The Use of Herbs During Pregnancy and Lactation: A Balancing Act

Dr. Liz Bartman

The Use of Herbs During Pregnancy and Lactation: A Balancing Act

When it comes to using herbs during pregnancy, the conversation is not necessarily about the inherent dangers of these plants. Instead, it’s more about the lack of substantial research to confirm their safety. Many herbs have been used for centuries in both Western and Eastern medicine to support fertility and pregnancy. However, without the rigorous testing and safety data required by U.S. standards, particularly by the FDA, it becomes difficult to endorse their use during pregnancy.

The Role of Herbs in Pre-Pregnancy Support

Before pregnancy, herbs can play an essential role in supporting reproductive health. They can aid in follicular development, regulate the hypothalamic-pituitary-ovarian (HPO) axis, and even assist with endometrial implantation. However, once pregnancy is confirmed, the function of many of these herbs shifts. They no longer support the key aspects of early pregnancy, and in some cases, they may even pose risks.

One notable exception to this is DHEA (Dehydroepiandrosterone), a supplement often used to improve ovarian function. While it’s beneficial before pregnancy, it’s classified as teratogenic, meaning it can cause developmental defects in the fetus. As soon as pregnancy is known, DHEA should be discontinued immediately.

Why the First Trimester is Critical

The first trimester of pregnancy is particularly sensitive for the developing fetus. During this time, the foundations of all major organs are laid, and exposure to certain substances—including herbs—can potentially disrupt this process. For this reason, the use of most medicinal herbs is not recommended during the first trimester. Some herbs can induce uterine contractions, stimulate menstrual flow, or cause miscarriage, while others are teratogenic or poisonous at any stage of pregnancy.

Herbs to Avoid in the First Trimester

Some herbs known to have contraindications in early pregnancy include:

• Angelica (Dong Quai): Can stimulate uterine contractions.
• Black Cohosh: Often used for menopausal symptoms but may induce contractions.
• Chamomile: While often used as a calming tea, it may stimulate uterine activity.
• Peppermint: Generally considered safe in small amounts, but it may lead to uterine stimulation if taken in large doses.

Other herbs, such as Artemisia vulgaris (Mugwort), Calendula, and Myrrh, also fall into this category and should be avoided, especially in the early stages of pregnancy.

A Longer List of Herbs Contraindicated Throughout Pregnancy

Beyond the first trimester, there’s an even longer list of herbs that should be avoided for the entirety of pregnancy. These include:

• Aloe Barbadensis (Aloe Vera): Can cause uterine contractions and electrolyte imbalances.
• Cannabis Sativa (Marijuana): Known to affect fetal development and should be strictly avoided.
• Pennyroyal: Highly toxic and known to cause severe health issues, including potential miscarriage.

These and many other herbs, including Cinnamon (in high doses) and St. John’s Wort, should be used with extreme caution or avoided altogether during pregnancy due to their potential risks to both the mother and baby.

Safe Herbal Practices During Pregnancy

Despite the long list of herbs to avoid, there are still some safe options that can provide support during pregnancy. For example:

• Red Clover: This herb is often recommended as a tea and is known for its gentle support of pregnancy.
• Ginger: Especially helpful for nausea in the early stages of pregnancy, ginger tea is a safe and effective option.

In general, when using herbs during pregnancy, it’s best to focus on those with known nutritional value and to consume them in small, food-based doses. Spices like ginger and peppermint can usually be consumed safely in moderate amounts.

The Use of Natural Supplements During Lactation

Once the baby is born, many mothers turn to natural supplements to support overall wellness. However, just like during pregnancy, caution must be exercised during breastfeeding. Natural products can pass into breast milk, potentially affecting the nursing infant.

