Essential Oils in Pregnancy: What's Safe, What to Avoid, and How to Make the Most of Them

Pregnancy is a time when your senses are heightened, your body is working overtime and small comforts matter more than ever. It's no wonder so many expectant mothers turn to aromatherapy.  The gentle scent of lavender on a pillow, the calming ritual of a warm bath with a few drops of chamomile. But alongside the glow comes a question: is this actually safe?

The short answer is: some oils are, some aren't and the trimester matters. Here's everything you need to know.

Why Pregnancy Changes the Rules

Essential oils are powerful. They aren't just pleasant smells, they're highly concentrated plant compounds that can be absorbed through the skin and inhaled into the bloodstream. Under normal circumstances, that's part of their appeal. During pregnancy, however, certain compounds can cross the placental barrier, stimulate uterine contractions, or interfere with hormonal balance.

Your liver also processes things differently when you're pregnant, meaning compounds that your body would ordinarily metabolise quickly may linger longer. This doesn't mean aromatherapy is off-limits though, it means it deserves a little more thought.

The Safest Approach: The Trimester Rule

First Trimester (Weeks 1–12): Id avoid

The first trimester is the period of highest risk. Your baby's organs are forming, and the pregnancy itself is at its most fragile.  Id almost always recommend avoiding essential oils during the 1st trimester.

Second and Third Trimesters: Still with Caution

From around 13–14 weeks onwards, most safe essential oils can be used with greater confidence, though correct dilution and sensible use remain important. A carrier oil dilution of 1% (roughly 2 drops of essential oil per teaspoon of carrier oil) is the standard recommendation for pregnancy, compared to the usual 2–3% blends.

Oils Generally Considered Safe in Pregnancy

These oils have a long history of use during pregnancy and are widely regarded as low-risk when used appropriately from the second trimester onwards:

Lavender (Lavandula angustifolia)  The best for relaxation. Excellent for anxiety, sleep difficulties, and mild headaches. One of the most studied and widely trusted oils for pregnancy.

Chamomile (Roman, Anthemis nobilis)  Soothing and anti-inflammatory. Good for irritability, tension, and digestive discomfort. Use in small amounts.

Frankincense (Boswellia carterii)  Grounding and calming, often used in breathwork. Helpful for anxiety and centring the mind.  My favourite!

Ylang Ylang (Cananga odorata) Floral and uplifting. Sometimes used to ease low mood and tension. Use sparingly as in high concentrations it can cause headaches.

Neroli (Citrus aurantium var. amara) A beautiful, delicate oil associated with easing anxiety and emotional upheaval. Often recommended in later pregnancy to prepare emotionally for birth.

Mandarin (Citrus reticulata) Gently uplifting and safe even in earlier pregnancy according to many practitioners. Lovely for nausea and general low mood.

Sweet Orange (Citrus sinensis)  Cheerful, warming, and widely regarded as safe. A good choice for a diffuser blend.

Bergamot (Citrus bergamia, FCF) The bergapten-free (FCF) version is safe for use during pregnancy. Uplifting and useful for anxiety. Avoid on skin before sun exposure.

Oils to Avoid During Pregnancy

The following oils are commonly cited as unsafe during pregnancy due to their potential to stimulate uterine contractions, disrupt hormones, or cause other complications:

• Clary Sage Can stimulate contractions. Sometimes used during labour under midwife guidance, but not before.

• Rosemary Stimulating and potentially hypertensive. Avoid throughout pregnancy.

• Sage Contains thujone, which is toxic in larger amounts.

• Thyme Strong phenol content; best avoided.

• Oregano Too stimulating; avoid entirely.

• Cinnamon Bark Irritating and potentially uterine-stimulating.

• Basil (estragole chemotype) Potentially mutagenic; avoid.

• Pennyroyal Historically used as an abortifacient. Never use during pregnancy.

• Wormwood, Tansy, Rue Highly toxic; avoid completely.

• Wintergreen and Birch Contain methyl salicylate, similar to aspirin.

• Camphor Can cross the placental barrier and cause harm.

This isn't an exhaustive list. When in doubt about a specific oil, always consult a qualified aromatherapist or a midwife qualified to advise on essential oils.

Practical Ways to Use Aromatherapy Safely

Diffusion One of the safest methods. Use an ultrasonic diffuser rather than a heat-based one (heat can degrade the oils). Run it for 30–60 minutes at a time in a well-ventilated room, not continuously.

Inhalation from a tissue  Add 1–2 drops to a tissue and inhale as needed. A great on-the-go option for nausea, sweet orange is a good one.

Bath Dilute 4–6 drops in a tablespoon of  a carrier oil before adding to the bath (oils don't dissolve in water alone and can cause skin irritation undiluted). Keep the water warm, not hot.

Massage  Use a 1% dilution in a carrier oil such as sweet almond, jojoba, or coconut. Avoid the abdomen in the first trimester. A foot, shoulder or back massage is a wonderful way to use aromatherapy in pregnancy.

Room spray  Dilute a few drops in water in a spray bottle for a gentle ambient scent. Shake well before each use.

A Few Blends to Try

For nausea: 2 drops mandarin (steam inhalation or tissue)

For sleep: 3 drops lavender + 1 drop chamomile (Roman) in a diffuser or on your pillowcase

For anxiety: 2 drops frankincense + 2 drops neroli + 1 drop sweet orange in a diffuser

For a relaxing bath: 3 drops lavender + 2 drops ylang ylang diluted in a tablespoon of carrier oil

Always Check with Your Midwife or Doctor

Aromatherapy is a complementary therapy, not a replacement for medical and midwifery care. If you have a high-risk pregnancy, pregnancy-induced hypertension, placenta praevia, or any complications, check with your healthcare provider or midwife trained to use essential oils before use. The same applies if you have skin sensitivities, allergies, or asthma.

Im a midwife who has additional training with essential oils in pregnancy, with a consultation I  can create a personalised blend tailored to your needs and stage of pregnancy.

Finally

Aromatherapy, used thoughtfully, can be a genuinely lovely support during pregnancy helping with nausea, anxiety, sleep difficulties and the general emotional ups and downs of those nine months. The key is being informed: knowing which oils are safe, using appropriate dilutions and listening to your body. If something doesn't feel right or a scent triggers nausea or headaches, stop using it.

As a side note, did you know cats are unable to metabolise essential oils?  If you have a feline friend at home dont use essential oils around them!

Your instincts during pregnancy are sharp. Trust them and enjoy the ritual.

This post is for informational purposes only and does not constitute medical advice. Always consult your midwife, GP, or a qualified aromatherapist before using essential oils during pregnancy.