What happens if a yeast infection goes untreated while pregnant

Summer is here!  For those of us who are pregnant (and I am currently in my third trimester of pregnancy), the heat and humidity are just a recipe for misery.  But you know who loves heat and humidity?  Yeast.  And summertime is prime time for vaginal yeast infections.         

What is a vaginal yeast infection?

Vaginal yeast infections are caused by an overgrowth of a fungus called Candida.  All people have a balanced mix of fungus (yeast) and bacteria that naturally grow in or around the vagina.  If this natural balance is disrupted, yeast can “overgrow” and cause a yeast infection.  Other names for yeast infection are “vaginal candidiasis,” “vulvovaginal candidiasis,” or “candidal vaginitis.”

Most of the time yeast infections are random, but there are some things that can disrupt this balance and increase the chance for a vaginal yeast infection.  Yeast loves to grow in humid and wet conditions, so simple things like not changing out of a wet bathing suit or sweaty yoga pants for a long time can increase chance for a yeast infection.  Changes in hormones can also increase the chance for a yeast infection.  The change in hormones is the reason why yeast infections also happen more commonly in pregnancy. 

How do I know if I have a yeast infection?

Signs of a yeast infection may include itching, burning and redness around the opening of the vagina, pain or discomfort during urination or sexual intercourse, and white or yellow “cottage cheese like” vaginal discharge.

It is important to know, however, that signs of a yeast infection can be very similar to other vaginal infections or sexually transmitted diseases.  Because of this, if you have the above symptoms during pregnancy do not assume that it is caused by a yeast infection (even if you have had yeast infections before).  Please call and visit your OB or midwife to confirm that it is yeast and not another infection, like bacterial vaginosis or a sexually transmitted disease.  

To confirm that it is a yeast infection your healthcare provider may do a pelvic exam and take a small sample of the vaginal discharge to examine in the office or send to a laboratory before recommending treatments. 

Are yeast infections harmful?

Other than being uncomfortable and sometimes painful, yeast infections do not usually cause complications in pregnancy or for the baby during pregnancy over the background risk.  We know that every pregnancy starts out with a 3-5% chance of having a birth defect and 10-15% chance for miscarriage. This is called the background risk. 

If left untreated, however, a yeast infection could pass to your baby’s mouth during labor and delivery and may cause the baby to have a condition called “thrush”.  Baby may then return the yeast infection back to you if the baby breastfeeds (causing yeast infection on the nipples).  Very rarely a yeast infection in babies can become serious because their immune systems are not yet well-developed.

Yeast infections can also cause body-wide infections and serious complications in pregnant people, especially those who have a weakened immune system because of other health problems. 

How do I treat a yeast infection?

Good news is that yeast infections are usually easy to treat and there are treatments that can be used in pregnancy!  Yeast infections are treated either topically (by placing an antifungal medication into the vagina) or orally (by taking a pill).  

• Oral Medications:  The most common oral antifungal used to treat yeast infections is called fluconazole (Diflucan®) and is typically given once in a single 150mg dose.  It is unlikely that the use of a single low dose of oral fluconazole during pregnancy would greatly increase the chance of birth defects or complications. However, the use of high dose fluconazole for many weeks in the first trimester of pregnancy might be associated with an increase in the chance of birth defects and miscarriage.  Because of this, the Centers for Disease Control and Prevention (CDC) have posted guidelines for treating vaginal yeast infections in pregnancy and these guidelines recommend topical therapies rather than oral medication.  For more details, visit our  Fluconazole (Diflucan®) Fact Sheet.

• Topical Medications: Most common topical therapies include antifungals called azoles and are usually used over a 7-day period.  There are many types of azole medications, but the most common ones used are clotrimazole or miconazole (common trade names include Monistat®, Micatin® and Mitrazole®).  For more details, visit our  Miconazole | Clotrimazole  Fact Sheet.

Some of these topical medications are also available over-the-counter (without a prescription).  You should not use an over-the-counter yeast infection medicine without first talking to your doctor.  Like we talked about before, there are other infections that may mimic a yeast infection and you do not want to be treating the wrong infection!  If you have used an over-the-counter medication and your symptoms do not go away, see your OB or midwife.

Rarely, some individuals may have more complicated yeast infections that last for a long time or come back more than four times a year.  These may have to be treated differently.

Is there anything I can do to prevent a yeast infection?

There are some things that can be done to help lower the chance of an infection developing.  Make sure to talk to your OB or midwife about other ways to lower the chance for yeast infections.

Some of these include:

1. Change out of wet clothes (such as a swimsuit or sweaty leggings) as soon as you can.
2. Use plain warm water to clean the outside of the vaginal area. Avoid using scented tampons and menstrual pads. Avoid hygiene sprays and douching.   
3. Sleep without underwear or in loose fitting pajamas.

Unfortunately, you cannot control the pregnancy hormones, so it is not possible to completely prevent yeast infections!  But the sooner you get it treated, the sooner you can go back to enjoying the regular miseries of being pregnant during the summer!

For more information please see:

Vaginitis | ACOG

Vaginal Candidiasis | Fungal Diseases | CDC