TEMPORAL CHANGES IN GASTRIC VOLUME IN THE HUMAN FETUS IN LATE PREGNANCY

Disturbed fetal gastrointestinal tract function is associated with hyd ramnios and may be a marker of later gastrointestinal disease. We inve stigated gastric motor function in the human fetus to establish the ra nge and rate of fluctuation of gastric volume. Two pairs of orthogonal gastric diameters were measured at 5-min intervals for 1-h periods us ing a linear-array ultrasound scanner in 12 fetuses in late pregnancy (26-40, median 35.5 weeks gestation). A gastric volume index (GVI) was calculated. Maximum absolute gastric volume index correlated signific antly with gestational age. The minimum gastric volume index as a perc entage of the maximum (0.60.4%, median 28.1%) showed that marked chang es in gastric dimensions occur. Filling (41.5-74.1, median 62.6-degree s) and emptying (46.6-80.9, median 61.70) angles were calculated for t he longest continuous Filling and emptying periods using a linear mode l, and showed no difference in the rates of filling and emptying. Peak -to-peak and trough-to-trough durations suggested a periodicity of 35- 55 min. Investigation of the development of normal fetal gastric motor activity may lead to a better understanding of postnatal adjustment t o enteral feeding, and may provide a diagnostic method for antenatal d iagnosis of gastrointestinal functional disturbances.