Optimal temperature for the measurement of transcutaneous carbon dioxide tension in the neonate.

Abstract

cemic for the first 72 hours. In hypocalcemic IDM, serum PTH concentrations did not rise in response to the low serum calcium concentration. In normocalcemic IDM, in association with a small fall in the iCa concentrations after birth, serum PTH concentrations rose significantly, a finding similar to that reported for term well infants? In this study, even though hypocalcemic IDM were less mature, the sluggish response of serum PTH appeared to be inappropriately low for gestational age, as assessed by covariance analysis. Thus, maternal diabetes may be an independent factor related to suppressed neonatal parathyroid function in addition to the possible effects of prematurity. The lack of increase of serum PTH concentrations in hypocalcemic IDM theoretically may be due to increased catabolism of circulating PTH by the kidney, liver, or bone. No data are available at present regarding catabolism of PTH in the neonatal period. Alternatively, parathyroid function may be suppressed by high intrauterine calcium concentrations in utero. Although serum ionized Ca concentrations in the umbilical vein were high, and appeared higher in hypocalcemic infants when compared with those in normocalcemic infants, there actually was no significant difference between the groups; further study will be needed to test this possibility. Serum Mg concentrations were lower in hypocalcemic [DM compared with those in normocalcemic IDM, at 48 and 72 hours of age. In a previous study we demonstrated that maternal diabetes was associated with a significant incidence of hypomagnesemia in the infants and that neonatal hypomagnesemia was correlated with the severity of maternal diabetes and with maternal hypomagnesemia. 7 Since diabetes mellitus is associated With significant magnesium loss in the urine, and magnesium depletion, s it is possible that diabetes during pregnancy is indeed associated with magnesium deficiency. Magnesium deficiency is a well-known cause of decreased parathyroid hormone secretion? Thus we speculate that hypocalcemia in IDM is related to decreased parathyroid function, possibly related to maternal and fetal magnesium deficiency.