Alterations in fetal metabolism subsequent to maternal morphine administration

Umbilical blood flow and fetal oxygen, glucose, lactate, and pyruvate uptakes were measured in the chronically catheterized fetal lamb subsequent to administration of morphine sulfate to the mother (0.66 mg/kg). No significant change in umbilical blood flow or fetal oxygen consumption was noted during the 120-minute observation period. Although transient maternal hyperglycemia was noted, during the 120-minute observation period. Although transient maternal hyperglycemia was noted, there was no significant alteration in fetal arterial glucose concentrations. Umbilical vein glucose levels, however, were significantly below control values at 45 minutes (-21%) and 60 minutes (-18%). As a result, fetal glucose uptake was markedly reduced at 45 minutes (p less than 0.05). No major alterations were demonstrated in fetal uptake of lactate or pyruvate. These data demonstrate that the administration of morphine to the mother alters fetal glucose homeostasis, and that this alteration may be a result of decreased permeability of the placenta to glucose.