Gestational maturation of electrical activity of the stomach.

Gestational maturation of gastrointestinal motility is a key factor in readiness of the preterm neonates for enteral nutrition. Since gastric motility mainly depends on the electrical activity of the smooth muscle cells, it was of interest to investigate the developmental aspects of electrical activity of the stomach. The latter was recorded weekly through cutaneous electrogastrography in 27 preterm infants (aged 29-34 weeks of gestation). Recordings were done for 1 hr before and 1 hr after meal. The electrogastrographic variables measured were: percentage of normal gastric rhythm, ie, 2-4 cpm; percentage of tachygastria (>4 cpm); the fed-to-fasting ratio of the dominant electrogastrographic power; and the instability coefficient of the dominant frequency. Data were compared with those measured in 10 full-term infants. Peaks of normal electrical activity (2-4 cpm) were present in most of the recordings at all the gestational ages; however, percentages of both normal electrical rhythm and tachygastria in preterm infants were similar to those measured in full-term infants (mean +/- SD) (normal rhythm; fasting: 70.2 +/- 3.8, fed: 72.2 +/- 5.0; tachygastria: fasting: 24.6 +/- 4.0, fed: 19.1 +/- 3.5) by 35 weeks of gestation (normal rhythm; fasting: 67.5 +/- 2.0, fed: 69.6 +/- 4.4; tachygastria: fasting: 27.1 +/- 4.0, fed: 25.6 +/- 4.1). The coefficient of instability of the dominant frequency in preterm infants was also similar to the value measured in full-term infants by 35 weeks of gestation, whereas the EGG power showed a significant increase in the postprandial state at all the gestational ages. We conclude that a maturation pattern of the electrical activity of the stomach can be detected by means of a noninvasive tool such as cutaneous electrogastrography: a normal electrical rhythm can be detected at very early gestational ages; however, this activity becomes dominant at around the 35 weeks of gestational age. In preterm infants developmental changes of gastric electrical activity are a function of advancing postnatal age.