Spa composition with tea tree oil on white background

Pregnancy is a time of heightened awareness — and rightfully so. You're creating another living, breathing human, after all. One question you have may surround essential oils and whether there are any tea tree oil side effects or risks that are especially important to be mindful of while pregnant.

While there are no known risks exclusive to using tea tree oil during pregnancy, tea tree oil is poisonous if swallowed. The oil can also cause skin irritation if used incorrectly or if you're sensitive or allergic to it. Of course, if you have concerns about tea tree oil, or you just want to make sure it's safe to use during your pregnancy, ask your doctor or OB-GYN.

Tea Tree Oil Uses

Tea tree oil, which is also referred to as melaleuca oil, comes from the melaleuca plant, which is native to Australia. Manufacturers use a process called steam distillation to extract the oil from the plant and create a plant compound that's 50 to 100 times more concentrated than the plant itself, according to the Tisserand Institute.

This concentrated plant extract, more commonly known as an essential oil, has antibacterial, antifungal, antiviral, antiseptic and disinfectant properties. That's why, as a July 2014 report in the International Journal of Biosciences points out_,_ a lot of tea tree oil benefits and uses are connected to the skin and skin infections. Although research on tea tree oil is limited, the Mayo Clinic notes that it's effective for a variety of skin conditions, including:

  • Acne
  • Dandruff
  • Athlete's foot
  • Lice

Tea tree oil has also been shown to reduce congestion from a cold, improve wound healing time, protect cuts from infection, provide relief for bug bites (and it can kill bugs too), boost the immune system and improve the symptoms of the herpes-simplex 1 (or HSV-1) virus, which is responsible for cold sores.

You can buy it in its pure form or purchase products that contain the oil in its diluted form. These range from toothpaste and mouthwash to ointments and lotions to household cleaning products and laundry detergents.

Tea Tree Oil Side Effects

But, while the wide range of tea tree oil uses is impressive, you might be more concerned about its safety, especially when you're pregnant. When using tea tree oil, side effects are possible, but they're usually only mild, especially if you use the oil safely and correctly. In higher concentrations, tea tree oil can irritate the skin and cause things like:

  • Rash
  • Redness
  • Itching
  • Stinging
  • Scaling
  • Burning
  • Dryness
  • Dermatitis

Most cases are mild and develop only in a localized area — or right where you applied the tea tree oil. However, tea tree oil is poisonous if swallowed. Ingestion of the oil can cause:

Essential Oils and Pregnancy

The use of essential oils during pregnancy is a controversial subject. It hasn't been studied extensively because it's unethical to do studies that may potentially put a developing baby (and the pregnant mother) at risk. According to the National Association for Holistic Aromatherapy, one of the main concerns about using essential oils — such as tea tree oil — during pregnancy is that the active ingredients will cross the placenta and reach the baby.

This doesn't mean that it would necessarily cause any harm, but many people recommend defaulting to the precautionary principle, which states: "When an activity raises threats of harm to human health or the environment, precautionary measures should be taken even if some cause and effect relationships are not fully established scientifically." In other words, if you don't know whether something is safe, you may be better off skipping it instead of taking the chance.

The U.S. Food and Drug Administration adds that there's really no regulation on terms like "natural" and "organic" for cosmetic products like creams or lotions that contain tea tree oil. Because of this, you might not always get what you think you're getting.

The National Association for Holistic Aromatherapy takes the stance that properly diluted tea tree oil is likely safe during pregnancy, but that you should stick to the general safety guidelines for it and other pregnancy-safe essential oils. Even so, there are some oils that you're better off avoiding during your pregnancy. These oils include:

  • Aniseed
  • Basil
  • Birch
  • Camphor
  • Hyssop
  • Mugwort
  • Parsley seed or leaf
  • Pennyroyal
  • Sage
  • Tansy
  • Tarragon
  • Thuja
  • Wintergreen
  • Wormwood

Read more: Is Coconut Oil Safe to Use While You're Pregnant?

Using Tea Tree Oil Safely

So, how do you use tea tree oil safely? The first rule of thumb is never to apply undiluted essential oils, including tea tree oil, to your skin. If you're purchasing products that are already made, there's a good chance they're already diluted and formulated for topical application, but if you have the pure essential oil, you'll need to dilute it before applying it to your body.

The most common way to dilute an essential oil is by mixing it with another oil, called a "carrier oil." Examples of carrier oils include coconut oil, jojobo oil and avocado oil. Dilution ranges vary, but the Tisserand Institute recommends keeping it at a concentration between 0.2 and 20 percent, depending on what you're using it for. That means that you need only a couple of drops of tea tree oil to get the job done.

Emily Sisco, CNM, a certified nurse midwife at the Mayo Clinic Health System, recommends that pregnant women start with one drop and then increase by three to five drops, depending on how well they tolerate the oil. Sisco adds that pregnancy can increase sensitivity to smell, so exposing yourself to too much oil at once can be nauseating.

If you're using a diffuser, which is one of the most common methods of application, you'll want to alternate between periods of diffusing and periods without. Ideally, you should aim for 30 to 60 minutes of active diffusing, followed by 30 to 60 minutes without diffusing; then you can start over and continue alternating.

While these are general guidelines for keeping yourself safe, it's always a good idea to talk to your doctor before using tea tree oil, or any other essential oil, during pregnancy. If your doctor says it's safe, you can work with a registered aromatherapist to figure out the best way to get the most out of the oil, depending on what you want to use it for.