Dexamethasone levels in treated pregnant women and newborn infants.
Dexamethasone concentration was measured in plasma and amniotic fluid by radioimmunoassay using a rabbit antiserum raised against DX-hemisuccinate-albumin. Recoveries of added tracers averaged 70% after paper chromatography. The within- and between-assay coefficients of variation averaged 10%. The lower limit of detection was 0.2 mug/dl when 0.4 ml of plasma was assayed. Ten healthy pregnant women at term had cesarean sections 8 to 11 hours following administration of 8 mg of DX orally. DX levels in maternal vein, in umbilical vein and artery, and in amniotic fluid averaged 2.2, 2.9, 2.6, and 2.5 mug/dl, respectively. Although cortisol levels were markedly suppressed, the total relative glucocorticoid activity in blood of fetuses treated with DX far exceeded that of the untreated group.
D000653:Amniotic Fluid / Q000378:metabolism; D003907:Dexamethasone / Q000097:blood / Q000378:metabolism* / Q000627:therapeutic use; D005260:Female; D006801:Humans; D006854:Hydrocortisone / Q000097:blood / Q000378:metabolism; D007231:Infant, Newborn; D008297:Male; D008431:Maternal-Fetal Exchange; D011247:Pregnancy; D011863:Radioimmunoassay; D012127:Respiratory Distress Syndrome, Newborn / Q000517:prevention & control; D014469:Umbilical Arteries; D014471:Umbilical Veins
D003907:Dexamethasone; D006854:Hydrocortisone