Gestational Maturation of Electrical Activity of the Stomach

Gestational maturation of gastrointestinalmotility is a key factor in readiness of the pretermneonates for enteral nutrition. Since gastric motilitymainly depends on the electrical activity of the smooth muscle cells, it was of interest to investigatethe developmental aspects of electrical activity of thestomach. The latter was recorded weekly throughcutaneous electrogastrography in 27 preterm infants (aged 29-34 weeks of gestation). Recordingswere done for 1 hr before and 1 hr after meal. Theelectrogastrographic variables measured were: percentageof normal gastric rhythm, i.e., 2-4 cpm; percentage of tachygastria (>4 cpm); the fed-to-fastingratio of the dominant electrogastrographic power; andthe instability coefficient of the dominant frequency.Data were compared with those measured in 10 full-term infants. Peaks of normal electricalactivity (2-4 cpm) were present in most of therecordings at all the gestational ages; however,percentages of both normal electrical rhythm andtachygastria in preterm infants were similar to thosemeasured in full-term infants (mean ± SD) (normalrhythm; 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). Thecoefficient of instability of the dominant frequency inpreterm infants was also similar to the value measuredin full-term infants by 35 weeks of gestation, whereasthe EGG power showed a significant increase in thepostprandial state at all the gestational ages. We conclude that a maturation pattern of theelectrical activity of the stomach can be detected bymeans of a noninvasive tool such as cutaneouselectrogastrography: a normal electrical rhythm can bedetected at very early gestational ages; however, thisactivity becomes dominant at around the 35 weeks ofgestational age. In preterm infants developmentalchanges of gastric electrical activity are a function of advancing postnatal age.