Guidelines for Using Natural Supplements While Breastfeeding

Here are some key considerations for safely using natural supplements during lactation:

1. Start with Low Doses: Introduce herbs in low to moderate amounts, as even herbs considered safe in low doses can become problematic in high quantities.
2. Use One Herb at a Time: This allows mothers to identify any negative reactions in their infants. Some herbs can change the taste of breast milk or cause digestive issues like gas or spitting up.
3. Be Cautious with Phytoestrogens: Herbs with phytoestrogen activity (such as licorice or fenugreek) can sometimes diminish milk supply. Avoid these, especially in the first six weeks postpartum, when milk supply is still being established.
4. Wait Until Supply is Established: After 12 weeks postpartum, milk supply is less sensitive to external influences. At this point, many herbs and supplements can be used more freely.
5. Watch for Vitamin Buildup: Water-soluble vitamins, such as B vitamins, are usually safe as they are excreted through urine. Fat-soluble vitamins (like A, D, E, and K) can build up and should be dosed carefully to avoid toxicity in the infant.

Safe vs. Risky Herbs While Breastfeeding

When assessing the safety of an herb or supplement, the following categories can guide decision-making:

• Safe: Has no known toxicity and minimal transfer to breast milk. Examples include ginger and nettle.
• Low Risk: Generally safe but with limited research. Stick to typical dosing.
• Probably Safe: Limited data but no known toxicity. Use caution with dosing.
• Caution Advised: Known toxicity at certain doses or potential to reduce milk supply.
• Avoid: Known to be unsafe for either the infant or the mother, such as goldenseal, sage, and thyme in large quantities.

While herbs and natural supplements offer a range of benefits, their use during pregnancy and breastfeeding must be approached with caution. The lack of sufficient research on many herbs means that erring on the side of caution is the safest route. 

Medical Summary of Contraindicated Herbs During Pregnancy

Certain herbs are contraindicated during pregnancy due to their potential to cause adverse effects, such as uterine contractions, miscarriage, teratogenic effects, or toxicity to the mother and fetus. Below is a list of herbs that should be avoided during pregnancy, categorized based on their risks.

1. Uterine Stimulants & Abortifacients

These herbs may cause uterine contractions, stimulate menstrual flow, or induce labor, increasing the risk of miscarriage or preterm birth.

• Angelica spp (Dong Quai): Uterine stimulant, increases miscarriage risk.
• Black Cohosh (Cimicifuga racemosa): Uterine stimulant, induces labor.
• Pennyroyal (Mentha pulegium): Potent uterine stimulant, linked to miscarriage.
• Mugwort (Artemisia vulgaris): Uterine stimulant, abortifacient.
• Rue (Ruta graveolens): Uterine stimulant, abortifacient.
• Sage (Salvia officinalis): Uterine stimulant in large amounts, possible abortifacient.
• Parsley (Petroselinum crispum, seeds): Uterine stimulant, linked to miscarriage.

2. Teratogenic Herbs

These herbs may cause developmental abnormalities or defects in the fetus.

• DHEA (Dehydroepiandrosterone): Teratogenic, should be discontinued immediately once pregnancy is confirmed.
• Wild Cherry (Prunus serotina): Teratogenic, toxic.
• Castor Bean (Ricinus communis): Contains ricin, which is highly toxic.
• Betel Nut (Areca catechu): Teratogenic effects and toxicity.
• Tobacco (Nicotiana tabacum): Known teratogen with harmful effects on fetal development.

3. Toxic Herbs

These herbs are known to be toxic to either the mother or the fetus and should be strictly avoided.

• Poison Hemlock (Conium maculatum): Extremely toxic, can cause paralysis and death.
• Mandrake (Podophyllum peltatum): Highly toxic, teratogenic, and abortifacient.
• Arnica (Arnica montana): Toxic if taken internally.
• Cocaine (Erythroxylum coca): Neurotoxic and teratogenic, causes severe fetal harm.
• Opium Poppy (Papaver somniferum): Narcotic properties, highly toxic to the fetus.

4. Herbs that Induce Menstrual Flow or Abort Pregnancy

These herbs may induce menstruation or cause the uterus to contract, leading to the risk of abortion.

• Aloe Vera (Aloe barbadensis, internal use): Laxative effect can stimulate uterine contractions.
• Cinnamon (in high doses): Stimulates menstrual flow and uterine contractions.
• Juniper (Juniperus communis): Can stimulate uterine contractions, linked to miscarriage.
• Tansy (Tanacetum vulgare): Known abortifacient, induces uterine contractions.

