For pregnant women, the third trimester can bring with it a host of new and unexpected changes. One of these changes may be the appearance of cold sores. But what are cold sores?

And can you get cold sores during pregnancy third trimester? Let’s take a look at what cold sores are, what causes them during pregnancy, and how to treat them safely.

What is a Cold Sore? 

A cold sore is an infection caused by the Herpes Simplex Virus (HSV-1). They usually appear on the lips or around the mouth as small blisters that eventually burst and scab over.

These sores can be painful and can cause itching and burning sensations. While cold sores can occur at any time, they tend to flare up during times when your body is more vulnerable to stressors such as pregnancy. 

You can also check our article on Cold Sores in Throat Treatment

What are the Causes of Cold Sores During Pregnancy?

Pregnant women are particularly vulnerable to experiencing cold sores during the third trimester due to hormonal fluctuations in the body that weaken the immune system.

Additionally, physical stressors such as exhaustion and morning sickness can contribute to an increased risk of developing a cold sore during pregnancy.

Other factors that may increase your chances of getting a cold sore include kissing someone with an active cold sore or using someone else’s utensils or other personal items while they have an active outbreak. 

Signs and Symptoms of Cold Sores in Pregnancy

The most common sign of a cold sore is an area of redness around the mouth or nose that may also be sensitive to touch. Other symptoms include itching and burning sensations, as well as tingling in the area where the cold sore appears. 

In some cases, swollen lymph nodes near the infection site may also be present. These symptoms usually appear one to two days before symptoms such as blisters filled with fluid arise. The duration of these blisters usually last around 10 days before they heal up completely. 

Effects of Cold Sores on Fetal Development

Though unpleasant for pregnant women, it is important to note that getting a cold sore during pregnancy does not affect your baby’s development unless you contract HSV-2 rather than HSV-1. 

This form of the virus is transmitted through sexual contact and can cause birth defects, so if you think you have contracted either type of herpes virus, it is important to see your doctor immediately for proper diagnosis and treatment options. 

Once diagnosed with HSV-1, however, there should not be any additional concerns over its effects on fetal development as it will not spread through childbirth or breastfeedings like other illnesses such as thrush or chicken pox. So, there is no need to worry unnecessarily over this issue. 

Diagnosis of Cold Sores During Pregnancy

In order to determine if you have a cold sore, it is important that you visit your doctor right away. Your doctor will take a look at the blister on your mouth and ask you some questions about your symptoms and medical history. They may also do some laboratory tests or prescribe medication to treat any infection you may have caused by the cold sore.  

Treatment of Cold Sores while Pregnant

Once you have been diagnosed with a cold sore, there are two main treatment options available: home treatment and clinical medicine. 

1. Home Treatment

Home treatment involves using over-the-counter medications such as ointments, creams, gels, or sprays to reduce inflammation and discomfort caused by the blister(s). 

2. Clinical Medicine

Clinical medicine involves prescription medications such as antiviral medications, which can help prevent the virus from spreading further in your body and reduce the healing time for the blister(s). 

It is important that you talk to your doctor before taking any over-the-counter medications or starting prescription drugs for treating a cold sore while pregnant. 

Preventing Cold Sores During Pregnancy

The best approach to avoid developing cold sores while pregnant is to maintain proper hygiene practices, such as often washing your hands with soap & water for not less than 20 seconds each time.

Avoid touching eyes, nose, or mouth; avoiding contact with people who have active infections; get adequate rest; eat a balanced diet, and limit stress levels as much as possible. 

Additionally, stress reduction techniques such as yoga or meditation can help decrease the risk of recurrence of cold sores during pregnancy due to hormonal changes that occur throughout pregnancy stages.  

When to Worry About Cold Sores During Pregnancy?

Although most cases of cold sores during pregnancy are harmless and can be managed with over-the-counter medications or home remedies, there are certain times when you should seek medical attention right away. These include: 

• If it’s the first time you’ve ever had a cold sore – If this is your first outbreak ever, then you should seek medical attention immediately as this could indicate a more serious infection such as genital herpes, which can cause complications during delivery if left untreated. 

• If your cold sore is spreading rapidly – If your cold sore seems to be spreading quickly beyond its original site, then this could indicate something more serious than just a regular outbreak and should be addressed promptly by your doctor.  

• If you experience unusual symptoms such as fever, pain, or difficulty breathing – These symptoms could indicate that the infection has spread beyond just your mouth and face area, which requires prompt medical attention in order to prevent complications for both mother and baby during delivery.  


While getting a cold sore during pregnancy can be uncomfortable, there are ways to manage them effectively without risking harm to your baby’s health or its development in utero.

It is always best practice, however, to speak with your health care provider if you experience any unusual symptoms throughout your pregnancy just in case there may be any underlying causes requiring medical attention for both yourself and your baby’s safety.

With proper precautionary measures taken, you should have no further worries about getting cold sores during pregnancy third trimester.

We hope that this article has answered your question, “Can you get cold sores during pregnancy third trimester?”. If you have any further questions or concerns, please do not hesitate to contact your healthcare provider.