Neonatal Congestive Heart Failure Associated with Maternal Use of Blue Cohosh

Neonatal Congestive Heart Failure Associated with Maternal Use of Blue Cohosh

Reviewed by: R. Reichert

Reference: Jones TK, Lawson BM. Profound neonatal congestive heart failure caused by maternal consumption Of blue cohosh herbal medication. J Pediatr 1998; 132:550-52.

Summary: A 36 year old woman in the last trimester of pregnancy was instructed by her midwife to consume one tablet of blue cohosh (Caulophyllum thalictroides) daily (amount of blue cohosh per tablet is not given) one month before delivery. The mother had no history of alcohol, tobacco, or illicit drug use (including cocaine). She was on thyroid replacement therapy, but blood levels of thyroid hormone throughout her pregnancy were reported to be within normal laboratory parameters. The mother elected to increase the recommended dose of blue cohosh from one to three tablets daily for the next three weeks and reported experiencing an increase in uterine contractions and a decrease in fetal activity. This resulted in spontaneous onset of labor and delivery of an infant who was critically ill.

Physical examination of the infant revealed poor peripheral pulses and perfusion with a gallop rhythm, mitral regurgitation murmur, and hepatomegaly. The chest x-ray revealed cardiomegaly and pulmonary edema. Electrocardiogram results indicated evidence of an acute anterolateral myocardial infarction with deep Q waves and fiat or inverted T waves. Echocardiogram results showed extensive regional wall abnormalities with profound hypokinesis of the left posterior wall and moderate hypokinesis of the interventricular septum. Right ventricular anterior wall motion was well preserved. Severe mitral valve regurgitation was also present. Moreover, there was severe pulmonary hypertension believed to be secondary to the left ventricular dysfunction. A moderately sized patent ductus arteriosus with a low velocity bidirectional pattern of shunt flow was also seen on echocardiogram.

The infant was initially stabilized using 10 ppm of nitric oxide, along with tolbutamide, high-dose vasopressor support with dopamine, and high-frequency ventilation. After 21 days the infant's condition stabilized and he underwent extubation. Cardiovascular support continued with digoxin, diuretics and captopril. Follow- up echocardiograms ruled out a congenital coronary artery anomaly that could account for his condition. Gradual resolution of his mitral regurgitation and pulmonary hypertension were noted over his 31 day hospitalization. Two years later, the patient is reportedly doing well with normal growth and development for his age. However, his cardiomegaly along with a slight reduction in left ventricular function have persisted, necessitating continued therapy with digoxin.

Comments/Opinions: This case report by Drs. T. K. Jones and B. M. Larson from the Children's Heart Center in Seattle, Washington, suggests that maternal ingestion of the herb blue cohosh can lead to severe infantile cardiac dysfunction. Blue cohosh, the authors point out, contains several phytochemicals that could contribute to cardiac dysfunction. These include the alkaloid caulophyllin (= methylcytisine), which is pharmacologically similar to nicotine and, in toxic quantities, can lead to tachycardia, hypotension, and coronary vasoconstriction. Moreover, the herb also contains the glycosides caulosaponin and caulophyllosaponin. A crystalline glycoside extracted from blue cohosh has been shown to increase the degree and rate of uterine contraction for 90 minutes both in vitro and in vivo (Brinker F., A comparative review of eclectic female regulators. Brit J Phytother 1997; 4:125). Drs. Jones and Larson cite additional literature that points out that these same glycosides reduce coronary flow by 26% on average, leading to a negative inotropic effect in vitro.

While clinicians using herbal remedies should not employ blue cohosh prior to the ninth month of pregnancy due to its emmenagogue, abortifacient, and uterine stimulant effects (Brinker F., Herb Contraindications and Drug Interactions. Sandy, OR: Eclectic Institute, 1997: 26-7), several questions in this report remained unanswered. For example, why was the herb not analyzed with high-pressure liquid chromatography to ensure that what was consumed by the mother was actually blue cohosh and was not contaminated with some other herb that may cause cardiac complications? Furthermore, what was the actual dose of the herb per tablet, and was it an extract? Without these facts, it is difficult to assess how much of the herb was actually given and what constitutes a toxic dose. This case reinforces the position that medications of any sort should not be employed during pregnancy without a careful risk-to-benefit evaluation of the substance in question. Clinicians should have a detailed understanding of plant pharmacology and toxicology so that they can adequately counsel their pregnant patients and hence avoid potential complications. While the authors of this paper admit that the evidence they present relating infant cardiac injury to the maternal consumption of blue cohosh is circumstantial, it is clear that those who administer this herb should do so with greater caution.

Natural Product Research Consultants, Inc.

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By R. Reichert

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