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Pregnancy & Infants
If You Are Pregnant: Herbs Are Drugs
Pregnant and breast-feeding women commonly consume herbal supplements, possibly because they believe that “natural products” are safer than drugs. However, even though some have been available for hundreds or thousands of years, we know little about their effects on the embryo, fetus, newborn, or nursing infant. Moreover, as unregulated products, we cannot easily determine the concentration, contents, and presence of contaminants. That’s why doctors have identified herbs to avoid when pregnant.
You may find detailed reviews of the 22 most commonly used herbs discussed here in “Drugs in Pregnancy and Lactation,” Briggs GG, Freeman RK, 10th ed., Philadelphia: Walters Kluwer Health, 2014).
Those who use these herbs rarely report dose, one of the two key factors that determine the risk of developmental toxicity (abnormal growth, structural anomalies, functional and/or neurobehavioral deficits, or death). In addition, all herbs contain multiple chemical compounds, few of which have been studied during pregnancy or lactation. Thus, with few exceptions, doctors should inform a woman who takes an herb in pregnancy of the unknown the risk to her developing baby.
Herbs to Avoid when Pregnant – Considered Contraindicated
Arnica
Dried arnica flowers, and sometimes the roots and rhizomes, are used topically for their anti-inflammatory and analgesic effects. No clinical evidence supports this use. Occasional topical use probably represents a low risk, but absorption may occur when applied to broken skin. The Food and Drug Administration has classified arnica as an unsafe herb. When used orally, it is considered a poison. It is a uterine stimulant and an abortifacient. Nevertheless, homeopathic formulations have promoted its use before and during labor for internal and external bruising of the mother and newborn. In Italy, it is one of the top 10 herbs taken by women (Pharmacoepidemiol. Drug Saf. 2006;15:354-9).
Black Seed/Kalanji
This herb has been used for thousands of year as a medicine, food, or spice. Because of this, it is unlikely that it causes teratogenesis. Nevertheless, its use to stimulate menstruation and its potential contraceptive properties suggest contraindications in pregnancy.
Blue Cohosh
Some of the components of this herb have shown to be teratogenic and toxic in various animal species, so one should avoid it in the first trimester. The herb has uterine stimulant properties used by nurse-midwives to stimulate labor, who most frequently use Blue Cohosh herbal preparations for this purpose. However, some sources believe that the potential fetal and newborn toxicity may outweigh any medical benefit (“PDR for Herbal Medicine,” 2nd ed., Montvale, N.J.: Medical Economics, 2000:109-10; “The Review of Natural Products,” St. Louis, MO: Facts and Comparisons, 2000).
Feverfew
As a homeopathic remedy, many have used feverfew for labor, menstrual disorders, potential miscarriage, and morning sickness; as an abortifacient; and for several other indications. Because of its antipyretic properties, some have called it “medieval aspirin.” Medical professionals have not quantified the doses used for these indications. Because of its emmenagogic (capable of provoking menstruation) activity, the herb should not be used in pregnancy.
Salvia divinorum
This herb has hallucinogenic effects and is used in certain regions of Mexico for healing and divinatory rituals. Some also believe it to have antidiarrheal properties. Rather than eaten, users either smoked or chew the herb, or ingest its juices. When taken orally, systemic effects depend upon absorption across the oral mucosa as the GI tract destroys the active ingredient. Persistent psychosis has been observed in people who smoked the herb, so it is contraindicated in pregnancy.
Valerian
Women may find a large number of preparations containing valerian available. People often use it as a sedative and hypnotic for anxiety, restlessness, and sleep disturbances, as well as several other pharmacologic claims. Because of the risk of cytotoxicity in the fetus and hepatotoxicity in the mother, one should avoid valerian during gestation.
Herbs to Use Only with Caution During Pregnancy
For the remaining 16 herbs, small, infrequent doses probably cause no harm to the mother, embryo, fetus, or newborn. Unfortunately very little research supports their safety, either. Nevertheless, as noted below, some of these herbs are best avoided during pregnancy.
Chamomile
Experts suspect excessive use of this herb has uterine stimulant, emmenagogic, and abortifacient properties. Although controversial, some nurse-midwives prescribe chamomile teas for the treatment of morning sickness. Because the plant sources of the herb contain coumarin compounds, ingesting chamomile by pregnant women with coagulation disorders is a concern. However, people have used the herb for thousands of years. Therefore the risk of harm, at least from occasional use, must be very rare.
Echinacea
Many people use echinacea topically to enhance wound healing and systemically as an immunostimulant. An IV formulation is used in Germany but is not available in the United States. It also has been recommended to assist in the prevention or treatment of viral upper respiratory tract infections. Its use in pregnancy is limited to one small study.
Evening primrose oil
The oil contains two essential fatty acids: cis-linoleic and gamma-linolenic acid. In a national survey of nurse-midwives, they cited it as the most frequently used herbal preparation for the induction of labor. No reported adverse effects exist in the fetus or newborn from this use. The doses used varied widely and included both oral and vaginal routes of administration. In addition, the oil has been used for rheumatoid arthritis and diabetic neuropathy, but there are no reports of these uses in pregnancy.
Garlic
Garlic has been used for food flavoring since ancient times and appears to safe for pregnancy. Some components cross the placenta, as shown by garlic odor in the amniotic fluid and on the newborn’s breath. Very high doses have the potential to induce menstruation or uterine contractions, but apparently these effects have not been reported.
Ginger
No reports of ginger-induced developmental toxicity have been located. Ginger has been used as antiemetic for nausea and vomiting of pregnancy.
Ginseng
The root is the most important part of this plant that is found throughout the world and has been used in medicine for more than 2,000 years. Proponents of ginseng promote it for multiple pharmacologic effects, including adaptogenic, CNS, cardiovascular, endocrine, ergogenic, antineoplastic, and immunomodulatory effects.
