study of 78 pregnant women found that lactobacilli probiotics were useful in reducing yeast infection symptoms and limiting recurrence.

Even if you've had a yeast infection in the past, it's best to check with your doctor beforehand as some medications may not be suitable for use during pregnancy. 

UTIs and BV during pregnancy

Urinary tract infections (UTIs) and bacterial vaginosis (BV) happen when harmful bacteria overgrow in your urinary tract or vaginal microbiome, respectively. Both can lead to dysbiosis, which is when the normal vaginal flora is disrupted and the number of protective bacteria (like Lactobacilli) decreases.

Maintaining a healthy vaginal microbiome dominated by Lactobacillus is crucial during pregnancy because it helps protect both the parent and the fetus. Dysbiosis can increase the risk of preterm birth and PROM. Vaginal dysbiosis accounts for around 50% of spontaneous preterm births. 

Some studies also found that women who give birth prematurely often have lower levels of a protective Lactobacillus called L. crispatus, and higher levels of BV-associated bacteria. This can increase the risk of preterm birth, low birth weight, and chorioamnionitis, which is an infection of the placenta and amniotic fluid. Some experts and doctors are suggesting routine screening and management of BV during pregnancy check-ups to help prevent these risks.

The good news is that when UTIs and BV are diagnosed early, they're generally easy to treat with a round of antibiotics. 

While there is evidence suggesting that a diverse vaginal microbiome may increase these risks, it's important to remember that this may not be true for everyone. More research is needed to fully understand the connection between microbiomes and preterm birth. Just keep in mind that correlation doesn't always mean causation!

Aerobic vaginitis during pregnancy 

Aerobic vaginitis (AV) is a vaginal infection caused by an excess of aerobic microbes. This is different from BV, which is caused by anaerobic bacteria (meaning they don’t need oxygen to survive). Both share a similarity in that they tend to be the result of dysbiosis, and AV is often mistaken for BV. 

Some common symptoms of AV are yellow or yellow-green discharge accompanied by a foul-smelling odor, vaginal redness, and a stinging or burning sensation. 

During pregnancy, AV is associated with increased risks of premature delivery, PROM, stillbirth, as well as neonatal and maternal infections. It’s estimated that 4-8% of pregnant individuals develop AV. 

How to prevent vaginal infections during pregnancy

Since the hormonal fluctuations caused by pregnancy can make you more susceptible to vaginal infections, it’s not always possible to prevent them entirely. But, you can do a few things to look after your vaginal microbiome as much as possible.

• Track your discharge. Changes in vaginal discharge are normal during pregnancy, so ask your OB-GYN or healthcare provider what you should look out for. Abnormal-looking and foul-smelling discharge is often a telltale sign that something’s up, down there.
• Stay up to date with pregnancy check-ups. Throughout your pregnancy, your doctor will screen for infections and make sure both you and the baby are healthy. 
• Keep practicing safe sex. If you’re having sex throughout your pregnancy, keep using barrier methods like condoms and dental dams. The goal here isn’t to prevent pregnancy (it’s a bit too late for that) but rather to prevent unwanted pathogens from entering your microbiome and reduce the risk of infection. 
• Skip the feminine hygiene products. Despite the convincing marketing, washes, douches, and deodorants can disrupt your microbiome and put you at a higher risk of dysbiosis. Your vagina is self-cleaning and during pregnancy, it’s especially good at keeping out unwanted bacteria. To wash your vulva, you only need some warm water (and hypoallergenic soap at a push).
• Monitor your vaginal microbiome with Evvy An Evvy membership lets you track changes in your vaginal microbiome overtime, giving you an in depth look at the protective and disruptive microbes and providing you with a personalized care plan to shift your microbiome back into a protected state.