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Fluconazole should not be used during pregnancy unless your doctor determines that it is medically necessary. There are reports of fluconazole causing birth defects when it was taken in high doses (400 mg or more for multiple days) during the first trimester of pregnancy. Evidence for the effects of lower doses of fluconazole on pregnancy is conflicting. Some studies indicate that doses higher than 150 mg may still increase the risk of heart malformations and stillbirths while others do not. However, fluconazole can be an important treatment option in some hard to treat fungal infections so its benefits may outweigh the risks in some cases. Fluconazole is safe to use while breastfeeding.

What is fluconazole?

Fluconazole is an antifungal medicine available as a generic or brand name (Diflucan).  It is one of several drugs in the class of medicines called azole antifungals. It has been in use for many years and is available only by prescription. It can be taken by mouth as a tablet or a liquid, and is also available to be given as a shot into a vein. Fluconazole is not available as a cream or suppository to apply topically. Fluconazole is excreted from your body mainly by your kidneys but also by your liver. It can interfere with the excretion of other medicines by your liver.

What is fluconazole used to treat?

Fluconazole is used to treat infections caused by a fungus in adults, children, and infants (including newborns). Fungal infections (sometimes called yeast infections) can occur in many parts of the body including the throat, esophagus, skin, vagina, breasts, urinary tract, lungs, and brain. Certain fungi exist normally in our bodies especially in the mouth, throat, and vagina. Sometimes the amount of the fungus gets out of balance resulting in symptoms of an infection. One fungus that commonly causes infection in people is Candida and a common location is the vagina.

The dose and duration of fluconazole treatment is determined by the location and severity of the fungal infection. For an uncomplicated Candida infection of the vaginal tract, a one-time dose of 150 mg taken by mouth may be prescribed. For infections at other body sites like the lungs or brain or by other fungi, fluconazole doses as high as 2000 mg per day for up to a year may be necessary.

Fluconazole is also used to prevent fungal infections in individuals with compromised immune systems such as those who recently received chemotherapy or an organ transplant.

How does fluconazole work?

Fluconazole stops fungi from growing by interfering with their ability to make a main component of their cell membrane.

If I am taking fluconazole, can it harm my baby?

Yes. There are reports of fluconazole causing various birth defects when it was taken in high doses (400 mg or more for multiple days) during the first trimester of pregnancy. Some of these birth defects affected the heart, face (short skull, cleft palate), bones, and joints. Evidence for the effects of lower doses of fluconazole on pregnancy is conflicting. Some studies indicate that low doses, even the single 150 mg dose, may still increase the risk of heart malformations and stillbirths while others do not show an increased risk.

If I am taking fluconazole and become pregnant, what should I do?

If you become pregnant while taking fluconazole, you should contact your doctor immediately. Depending on the reason you take fluconazole, your doctor may decide to discontinue it and prescribe a safer alternative if one exists.  Once you stop fluconazole, it should be out of your system in about 1 week.

If I am taking fluconazole, can I safely breastfeed my baby?

Fluconazole dose pass into breastmilk easily. However, the amount of fluconazole that a baby would get through breastmilk is less than the dose that would normally be given to a newborn so it is considered safe to use while breastfeeding. In fact, if you develop a candidial yeast infection around your nipples during breastfeeding your baby could also develop the infection in its mouth and throat. You and the baby would both be given fluconazole because the amount in your breastmilk would not be enough to treat the baby.

If I am taking fluconazole, will it be more difficult to get pregnant?

There is no information on whether fluconazole affects fertility in women or men.

If I am taking fluconazole, what should I know?

Fluconazole should not be used during pregnancy unless your doctor determines that it is medically necessary. Depending on why you are prescribed fluconazole, there may be safer treatment options. Doses of fluconazole 400 mg or more per day taken during the first trimester have been associated with birth defects in babies. The effect of lower doses is not clear.

If I am taking any medication, what should I know?

This report provides a summary of available information about the use of this medication during pregnancy. Content is from the product label unless otherwise indicated.

You may find Pregistry's expert reports about infections and the individual medications used to treat infections here,  our report about candida (yeast) infections here, and our report about vaginal fungal infections here.   Additional information can also be found in the resources below. 

For more information about fluconazole during and after pregnancy, contact http://www.womenshealth.gov/ (800-994-9662 [TDD: 888-220-5446]) or check the following links.

Pfizer: Diflucan Prescribing Information

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General information

It is very common for women to worry about having a miscarriage or giving birth to a child with a birth defect while they are pregnant. Many decisions that women make about their health during pregnancy are made with these concerns in mind.

For many women these concerns are very real. As many as 1 in 5 pregnancies end in a miscarriage, and 1 in 33 babies are born with a birth defect. These rates are considered the background population risk, which means they do not take into consideration anything about the health of the mom, the medications she is taking, or the family history of the mom or the baby’s dad. A number of different things can increase these risks, including taking certain medications during pregnancy.

It is known that most medications, including over-the-counter medications, taken during pregnancy do get passed on to the baby. Fortunately, most medicines are not harmful to the baby and can be safely taken during pregnancy. But there are some that are known to be harmful to a baby’s normal development and growth, especially when they are taken during certain times of the pregnancy. Because of this, it is important to talk with your doctor or midwife about any medications you are taking, ideally before you even try to get pregnant.

If a doctor other than the one caring for your pregnancy recommends that you start a new medicine while you are pregnant, it is important that you let them know you are pregnant.

If you do need to take a new medication while pregnant, it is important to discuss the possible risks the medicine may pose on your pregnancy with your doctor or midwife. They can help you understand the benefits and the risks of taking the medicine.

Ultimately, the decision to start, stop, or change medications during pregnancy is up to you to make, along with input from your doctor or midwife. If you do take medications during pregnancy, be sure to keep track of all the medications you are taking.