No abstract

We assessed the relationship between neonatal hypoglycemia and newborn iron status in 15 hypoglycemic, large-for-date newborn infants, 12 of whom were infants of diabetic mothers. These infants had significantly lower mean serum iron concentrations, ferritin concentrations, percent iron-binding saturation and calculated iron stores, and significantly higher mean transferrin concentrations, total iron-binding capacity concentrations and mid-arm circumference:head circumference ratios when compared with either 15 euglycemic large-for-date or 15 euglycemic appropriate-for-date control infants (p less than 0.001 for all comparisons). All hypoglycemic infants had ferritin concentrations below the 5th percentile as compared to 3% of controls (p less than 0.001), and 67% had transferrin concentrations above the 95th percentile (controls: 0%; p less than 0.001). Only the hypoglycemic infants demonstrated a significant negative linear correlation between ferritin and transferrin concentrations (r = -0.83; p less than 0.001). Decreased serum iron concentrations were associated with size at birth (r = -0.60; p = 0.01) and with increased red cell iron (r = -0.60; p = 0.01), implying a redistribution of iron dependent on the degree of fetal hyperglycemia and hyperinsulinemia. Infants with increased red cell iron had more profound neonatal hypoglycemia. These results show a significant association between decreased iron stores and neonatal hypoglycemia in macrosomic newborn infants associated with a significant shift of iron into red blood cells.

In order to study the usefulness of upper mid-arm circumference (MAC) and mid-arm circumference:head circumference ratio (MAC:HC) measurements in assessing longitudinal growth in hospitalized preterm infants, we prospectively measured weights, lengths, occipitofrontal head circumferences (OFC), MACs, MAC:HCs, weight/length for age, nutritional intakes, and serum transthyretin and albumin levels in 50 preterm, low-birth-weight, appropriate for gestational age newborn infants during their first 4 postnatal weeks and at hospital discharge. At some time during hospitalization, weight measurements were abnormal (greater than or equal to 2SD from the gestational age mean) in 48% of the infants as compared with 24% with abnormal MAC measurements (p = 0.002). Abnormal MAC:HCs occurred in 25% of the infants as compared with 68% with abnormal weight/length for age values (p less than 0.001). During weeks 2-4, when nutritional intakes were adequate and serum transthyretin and albumin levels were normal, mean weight gain velocity was less than intrauterine rates and was significantly slower than MAC velocities, which were at or greater than intrauterine rates (p less than 0.001). At discharge, when all infants were gaining weight at intrauterine rates, weight measurements were still abnormal in 28% of the infants as compared with 10% of infants who had abnormal MACs (p = 0.005). Similarly, only 12% of infants had abnormal MAC:HCs as compared with 25% of infants with abnormal weight/length for age values at discharge (p = 0.05). The MAC and MAC:HC are useful for assessing longitudinal growth in preterm infants since they do not overestimate the prevalence of malnourishment during periods of apparent protein-calorie sufficiency.

Necrotising enterocolitis is the most common severe acquired gastrointestinal disorder in the neonate yet there remains disagreement on predictive and prognostic factors. A previously published risk score purports to predict infants at greater risk of the disease. Fifty-nine cases and 59 matched controls were evaluated using data from the first 24 h after birth to determine the predictive and prognostic value of the score for necrotising enterocolitis. In simple models the risk score was significantly, but inversely, associated with necrotising enterocolitis, primarily due to greater respiratory problems among controls. This finding contrary to the premise is clarified by a significant interaction of the risk score with feeding variables. Odds ratios for the risk score varied at different levels of daily feeding increments. However, the risk score was not statistically significant in any models which controlled for feeding increment and the interaction. The risk score was significantly associated with mortality among necrotising enterocolitis cases. Though the score was not statistically significant when the outcome was disease stage or surgery, trends were in the expected direction. The data suggest that the risk score itself may not be an independent predictor of necrotising enterocolitis, but may indicate infants more vulnerable to other potential risk factors and, in addition, may be related to prognosis for those who do develop necrotising enterocolitis.