Teratogen update: ergot and ergotamine.

Ergotamine is a purified ergot alkaloid that has been suspected of being teratogenic. Animal data have shown effects mainly at doses toxic to the mother. Clinical reports in humans have been anecdotal, but in many the malformations are consistent with vascular injury. However, epidemiologic studies have not shown any clear increase in malformations among exposed infants. This may reflect the limited exposure and toxicity when used episodically. Ergot toxicity which can result in severe vasospasm does not spare the fetus or mother and ergotamine should not be considered without risk. Ergotamine should be avoided in pregnancy, and the counselling of the woman with an exposed fetus should focus on possible toxic exposure.