Postnatal development of liver and exocrine pancreas in polycythemic newborn infants

In 35 newborn infants appropriate for gestational age the influence of neonatal polycythemia (venous hematocrit greater than 60% measured between the second and fourth hour of life) on development of enterohepatic circulation of bile acids, activities of pancreatic enzymes in duodenal juice, and the effects of hemodilution were studied during the second week of life. A significant correlation was found between the initial hematocrit and both the bile acid concentration in serum and lipase and trypsin activity in duodenal juice. Of 35 infants, 10 were not treated with hemodilution due to asymptomatic polycythemia; they had the highest concentration of serum bile acids associated with the lowest lipase and trypsin activity in duodenal juice. However, the 25 infants treated with hemodilution also showed serum bile acid concentrations and lipase and trypsin activity in duodenal juice out of the normal range when compared to normocythemic infants. These data indicate that, during the first days of life, polycythemia results in a delayed postnatal development of enterohepatic circulation of bile acids and exocrine pancreas functions independently from the occurrence of clinical symptoms. Thus, it can be concluded that, on the first day of life, all polycythemic infants should be treated with hemodilution. Moreover, the nutritional management of these infants must also account for the limited functional capacity of the gastrointestinal tract.