Herbs to Avoid During Pregnancy

A literature search of the ethnopharmacology of plants used for their abortifacient
or uterine stimulating actions provides a long list of plants to avoid.
According to Marderosian and Liberti in their useful but rather biased book
`Natural Product Medicine‘, 565 species from 125 families have such
effects.

These otherwise extremely useful remedies often share chemistry that in
some way irritates the placenta or causes muscular contractions in the uterus.
Limiting ourselves to those plants most often encountered in western Phytotherapy,
the following groupings can be identified :

Bitters

From the material concerning bitters already covered, it is clear that the
general metabolic stimulation and especially that of smooth muscle and the
emmenagogue results, are contra-indicated during pregnancy. All strong bitters
should be excluded, with especial attention to :

Artemisia abrotanum Southernwood

Artemisia absinthium Wormwood

Artemisia vulgare Mugwort

Berberis vulgaris Barberry

Chelidonium majus Celandine

Hydrastis canadensis Golden Seal

Ruta graveolens Rue

Tanacetum parthenium Feverfew

Tanacetum vulgare Tansy

Alkaloid containing plants

Alkaloids are a diverse group of secondary plant constituents that have
a wide range of pharmacological impact upon the body. The stronger representatives
are to be avoided, including the caffeine containing social drugs Coffee
and Tea. These include :

Berberis vulgaris Barberry

Colchicum autumnale Autumn crocus

Hydrastis canadensis Golden Seal

Podophyllum peltatum Mandrake

Sanguinaria canadensis Blood root

Sarothamnus scoparius Broom

Oil containing plants

Many of the essential oils can have a devastating impact on the placenta
and foetus is taken internally during pregnancy. Avoid all Essential
oils internally. However, the whole plant that the oil was distilled
from will usually be fine if used in moderation. Important exceptions are:

Juniperus communis Juniper

Mentha pulegium Pennyroyal

Myristica officinalis Nutmeg (in large amounts)

Thuja occidentalis Arbor vitae

Anthraquinone Laxatives

The strong herbal laxatives often owe their effects to the presence of anthraquinones
that stimulate peristalsis in the bowel. They may have a similar stimulating
impact upon the uterus. If a laxative is needed during pregnancy it should
be either a bulk or hepatic laxative. Please refer to appropriate section
for more information.

Cassia senna Senna

Rhamnus catharticus Purging Buckthorn

Rhamnus frangula Alder Buckthorn

Rhamnus purshiana Cascara Sagrada

Others

There are other plants that should be avoided which do not fit into such
convenient categories. Some are listed here. Male Fern is an example of
an anthelmintic remedy for the treatment of worm infestations.