Fetal growth in relation to histamine concentration in urine.

Abstract

SummaryThe excretion of free histamine in urine was determined in 225 normal pregnancies. It rose to a plateau at about 160 μg./24 hours in the third trimester of pregnancy and then rapidly fell to below 100 μg./24 hours at term. The rate of excretion was found to be helpful in the assessment of fetal lung maturation in late pregnancy. When the excretion rate exceeded 100 μg./24 hours the fetus was likely to be immature, growing adequately and standing a chance of developing hyaline membrane disease if delivered at this stage. When persistently low rates of histamine excretion were recorded, the fetus had either reached the stage of normal full term development or was growth retarded. In either case the lungs of such a fetus were likely to be mature.