5. Herbs with Hormonal Effects

Herbs that may interfere with hormonal balance during pregnancy, affecting fetal development.

• Licorice (Glycyrrhiza glabra): Alters cortisol levels, potentially harmful to pregnancy.
• Hops (Humulus lupulus): Estrogenic activity, avoid due to hormone disruption.
• Ginseng (Panax ginseng): Hormonal effects, not recommended during pregnancy.

6. Herbs to Avoid Throughout Pregnancy

These herbs carry risks that make them unsafe for use at any stage of pregnancy.

• Yarrow (Achillea millefolium): Uterine stimulant, abortifacient.
• Wormwood (Artemisia absinthium): Neurotoxic, uterine stimulant.
• Pleurisy Root (Asclepias tuberosa): Uterine stimulant, potentially toxic.
• Sassafras (Sassafras albidum): Contains safrole, a carcinogen and uterine stimulant.
• Senna (Cassia angustifolia): Laxative, can stimulate uterine contractions.
• Motherwort (Leonurus cardiaca): Uterine stimulant, avoid throughout pregnancy.
• Blue Cohosh (Caulophyllum thalictroides): Uterine stimulant, linked to birth complications.
• St. John’s Wort (Hypericum perforatum): Limited research but potentially affects fetal development.

General Guidelines for Herbal Use During Pregnancy

• First Trimester Sensitivity: Avoid most medicinal herbs during the first trimester, as this is the most critical time for fetal organ development.
• Herbs with Nutritional Value: Focus on herbs that provide nutritional support in food-level doses, such as ginger (for nausea) or red clover (as a tea).
• Avoid High Doses: Even with generally safe herbs, avoid high doses during pregnancy.
• Consult a Healthcare Provider: Always consult a healthcare provider before using any herbs during pregnancy, as individual cases may vary.

Herbs are powerful natural substances, and during pregnancy, their effects can be unpredictable. While some may offer benefits, many have the potential to cause harm. For this reason, it is essential to approach herbal use with caution and avoid those known to pose risks to the developing fetus.

When considering the use of herbs during lactation, it’s crucial to evaluate their safety for both the breastfeeding mother and the infant. Some herbs are generally recognized as safe (GRAS) when used in moderation, while others may require caution due to limited data or potential adverse effects.

Common Herbs Generally Considered Safe in Lactation

1. Fenugreek (Trigonella foenum-graecum)
   • Use: Often used to promote lactation (galactagogue).
   • Safety: Generally considered safe when used in moderation. However, it may cause gastrointestinal upset in both mother and infant, and in rare cases, it can affect blood sugar levels.
   • Caution: Women with diabetes or peanut allergies should be cautious, as fenugreek may lower blood glucose and is part of the legume family.
2. Ginger (Zingiber officinale)
   • Use: Commonly used for nausea, inflammation, and digestion.
   • Safety: Safe in food amounts, and likely safe in moderate medicinal doses during lactation.
   • Caution: Large amounts may increase the risk of bleeding, particularly in those on anticoagulant therapy.
3. Fennel (Foeniculum vulgare)
   • Use: Traditionally used to increase milk supply and reduce infant colic.
   • Safety: Generally safe when used as a spice or in small doses. Excessive consumption may lead to possible estrogenic effects and gastrointestinal issues.
4. Chamomile (Matricaria chamomilla)
   • Use: Often used for its calming effects and to soothe gastrointestinal discomfort.
   • Safety: Safe in moderate amounts, typically as tea. Large doses should be avoided, and individuals with ragweed allergies may experience allergic reactions.
5. Blessed Thistle (Cnicus benedictus)
   • Use: Frequently combined with fenugreek to increase milk supply.
   • Safety: Generally regarded as safe in lactation when used in moderate doses.
   • Caution: Can cause gastrointestinal upset, so excessive use should be avoided.
6. Milk Thistle (Silybum marianum)
   • Use: Known for supporting liver health and potentially increasing milk production.
   • Safety: Considered safe in lactation, though evidence on its efficacy as a galactagogue is limited.
7. Nettle (Urtica dioica)
   • Use: Traditionally used to boost milk supply and provide vitamins and minerals.
   • Safety: Safe in moderation but should be used cautiously due to potential diuretic effects.

