GASTROINTESTINAL AND PANCREATIC HORMONES IN THE HUMAN FETUS AND MOTHER AT 18-21 WEEKS OF GESTATION

Several gastrointestinal hormones appear to play an important developm ental role in the newborn, particularly in preterm neonates. Although the cells producing these peptides develop towards the end of the firs t trimester, fetal secretion of these regulatory peptides has not hith erto been demonstrated. Using samples collected by fetoscopy at 19-21 weeks of gestation we have measured concentrations of several gastroin testinal and pancreatic hormones. Maternal venous and amniotic fluid h ormone concentrations were measured simultaneously. Concentrations of the pancreatic hormones, insulin, glucagon and pancreatic polypeptide (PP) were similar in fetal and maternal blood. Gastrin and motilin wer e present in the fetal circulation but at about 30% (p < 0.05) and 60% (p < 0.01) of the maternal levels, respectively. In contrast, enterog lucagon concentrations were more than twofold higher in the fetal circ ulation compared with maternal levels (p < 0.05). Concentrations of ga stric inhibitory polypeptide (GIP) in fetal blood were higher than lev els in maternal blood but not significantly. Concentrations of GIP (p < 0.001) were higher in the amniotic fluid than the fetal circulation. Gastrin and glucagon levels were similar in amniotic fluid and fetal blood. In contrast, PP and motilin were present in amniotic fluid, but at lower concentrations than in fetal blood. Enteroglucagon was not d etectable in amniotic fluid. In conclusion, several alimentary hormone s are secreted in the fetus at midterm. Since these peptides have trop hic, secretory and motor effects on the gut, it is likely that these r egulatory peptides are involved in the functional development of the f etal intestine.