Safe as a Baby: Is There a Case for the Safety of Herbs During Pregnancy?

Source: Nordeng H, Havnen GC. Use of herbal drugs in pregnancy: A survey among 400 Norwegian women. Pharmacoepidemiol Drug Saf 2004;13:371-380.

Abstract: The authors interviewed 400 postpartum women at Ulleval University Hospital in Oslo, Norway, about use of herbs during pregnancy. The researchers found that 36% of the pregnant women had used herbal drugs during pregnancy with an average of 1.7 products per woman. The proportion of women using herbal drugs increased throughout the first, second, and third trimesters. The most commonly used herbs were echinacea, iron-rich herbs, ginger, chamomile, and cranberry. Among the women having used herbs in pregnancy, 39% had used herbs that were possibly harmful or herbs where information about safety in pregnancy was missing. Herbal galactagogues had been used by 43% of the women who had breastfed a prior child during their breastfeeding period. The authors concluded that the widespread use of herbal drugs during pregnancy indicates an increased need for documentation about the safety of herbal drugs in pregnancy. To meet the needs of pregnant women, it is necessary for health care personnel to have knowledge about herbal drugs during pregnancy.

Source: Belew C. Herbs and the childbearing woman. Guidelines for midwives. Nurse Midwifery 1999;44:231-252.

Abstract: The use of herbs to promote health or treat disease has become popular, and midwives increasingly encounter questions from childbearing clients regarding herbs. This article provides an overview of key concepts regarding the incorporation of herbs into clinical practice and discusses the preparation and administration of herbal treatments for common concerns of pregnancy. Safety issues are emphasized throughout.

Comments by Mary L. Hardy, MD

Health care providers know that up to one-third of the adult population uses herbal medicine, but most have not realized how often pregnant women use herbs. Estimates range from a low of 7% to a high of 36% for pregnant women.1-5 If the patient is also cared for by a naturopath or a midwife, this percentage might be considerably higher.6,7 All health care providers should be committed to the goal of "First, do no harm," but conventionally trained practitioners may have trouble finding credible information to aid them in advising pregnant patients. This month we will look at an abstract that describes herb use in a pregnant population and at what information is available in the literature regarding safe use of herbal medicine in pregnancy.

Nordeng and Haven interviewed 400 Norwegian women within three days of giving birth about their use of herbal medicine during their pregnancies.4 More than one-third of the women reported using herbs (36%) and most used more than one product (1.7 on average). Use of herbal medicine was lowest in the first trimester and highest in the third trimester. The most commonly used herbs and their indications were echinacea (23%, for cold), iron-rich herbs (12%, for low iron), ginger (10%, for nausea), chamomile (9%, for calming effect), and cranberry (8%, for urinary tract infections). Almost half (46.5%) of the women using herbs during pregnancy were recommended to do so by friends and family. Another 23% tried herbs on their own initiative and an additional 20% relied on information from books or other media. Only 12% received information from health care personnel; this was 2% less than the number (14%) who relied on an herbal store for advice.

The Norwegian survey appears comparable to a survey of pregnant women at an American academic medical center.5 In the U.S. survey, only 13% used herbs and again the most common herb was echinacea, closely followed by ginger and a pregnancy tea. What does the literature have to say about the safe use of herbs in pregnancy?

Although a number of safety studies in pregnancy have been conducted in animals, there is almost no literature published on humans. Two bioavailability studies and a handful of clinical trials are all that has been published to date. Herbal constituents have been found in both breast milk8 and placental blood.9 One woman used 900 mg of a standardized St. John’s wort preparation; only hyperforin was found in her breast milk, in low levels. When the infant’s serum was examined, neither hyperforin nor hypericin were detectable.

