PROGESTERONE AND ESTROGEN ARE POTENTIAL MEDIATORS OF GASTRIC SLOW-WAVE DYSRHYTHMIAS IN NAUSEA OF PREGNANCY

Women in pregnancy experience nausea, which correlates with gastric sl ow-wave rhythm disruption. Mediators of these dysrhythmias were explor ed. To quantitate slow-wave disruption, eight pregnant women with firs t-trimester nausea underwent electrogastrography after a 250-kcal meal . Results were compared with nonpregnant women with nausea during a pr ior pregnancy who received estradiol and/or progesterone to levels of the first trimester of pregnancy. Five pregnant women exhibited dysrhy thmias, with increases in combined recording time in tachygastria plus bradygastria, as well as decreases in the percentage of electrogastro graphy signal power in the normal 3 cycle/min range (cpm), compared wi th nonpregnant women (P < 0.05). Estradiol did not evoke dysrhythmias in nonpregnant women; however, progesterone induced increases in recor ding time in bradygastria plus tachygastria and increases in bradygast ric signal power with corresponding decreases in signal power in the 3 -cpm range (P < 0.05). With estradiol and progesterone coadministratio n, an additive effect was observed at 3.3 +/- 0.8 h, with increased re cording time in bradygastria alone and in bradygastria plus tachygastr ia with corresponding increases in bradygastric signal power and decre ases in power in the 3-cpm range (P < 0.05). In conclusion, women with nausea of pregnancy exhibit slow-wave rhythm disruption. Similar dysr hythmias are evoked in nonpregnant women by progesterone alone or in c ombination with estradiol in doses that reproduce levels in pregnancy. Thus gastric dysrhythmias in pregnancy may be due to a combination of elevated progesterone and estrogen levels.