Gastric dysrhythmias have been recorded from patients with a variety of
nausea syndromes. The aim of this study was to measure gastric myoelectric activity in women with and without
nausea during the first trimester of pregnancy. In 32 pregnant women gastric myoeletric activity was recorded for 30-45 min with cutaneous
electrodes that yielded electrogastrograms (EGGs). Frequencies of the EGG waves were analyzed visually and by computer. Subjects rated their
nausea at the time of EGG recording on a visual analog scale with 0 representing no
nausea and 300 mm severe
nausea. Gastric dysrhythmias were found in 26 pregnant subject: Seventeen had tachygastrias (EGG frequencies of 4-9 cpm), five had 1- to
2-cpm EGG waves, and four had flat-line patterns Mean
nausea scores of the subjects with tachygastrias, 1- to
2-cpm, and flat-line patterns were 64.8 +/- 13, 93.4 +/- 23, and 77.2 +/- 36, respectively. Six pregnant subjects had normal 3-cpm EGG patterns, and their
nausea scores averaged 2.8 +/- 1.1 (P less than 0.05 compared with
nausea scores in subjects with tachygastrias, 1- to 2-cpm, and flat-line rhythms). Six subjects with gastric dysrhythmias during pregnancy were restudied after delivery; each of these subjects had normal 3-cpm EGG patterns and none had
nausea. Thus, gastric dysrhythmias are objective pathophysiologic events associated with symptoms of
nausea reported during the first trimester of pregnancy.