In every pregnancy, a woman starts out with a 3-5% chance of having a baby with a birth defect. This is called her background risk. This sheet talks about whether exposure to fluconazole may increase the risk for birth defects over that background risk. This information should not take the place of medical care and advice from your health care provider.

What is fluconazole?

Fluconazole is a medicine that is used to treat fungal infections. It is most commonly taken by mouth. It is used in the treatment of vaginal yeast infections when topical creams are not effective. A single dose of 150 mg is the most commonly used dose to treat vaginal yeast infections. It is also used for fungal infections that have spread throughout the body and daily doses up to 800 mg daily may be used for this condition. Fluconazole is sold in the United States under the name Diflucan®.

I would like to stop taking fluconazole before I get pregnant. How long does fluconazole stay in the body?

Individuals break down medication at different rates. On average, it takes 6 to 9 days for fluconazole to leave your body. It is always recommended that you talk to your health care provider and discuss what treatments are best for you when planning a pregnancy.

Can taking fluconazole during early pregnancy increase the chance of miscarriage?

Studies looking at the use of low doses of fluconazole did not find a higher chance of miscarriage in two studies that involved over 500 women who used fluconazole in the months before or during their pregnancy. A third study looked at miscarriages among women who filled a prescription for single-dose oral fluconazole for vaginal yeast infection between weeks 7 and 22 weeks of their pregnancy. They found a slightly higher chance of miscarriage than expected. This type of study cannot tell if these women actually used the medication after filling their prescription, and has other flaws; making it hard to confirm that the chance for pregnancy loss was really higher in this group. Because miscarriage is common, additional studies will be needed to help determine if fluconazole plays a role in causing miscarriage or not. The FDA is looking at the research and recommends not using this medication for yeast infection until they complete their review of the research. The Centers for Disease Control (CDC) recommends the use of topical medications for yeast infection.

Can taking fluconazole during the first trimester of pregnancy cause birth defects?

It may depend on the dose and the length of time the medication is used during pregnancy. Studies looking at the use of low doses of fluconazole (mostly a single dose of 150 mg) in more than 1,600 women during the first trimester of pregnancy did not show an increased chance of birth defects. Another study with 7,000 women who used low doses of fluconazole (150 to 300 mg) did not show an increased chance for birth defects after first trimester use. The information on higher dose exposure is unclear. A pattern of birth defects of the head, face, bones and heart were reported in the five children of four mothers that took high doses (400 to 1200 mg per day) of fluconazole for many weeks to treat severe fungal infections. These cases on their own cannot prove cause and effect, but the unusual infant findings have raised concern that the high dose of fluconazole may be the cause of the birth defects.

In summary, it is unlikely that the use of a single low dose of fluconazole during early pregnancy would greatly increase the chance of birth defects. However, the use of high dose fluconazole for many weeks might be associated with a small increase of birth defects.

Can taking fluconazole cause other pregnancy problems?

Studies have not found an increase in premature birth (born before 37 weeks) or low birth weight following a single dose of fluconazole. More data is needed to confirm these findings. There are no studies for high dose/long-term treatment.

I think I have a vaginal yeast infection and I am pregnant. Should I try an over-the-counter antifungal cream instead?

If you think you have a vaginal yeast infection during pregnancy, it’s important to see your health care provider to be sure of the diagnosis. If you have another kind of vaginal infection, it may be important to treat it differently.

Can I take fluconazole for a vaginal infection while breastfeeding?

Most likely. While it hasn’t been well studied during breastfeeding, fluconazole is commonly prescribed during this time. Fluconazole can enter breast milk, but the dose to the breastfed infant would be much less than the dose used to treat an infant with an infection. The treatment of a vaginal infection often requires only a single dose of fluconazole and is unlikely to pose a risk to the breastfed infant. Talk with your healthcare provider about all of your breastfeeding questions.

Can I take fluconazole for a yeast infection in my breast while breastfeeding?

The treatment of choice for a yeast infection of the breast is a topical antifungal. If the topical treatment is not effective, oral fluconazole is usually considered. The minimum time to take this treatment is usually two weeks. Breastfeeding can be continued in this situation.

If you have a yeast infection in your breast, your infant may or may not have oral thrush (a yeast infection in the mouth). In both cases, your infant will have to be treated properly while you take fluconazole, because the amount of fluconazole transferred through breast milk is not enough to treat the infant.

Talk with your healthcare provider about all of your breastfeeding questions.

What if the father of the baby takes fluconazole?

There is no evidence to suggest that a father’s use of fluconazole causes infertility or birth defects. In general, exposures that fathers have are unlikely to increase risks to a pregnancy. For more information, please see the MotherToBaby fact sheet on Paternal Exposures and Pregnancy at https://mothertobaby.wpengine.com/fact-sheets/paternal-exposures-pregnancy/pdf/.

References available upon request.