Medical experts and herbalists agree that many herbs should be avoided during pregnancy. What follows is a list of herbs that generally draw a red flag. For a comprehensive list, refer to Herb Contraindications and Drug Interaction by Francis Brinker, ND (Eclectic Medical Publications, 1999). And of course, work with your physician to determine possible contraindications or harmful effects on your developing baby before taking any herbs or medications.

Ashwagandha (Withania somnifera). May trigger uterine contractions.

Bitter Melon (Momordica charantia). May stimulate the uterus.

Black and Blue Cohosh (Cimicifuga racemosa, Caulophyllum thalictroides). May trigger uterine contractions.

Chasteberry/Vitex (Vitex agnus castus). May stimulate the uterus.

Coltsfoot (Ussilago farfara). Subject to legal restrictions in some countries, coltsfoot may cause liver damage to developing baby.

Comfrey (Symphytum officinale). Contains pyrrolizidine alkaloids, which are toxic to the liver. May cause liver damage to developing baby.

Dong Quai (Angelica sinensis). May trigger uterine contractions.

Feverfew (Tanacetum parthenium). Promotes menstrual flow.

Ginseng, Panax (Panax ginseng). The active constituents in panax are similar in structure to steroid hormones.

Goldenseal (Hydrastis canadensis). May trigger uterine contractions.

Gotu Kola (Centella asiatica). May stimulate the uterus.

Juniper (Juniperus communis). Promotes menstrual flow.

Kava (Piper methysticum). Urinary antiseptic, stimulant.

Mistletoe (Viscum album). Potentially toxic. May trigger uterine contractions.

Pennyroyal (Mentha pulegium). Contains volatile oils. Powerful uterine stimulant.

Pokeweed (Phytolacca decandra). Potentially highly toxic.

Sage (Salvia officinalis). Estrogenic action and hormonal stimulant. Do not use therapeutically. Use only in food recipes.

Schisandra (Schisandra chinensis). May stimulate the uterus.

St. John's Wort (Hypericum perforatum). May alter estrogen levels.

Tansy (Tanacetum vulgare). Contains volatile oils. Potentially quite toxic.

Yarrow (Achillea millefolium). Contains volatile oils. Stimulates menstruation.

—D.B.