in breast fed infants of diabetic mothers . Beta glucuronidase and hyperbilirubinaemia

A prospective study was performed comparing bilirubin concentrations in 10 breast fed term infants of diabetic mothers (IDM) to those of 10 breast fed normal term infants. The ,-glucuronidase concentrations in serum and breast milk were assayed in the respective mothers. Significantly higher bilirubin concentrations were noted in the IDM group. Serum and breast milk P-glucuronidase concentrations were significantly higher in diabetic mothers as compared with those of nondiabetic mothers. We suggest that the high concentration of ,-glucuronidase in breast milk of diabetic mothers is an additional important cause leadingto hyperbilirubinaemia in their breast fed infants. Hyperbilirubinaemia is observed more frequently in infants of diabetic mothers (IDM) than those of non-diabetic mothers. Although a number of hypotheses have been suggested, the pathogenesis remains uncertain.' To our knowledge, there are no previous reports describing the relationship between breast feeding and hyperbilirubinaemia in IDM. Neonatal intestinal ,B-glucuronidase antagonises the net clearance of bilirubin by increasing enterohepatic circulation causing increased serum bilirubin.2 In 1986, Gourley and Arend reported that the ,3-glucuronidase present in maternal milk is an important factor in breast milk jaundice.3 In a previous report higher values of serum ,-glucuronidase were found in pregnant diabetic women in comparison with non-diabetic women.4 In the present study we have examined the hypothesis that the increased concentration of breast milk j3-glucuronidase in diabetic mothers may be an additional cause of hyperbilirubinaemia in their breast fed infants. orally or intravenously were not included in the study. On the third postpartum day maternal serum and breast milk were collected and analysed for ,-glucuronidase. Breast milk was collected with a manual pump and immediately deposited in an iced container. All serum and breast milk samples were kept at -20°C and thawed at room temperature before assaying. The j3-glucuronidase activity was assayed with phenolphthalein mono-,-glucuronic acid substrate (Sigma kit No 325) and was expressed in Sigma units at 56°C. On the third day of life bilirubin was measured in the serum of all babies studied. This was done spectrophotometrically by the Advanced Bilirubin Stat-Analyzer Photometer model BR2. Statistical analysis was performed using Student's t test.