Studies have reported hypertension and hypoglycemia in nonpregnant patients, but not in the limited human pregnancy data. A brief 1991 study compared 88 women who took the herb during pregnancy with 88 controls. The study found no difference between the groups with regard to the mode of delivery, birth weight, low birth weight (< 2,500 ), preterm delivery (< 37 weeks), low Apgar score (< 7), stillbirths, neonatal deaths, or maternal complications (Asia Oceania J. Obstet. Gynaecol. 1991;17:379-80).
Ginkgo Biloba
Limited animal reproduction data suggest low risk, but there no reported human pregnancy experience exists. Nevertheless, this ancient herbal preparation commonly treats organic brain syndrome, circulatory disorders, asthma, vertigo, and tinnitus. Because of its widespread use, a major teratogenic effect would not have escaped notice. However, more subtle or low-incidence toxic effects may not have been detected.
Kudzu
No human or animal data regarding pregnancy have been located. People have consumed Kudzu for more than 2,500 years for the treatment of alcohol hangover, drunkenness, alcoholism, muscle pain, and measles. Many of its chemical constituents can be found in foods. Nevertheless, pregnant patients should avoid high, frequent doses.
Nutmeg
Though a commonly used spice, high doses of nutmeg can produce toxicity. A chemical in the seeds, myristicin, causes toxicity via anticholinergic properties. A woman at 30 weeks’ gestation misread a recipe and used a whole grated nutmeg rather than 1/8 teaspoon when making cookies. When she ate a cookie, she experienced sinus tachycardia, hypertension, and a sensation of impending doom. The fetus had tachycardia, and received an atropine-like poisoning diagnosis. After about 12 hours, both mother and fetus made an uneventful recovery and a healthy infant was born at term.
Passion Flower
The name of this herb may refer to about 400 species of the genus Passiflora. It is available in both oral and topical forms and is used for nervousness, neuralgia, insomnia, pain, asthma, seizures, burns, hemorrhoids, and menopausal complaints. As with many herbs, it contains a large number of chemicals, none of which have undergone reproductive testing. No located reports describe the use of this herb in human pregnancy. However, because of its uterine stimulant properties, one would do well to avoid oral formulation in pregnancy.
Peppermint
This popular flavoring appears to be harmless for the mother and developing baby when they ingest low, recommended doses. Numerous topical and oral formulations of peppermint oil are available. High oral doses, however, can cause significant toxicity, including death. During pregnancy, ingestion of more than the recommended doses is unsafe because of possible emmenagogic and abortifacient properties.
Pumpkin Seed
This herb, when used as a food, appears harmless for the mother and embryo-fetus. However, no reports describing its use in pregnancy have been located. High doses, such as those used in traditional medicine or in eating disorders, contain the potential for toxic effects from the many chemicals these seeds contain.
Raspberry Leaf
Pregnant women commonly use raspberry leaf tea. Nurse-midwives often prescribe the tea to treat nausea and vomiting and as a uterine tonic to shorten labor. A double-blind, randomized, placebo-controlled study evaluated the effect of raspberry leaf tablets (2 tablets/day) on pregnancy outcomes. Compared with controls, studies found no differences for length of labor or stages of labor, mode of delivery, admission to the neonatal intensive care unit, Apgar score, and birth weight (J. Midwifery Womens Health 2001;46:51-9).
Safflower
Commonly used in cooking, some also give safflower oil for its laxative action. No reports describe the use of the herb in pregnancy. It is doubtful if such use would have any adverse effect on a pregnancy. Although suggestions of abortifacient and emmenagogic effects exist, no evidence supports these effects when used as a food.
St. John’s Wort
No toxicity in pregnant humans has been reported. The use of the herb is widespread and dates back thousands of years. Thus, it is doubtful that the herb is a major teratogen or causes other elements of developmental toxicity. People use the herb for the management of anxiety, depression, insomnia, inflammation, and gastritis. They also use it as a diuretic and, topically, for the treatment of hemorrhoids and enhanced wound healing.
Yohimbine
Studies have not reported the use of this herb in human pregnancies. Its uses include as an aphrodisiac and for weight loss, sexual dysfunction, and the treatment of orthostatic hypotension. Although it has no Food and Drug Administration–sanctioned indications, it is also available by prescription for male erectile dysfunction. Due to the lack of data regarding pregnancy, the herb is best avoided during pregnancy.
Conclusion and Nursing
While we have more data on herbs to avoid during pregnancy, there are few data regarding the effects of the above herbs on a breast-feeding infant. Depending upon the herb, nursing infants will be exposed to many chemical compounds. For those herbs used as food, nursing is probably safe. The safety of the other herbs during lactation is unknown. However, toxicity has been reported in a 9-day-old term infant whose mother was taking arnica (Clin. Toxicol. 2009;47:726, abstract 120). The infant presented with lethargy, decreased milk intake, anemia, and jaundice but recovered with treatment. After the mother stopped the herb and resumed nursing, professionals noted no further problems in the infant.
Drugs, Pregnancy, and Lactation: Herbs
By: GERALD G. BRIGGS, B.PHARM., FCCP October 23, 2014
Mr. Briggs is a pharmacist clinical specialist at the outpatient clinics of Memorial Care Center for Women at Miller Children’s Hospital in Long Beach, Calif.; clinical professor of pharmacy at the University of California, San Francisco; and adjunct professor of pharmacy at the University of Southern California, Los Angeles, and Washington State University, Spokane. He also is coauthor of “Drugs in Pregnancy and Lactation,” and coeditor of “Diseases, Complications, and Drug Therapy in Obstetrics.” He had no relevant financial disclosures.
reposted by Heather Knott, RN-IBCLC
