Vaginal Changes During Pregnancy: What To Expect

Pregnancy is a time of incredible change for your body. From your growing belly to your shifting hormones, everything is adapting to support your baby’s growth. One area that experiences significant changes — but is often overlooked in conversations — is your vagina. From hormone changes to shifts in the vaginal microbiome, pregnancy brings about a lot of changes down there.

Knowing what to expect and what’s normal (and what isn’t) can help you feel more confident and prepared throughout your pregnancy journey. Let’s explore how pregnancy affects your vaginal health and what to look out for along the way.

Normal vaginal changes during pregnancy

Pregnancy hormones and physical changes influence your vaginal health in various ways. While these changes may feel surprising or unfamiliar, most are completely normal. Here’s what you can expect:

Increased vaginal discharge

During pregnancy, you’ll likely notice an increase in vaginal discharge, called leukorrhea. This thin, milky fluid is your body’s way of keeping the vagina clean and free from infection. As hormone levels rise, particularly estrogen, they stimulate the mucous membranes, resulting in more cervical mucus (and therefore vaginal discharge). This is entirely normal and usually harmless.

Later in pregnancy, you might notice a thick, jelly-like discharge, which is part of the mucus plug forming. The mucus plug serves as a barrier to protect your uterus from infection. As you approach labor, the plug may come out, signaling that your body is preparing for birth. If you notice a sudden gush of fluid, it could be your water breaking, and you should contact your healthcare provider.

Changes in vaginal pH

The pH level of your vagina becomes more acidic during pregnancy due to hormonal fluctuations. This shift helps prevent harmful bacteria and infections, protecting both you and your baby. While you may notice a mild odor because of this change, it’s usually not concerning unless the smell is strong or fishy, which could indicate an infection. (More on how the vaginal microbiome shifts in pregnancy below!)

Swelling

As increased blood flow supports your growing baby, your pelvic area receives more blood as well. This can make the vagina and vulva more sensitive or swollen. Although your vulva might not look swollen, it can feel swollen or more sensitive to the touch, which can vary throughout pregnancy, especially in the later months.

Your vagina and vulva might turn blue

One of the interesting — if not strange — signs of early pregnancy is your vulva and vagina turning a blue or purple hue (known as Chadwick's sign). This is caused by increased blood flow and hormonal changes, particularly the rise in estrogen levels. It's usually noticeable a few weeks into pregnancy and can help healthcare providers identify if you're pregnant during a pelvic examination. However, it's not a definite sign alone because other factors like infections or hormonal changes can also cause a similar color change.

Vulvar varicose veins

Another reason why your vulva might look blue (literally) is due to the formation of varicose veins (dark, bumpy veins). In around 8% of pregnancies, women develop varicose veins in the vaginal area due to increased blood flow and pressure. This may cause mild discomfort or a feeling of heaviness, particularly as the pregnancy goes on. Vulvar varicose veins are generally harmless and often resolve after childbirth.

Pressure and heaviness

As your baby grows, especially in the third trimester, their weight can put pressure on your pelvic floor muscles. This can create a sensation of heaviness or pressure in the vaginal area. It’s a normal part of pregnancy, but if it becomes painful or uncomfortable, talk to your healthcare provider about relief strategies.

These changes are your body’s way of protecting and preparing for childbirth, so try not to worry if you notice them — most are completely expected.

Unusual changes to watch for

While many vaginal changes are normal during pregnancy, there are some symptoms that you should discuss with your healthcare provider:

• Strong vaginal odor, vaginal itching, or a burning sensation: These could indicate an infection, such as a yeast infection or bacterial vaginosis (BV). Pregnancy can make you more susceptible to infections, so seek medical advice if you experience these symptoms.
• Abnormal discharge: Noticing more discharge is normal when you're expecting, but any drastic changes to the smell, consistency, or color of your vaginal discharge might be a sign of infection. Normal discharge in pregnancy is typically thin, clear, or milky white, and has a mild odor. Look out for clumpy, white discharge (a symptom of a yeast infection), gray discharge with a fishy smell (bacterial vaginosis), or green and frothy discharge (a potential STI).
• Bright red spotting or vaginal bleeding: Light spotting may be normal, especially early on, but it can sometimes be a sign of ectopic pregnancy. Heavy bleeding or bright red blood can be a sign of complications. It’s important to contact your healthcare provider if you experience bleeding at any stage of your pregnancy.
• Sudden gush of fluid before 37 weeks: If you notice a continuous leak or a sudden gush of fluid, this may mean your water has broken early. Seek immediate medical attention to prevent complications.‍
• Severe pain or pressure: Some very mild discomfort is normal, but severe pain or an intense sensation of heaviness could be a sign of preterm labor or pelvic issues. Don’t hesitate to reach out to your healthcare provider.

