Heartburn in Late Pregnancy. Manometric Studies of Esophageal Motor Function*

Heartburn is a burning, often hot sensation which may localize in the throat or substernal region.It is especially common during pregnancy.Gastroesophageal reflux and neuromuscular dys- function of the esophagus have been suggested as underlying pathophysiological mechanisms, but contradictory evidence has prevented a clear definition of the cause of heartburn.A prospective clinical study of 560 pregnant women disclosed that 50 per cent developed heart- burn which invariably disappeared after delivery (1).The self-limited character of pregnancy makes it an ideal experimental period during which to study heartburn.Transducer pressure recordings of esophageal motility are well adapted to such a study.This paper reports the results of serial esophageal motility studies in pregnant women with and without heartburn and in a group of asymptomatic normal women of similar age. METHODSSubjects.Fifty-seven esophageal motility studies were performed on 20 pregnant women who complained of heartburn during pregnancy.The 8 primiparae and 12 multiparae ranged in age from 16 to 39 years, with an average age of 28.Similarly, 63 recordings were ob- tained from 19 pregnant women who never developed heartburn throughout pregnancy; in this group were 10 primiparae and 9 multiparae, 20 to 35 years old, with an average age of 26.Each women was studied at least once during and after pregnancy, but the total number of studies in each subj ect depended on the month of pregnancy when the patient was first seen.Fourteen asymptomatic normal nonpregnant women, 22 to 44 years old, with an average age of 26, served as controls; each subject was studied 6 times at monthly intervals.Technique.The technique of recording esophageal motility utilizes 3 polyethylene catheters, each with an internal diameter of 1.5 mm, which are fastened together and sealed at the tips.A single lateral opening in each * Supported in part by United States Public Health Service Grants C2578, A1785, and A3473 and the Nor- wich Chapter of the Connecticut Heart Association. 955.2Q, 0.).1.* No diffuse spasm or secondary peristalsis occurred in any of the control subjects.