Observational studies have been done on groups of pregnant women who already were found to be taking common herbal supplements. Since randomized trials in pregnant women are unlikely where there is a potential for adverse effects, observational trials will give us our most reliable evidence for safety or risk. The Toronto-based Motherisk Program, a group that assesses risk during pregnancy from both herbs and drugs, has published a prospective controlled study on the use of echinacea in pregnancy.10 They enrolled 206 women who reported echinacea use to a call-in service. These women were matched with a similar cohort who had not used echinacea, and both groups were followed until delivery. No difference in pregnancy outcomes or fetal malformation was reported between groups. This very experienced group concluded that there was no evidence for teratogenic risk of using echinacea even during the first trimester. One of the few randomized trials conducted on herbal use in pregnancy examined the safety and effectiveness of raspberry leaf tea to shorten labor.11 The study also collected safety data; no adverse effects on pregnancy outcome or fetal development were noted.

Given the scarcity of data in the conventional literature, medical practitioners should avail themselves of the expertise of herbal practitioners and midwives who have experience in using common herbal substances during pregnancy. One of the most accessible references for authoritative information on safety is the Botanical Safety Handbook.12 This reference, prepared by a group of senior herbalists, lists a wide array of herbs and rates their safety for use in pregnancy and lactation. Representing the midwife’s perspective, Cindy Belew has written a well-organized article about herbal use in pregnancy.13 It is especially useful for health care practitioners as it provides a general review of herbal principles and practice as well as specific information on safety.

Herbal use is popular in pregnancy, just as it is in the general population. Patients tend to prefer herbal remedies over medications for common conditions, perceiving herbs to be safer. Research in this area is beginning to provide some useful data, such as the apparent safety of echinacea during pregnancy, but clearly much more work remains to be done. As health care providers, we have to be ready to counsel our patients in advance of definitive research. The fact that so few patients include health care providers as sources of information regarding herbal use in pregnancy creates a potentially risky situation for them. We need to actively question our patients about use of herbs and dietary substances during pregnancy. To be prepared for these discussions and credible to our patients, we must educate ourselves using all available information. Since conventional sources are limited, we should reach out to our alterative colleagues, who have significant clinical experience in these areas. In this way we can help our patients achieve the best possible outcome from their pregnancies.

Dr. Hardy, Associate Director, UCLA Center for Dietary Supplement Research: Botanicals Medical Director, Cedars-Sinai Integrative Medicine Program Los Angeles CA, is on the Editorial Advisory Board of Alternative Therapies in Women’s Health.

References

1. Hepner DL, et al. Herbal medicine use in parturients. Anesth Analg 2002;94:690-693; table of contents.

2. Tsui B, et al. A survey of dietary supplement use during pregnancy at an academic medical center. Am J Obstet Gynecol 2001;185:433-437.

3. Pinn G, Pallett L. Herbal medicine in pregnancy. Complement Ther Nurs Midwifery 2002;8:77-80.

4. Nordeng H, Havnen GC. Use of herbal drugs in pregnancy: A survey among 400 Norwegian women. Pharmacoepidemiol Drug Saf 2004;13:371-380.

5. Tsui B, et al. A survey of dietary supplement use during pregnancy at an academic medical center. Am J Obstet Gynecol 2001;185:433-437.

6. Einarson A, et al. Attitudes and practices of physicians and naturopaths toward herbal products, including use during pregnancy and lactation. Can J Clin Pharmacol 2000;7:45-49.

7. McFarlin BL, et al. A national survey of herbal preparation use by nurse-midwives for labor stimulation. Review of the literature and recommendations for practice. J Nurse Midwifery 1999;44:205-216.

8. Klier CM, et al. St. John’s wort (Hypericum perforatum)—is it safe during breastfeeding? Pharmacopsychiatry 2002;35:29-30.

9. Petty HR, et al. Identification of colchicine in placental blood from patients using herbal medicines. Chem Res Toxicol 2001;14:1254-1258.

10. Gallo M, et al. Pregnancy outcome following gestational exposure to echinacea: A prospective controlled study. Arch Intern Med 2000;160:3141-3143.

11. Simpson M, et al. Raspberry leaf in pregnancy: Its safety and efficacy in labor. J Midwifery Womens Health 2001;46:51-59.

12. McGuffin M, et al, eds. Botanical Safety Handbook. Boca Raton, FL: CRC Press; 1997.

13. Belew C. Herbs and the childbearing woman. Guidelines for midwives. Nurse Midwifery 1999;44:231-252.