The aim of the present investigation was to study volume, pH and the levels of gastrin- and somatostatin-like immunoreactivity in gastric aspirates obtained immediately after birth from 25 healthy infants. In addition, the same parameters were measured in amniotic fluid collected from 11 of the mothers. The median volume of the gastric contents was 4 ml (range 0-11) and median pH was 6.96 (range 2.77-9.58). Gastrin and somatostatin median concentrations were 8 pM (range 0-52) and 67 pM (range 15- greater than 1,000), respectively. The corresponding levels in amniotic fluid were 8.2 +/- 3.6 pM and 28.4 +/- 5.3 pM, median pH was 9.22 (range 8.05-9.58). There was a significant correlation between volume and pH of gastric contents. The pH of the gastric aspirate was inversely correlated with the somatostatin levels. No correlation could be demonstrated as regards levels in amniotic fluid and gastric content. Gastric content and amniotic fluid were not correlated regarding pH, gastrin and somatostatin. It is suggested that the foetus drinks about 10 ml portions of amniotic fluid which are gradually emptied from the stomach and that these drinking episodes are associated with gastric exocrine and endocrine secretion normally seen following feeding after birth.