How your vaginal microbiome changes during pregnancy

Did you know your vaginal microbiome goes through its own set of changes during pregnancy? As your body adjusts, so does the environment in your vagina, thanks to shifting hormones, altered mucus production, and lifestyle changes. These factors can all impact the delicate balance of vaginal bacteria.

It’s a two-way street: your vaginal microbiome may also influence pregnancy and birth outcomes. Though research is still developing, here’s what we know so far.

First trimester

At the start of your pregnancy, your vaginal microbiome starts shifting toward a more stable population, dominated by Lactobacillus bacteria. These beneficial bacteria help protect against harmful microbes and keep your vagina healthy. For some women, this shift happens early in pregnancy; for others, it may take longer.

Research suggests that having a Lactobacillus-dominant vaginal microbiome may lower the risk of premature birth. Some studies have found that when there’s a lot of diversity (i.e., not enough Lactobacillus), there may be a higher chance of delivering early. For instance:

• In a study of mostly white and Hispanic women, those with low Lactobacillus levels tended to deliver earlier.
• Another study combining data from over 300 women found that high microbiome diversity in the first half of pregnancy was linked to higher preterm birth rates.

However, it’s important to note that these studies only show a correlation, not a cause. We don’t yet know for sure if a diverse microbiome directly leads to early delivery, but there’s a connection worth exploring.

Interestingly, research on Black women shows different patterns. In these studies, a decrease in microbiome diversity between the first and second trimesters was associated with preterm births. On the other hand, transitioning to a more diverse microbiome was linked to full-term deliveries. This highlights that the relationship between microbiome diversity and birth outcomes may vary by race.

Second trimester

By the second trimester, most pregnant women — regardless of race — tend to have a stable, low-diversity microbiome dominated by Lactobacillus. This consistency is key for maintaining a healthy pregnancy.

In addition to these microbiome changes, the cervix (the lower part of the uterus) also changes. The cervix may shorten during pregnancy, and a shorter cervix can increase the risk of preterm birth. A 2020 study found that a diverse vaginal microbiome (low in Lactobacillus) was linked to a shorter cervix, especially among younger Black women. This combination of a short cervix and high microbial diversity increased the likelihood of preterm birth.

Third trimester and the postpartum period

As you approach your due date, your vaginal microbiome usually remains stable, dominated by Lactobacillus species. Even if some women experience changes, research shows that these shifts do not necessarily predict whether they will deliver early or at full term.

Once the baby is born, the vaginal microbiome often shifts back to a more diverse state. This can last for at least a year postpartum. For some women, particularly those who get pregnant again within a short time (less than 12 months), this diverse state may increase the risk of infections due to the reduced levels of protective Lactobacillus.

If you’re curious about your vaginal microbiome's health after delivery, testing your microbiome with Evvy could help you manage any changes and keep your vagina healthy during this adjustment period.

What does this mean for you?

Right now, researchers are working to understand how the vaginal microbiome affects pregnancy outcomes, especially across different racial and ethnic groups. The studies so far show that the diversity and stability of the microbiome could play a role in predicting birth outcomes, but we still need more research to confirm these findings.

If you’re pregnant and interested in understanding how your microbiome is changing, monitoring it with Evvy might give you helpful insights. Testing throughout your pregnancy could help identify any changes that might need attention.

Race, pregnancy, and the vaginal microbiome

There are clear racial differences in vaginal health outcomes — but researchers aren’t sure why. For example, Black women are three times more likely to die from pregnancy-related causes than white women. Research shows that women of African ancestry often experience more significant shifts in their vaginal microbiome, especially during the first trimester, and that the type of Lactobacillus dominant in their microbiome may vary compared to other groups.

These findings highlight the need for more diverse studies to understand how race and ethnicity influence the microbiome and pregnancy outcomes better. Continued research on diverse populations is key to developing more effective ways to support the health of all pregnant women.

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