Changes in postprandial release patterns of gastrointestinal hormones in late pregnancy and the early postpartum period.

Intestinal transit time increases and gastrointestinal incretin effect is reported to decrease in pregnancy. The release patterns of gastrointestinal hormones related to these functions were studied in eight women before and after ingestion of a standardized meal at 32-34 weeks gestation and at 4 days postpartum. Basal plasma motilin and the integrated meal response of motilin, pancreatic polypeptide (PP) and gastric inhibitory polypeptide (GIP) were significantly lower in pregnancy than postpartum. The meal-induced rise of somatostatin and vasoactive intestinal polypeptide (VIP) was, however, absent in late pregnancy; whereas the somatostatin response recovered postpartum, and the plasma VIP concentrations stabilized at significantly higher levels postpartum without any meal response. Basal and meal-induced plasma insulin were significantly higher in pregnancy.