Herbs to Use with Caution in Lactation

1. Peppermint (Mentha piperita)
   • Use: Used for digestive issues, but large doses may reduce milk supply.
   • Caution: Safe in small amounts but avoid concentrated peppermint oil or excessive use during lactation if concerned about milk supply.
2. Sage (Salvia officinalis)
   • Use: Commonly used for sore throats or as a culinary herb.
   • Caution: Contains compounds that can reduce milk supply when used in large amounts. Occasional culinary use is generally safe.
3. Echinacea (Echinacea purpurea)
   • Use: Often used to boost the immune system.
   • Caution: Limited data on safety in breastfeeding, but occasional use is likely safe. Long-term or excessive use should be avoided due to potential immune system effects.
4. Garlic (Allium sativum)
   • Use: Used for immune support and cardiovascular health.
   • Caution: Generally safe, but large amounts may alter the taste of breast milk, potentially leading to infant fussiness.

Herbs to Avoid in Lactation

1. Ginseng (Panax ginseng)
   • Reason: May have estrogenic effects and is not recommended due to insufficient safety data in breastfeeding.
2. St. John’s Wort (Hypericum perforatum)
   • Reason: While used for depression, it may reduce milk supply and interact with many medications, including antidepressants.
3. Aloe Vera (Aloe barbadensis)
   • Reason: Internal use of aloe vera gel can cause gastrointestinal distress and should be avoided during breastfeeding.

General Recommendations

• Prefer herbs with well-established safety profiles and use them in moderate amounts.
• Avoid high doses or long-term use of herbs without professional guidance.
• Be cautious with herbal teas and supplements, as their concentrations can vary widely.

Herbal use in lactation requires careful consideration to balance potential benefits with safety for both mother and child.

Resources for more information can be found here: 

1. American Pregnancy Association (APA): The APA provides guidelines on herbal use during pregnancy and lists several herbs that are considered unsafe. They emphasize the importance of consulting with healthcare professionals before using any herbs or supplements.
   • Website: American Pregnancy Association
2. National Center for Complementary and Integrative Health (NCCIH): This U.S. government site provides research-based information on the safety and efficacy of various herbs, including warnings about contraindications during pregnancy.
   • Website: NCCIH Herbs at a Glance
3. Drugs and Lactation Database (LactMed): A resource from the National Library of Medicine that offers data on the effects of drugs and herbs during breastfeeding, which is closely related to their safety during pregnancy.
   • Website: LactMed
4. Mayo Clinic: Mayo Clinic provides an evidence-based list of herbs and supplements that are considered unsafe during pregnancy, with explanations of potential risks.
   • Website: Mayo Clinic – Herbs and Pregnancy
5. World Health Organization (WHO): The WHO discusses the general safety of herbal medicine use, including during pregnancy, and emphasizes the need for more research and caution in certain populations, such as pregnant women.
   • Website: WHO Herbal Medicine Safety
6. Herbal Safety by the University of Texas at El Paso and the University of Southern California: This resource offers a comprehensive guide on the use of medicinal herbs, with a specific section on pregnancy.
   • Website: Herbal Safety
7. MedlinePlus (U.S. National Library of Medicine): Offers detailed drug and herb information, including safety warnings and potential side effects for pregnant women.
   • Website: MedlinePlus Herbs
8. The Essential Guide to Herbal Safety (Book): Written by Simon Mills and Kerry Bone, this text is a highly recommended resource on the safety and toxicity of herbs, including contraindications during pregnancy.
   • ISBN: 978-0443071713
9. The Natural Pregnancy Book and Natural Health after Birth: both books were written by Aviva Romm, MD. They discuss the historic use and current suggestions for healthy pregnancy and post-pregnancy support, and include lifestyle suggestions and stories to support women through their pregnancy journey.  
   • Website: https://avivaromm.com/books/