Perhaps the most commonly used CAM therapies in pregnancy are herbal remedies. These substances are available over-the-counter and do not require the use of an alternative practitioner. Because these preparations are accessible without prescription and because they are considered "natural," many people believe that they are harmless. On the contrary, many herbal preparations are very potent and can result in both beneficial and harmful effects, including dangerous interactions with other medications. Most have a measurable pharmaceutical effect. It should not be forgotten that many "mainstream" medications have a botanical basis, including digitalis (foxglove), taxol (Pacific yew), narcotics (opium poppy) and vincristine (Madagascar periwinkle).

Evaluation of herbal remedies is problematic due to the lack of rigorous scientific testing and the lack of governmental controls on the production and sale of these substances. Research on the efficacy and safety is difficult for many reasons. First is that fact that unlike synthetic preparations, herbs frequently contain more than one active substance.

It is difficult to discriminate from which substance any observed effect (or side effect) results. Indeed, the active ingredient may not be known. The motivation of pharmaceutical companies to fund the study of herbal remedies is lacking as the products cannot be patented. Lastly, research on herbal remedies suffers from the same problem that research on synthetic products does - pregnant/lactating women cannot ethically be included in randomized controlled trials due to safety concerns for the fetus/baby.

As a result of the lack of governmental control, preparations may differ markedly in quality. According to Rotblatt and Zimett (2002), "It is not uncommon for laboratory analyses of different brands of herbal medicines to find that important constituents vary by five, 10-, or even 40-fold; some contain no labeled product at all." This lack of standardization, in turn, affects research. The product available to the consumer may not be the same in potency or route of administration as the product used in a study that demonstrates efficacy of a particular herb.

Finally, in spite of efforts to standardize, the use of "natural" products is subject to the whims of Mother Nature. The growing conditions under which the herb is cultivated may significantly influence the concentration of active ingredients found in substances. Rotblatt and Zimett (2002) compare herbs to species of wine grapes that may vary in quality depending upon the winery or the year in which they are harvested.

These authors provide several suggestions for choosing a brand or type of herb that is most likely to be efficacious and safe:

1. Try to find products that match those used in controlled clinical trials. For instance, there are three forms of Echinacea that are used medicinally (E. purpurea, E. angustifolia, E. pallida). Different trials have used different forms. Three European products have been used in trials for acute upper respiratory tract infections (URI) symptoms; all include different extracts and were used in varying dosages. One also contains wild indigo and white cedar. Although it is difficult to find the exact product, it is worthwhile to try. (Rotblatt and Zimett provide the practitioner/consumer with a chart listing products that have been clinically tested in Europe that are currently marketed in the United States.)

2. Independent laboratory testing of herbal products is available. When possible, use products that have been tested and found to meet certain standards, in particular inclusion of the labeled plant, minimum concentrations of the essential ingredients and absence and lack of contaminants. The web site http://www.consumerlab.com provides some information on its homepage, and more complete information with an annual subscription. Consumer Reports has provided testing of some herbs, including kava, SAMe, saw palmetto and St. John's wort. Some ginseng products have been tested by the Ginseng Evaluation Program of the American Botanical Council.

3. Encourage patients to look for the initials "NF" signifying National Formulary on the label of herbal products. Standards for drugs and health products are established by the United States Pharmacopeia (USP). USP has developed standards for many herbal products, although compliance with these standards is voluntary. Those products that meet USP standards may use the initials "NF."

4. Some herbal products are marketed by traditional, large pharmaceutical firms, including GlaxoSmithKline, Boehringer Ingelheim and American Home Products. Most probably, these firms have the capacity and experience to provide a high quality product.

5. Critically investigate other manufacturers. Although no enforceable standards exist, producers of herbal remedies are frequently known by reputation for the quality of their products. Producers of botanicals may legitimately be queried regarding their procedures for standardization and quality control. Their products should identify, at the very least, manufacturer contact information as well as batch numbers and expiration date. Under the U.S. Dietary Supplement Health and Education Act, botanicals must be labeled with potential safety problems, potential side effects, contraindications and any special warnings such as interactions with other botanicals or chemicals.

Many herbs cross the placenta and into mother's milk. Research on the use of botanicals in pregnancy and lactation is sorely lacking. Even currently published, excellent texts are notably silent on the use of herbs in pregnancy. Most are listed as "contraindicated" in pregnancy and lactation (Feltrow andAvila, 2004), even those that have been used most extensively such as black cohosh. (The rationale given is its uterotonic effect; however, this is precisely why it is given - to stimulate labor.) The primary reason herbs are listed as contraindicated is that data are lacking on the use in pregnancy. However, there are some for which there is at least theoretical rationale. For instance, those with oxytocic effects should be avoided in early pregnancy. Some affect the immune system. Since pregnancy is a naturally hypo-immune state, it makes sense that one might avoid stimulation of the immune system.

Patients who choose to use herbal medications while pregnant or lactating should be advised to see a practitioner who has experience in the use of botanicals and who works frequently with pregnant patients. Many advise that a diagnostic work-up by a primary care provider precede the choice of either allopathic or CAM. The NCCAM web site has a specific section entitled "Selecting a Complementary and Alternative Medicine (CAM) Practitioner" which can be a useful tool for patients.