It is generally believed that pregnancy predisposes to disease of the biliary tract. In previous papers one of us1 was concerned in reports of relief of biliary pain following cholecystectomy. Pain seemed to be due to an increased pressure in the bile ducts resulting from an obstruction at the lower end of the common bile duct due to a muscle spasm. This spasm seemed to be in the muscle in the second portion of the duodenal wall. This spasm and the resulting pressure and pain were relieved by the use of amyl nitrite and glyceryl trinitrate.
Recently in a case of intractable vomiting of pregnancy in which jaundice had begun to develop, it seemed possible that such a spasm might be a causative factor. Glyceryl trinitrate was given after each meal with the result that vomiting stopped and a proposed therapeutic abortion was rendered unnecessary. This experience suggested the
McGOWAN JM, BAKER JO, TORRIE AM, LEES J. VOMITING OF PREGNANCYA PART OF THE MECHANISM OF PRODUCTION AND A METHOD FOR ITS RELIEF. JAMA. 1938;110(7):498–500. doi:10.1001/jama.1938.02790070022006