Serum total estriol in abnormal newborn infants

Abstract

Serum total estriol was determined in blood samples obtained from 128 newborn infants admitted to a newborn intensive care unit. Forty of the infants were studied by serial sampling. The estriol was assayed following hot acid hydrolysis of the serum, using a highly specific antibody to estriol. The mean values of serum total estriol, on the first day of life, ranged from 959 ± 413 (S.D.) ng/ml in infants <30 wks gestation to 1127 ± 489 (S.D.) ng/ml in infants 33–35 wk gestation. Mean values fell rapidly postnatally, to 151 ± 131 (S.D.) ng/ml in 11–25 day infants, and 39 ± 20 (S.D.) ng/ml in infants 35–73 days of age. There were no significant differences between total estriol values, on the first day of life, of infants with and without hyaline membrane disease. The t 1 2 of the endogenous total estriol could be determined in 21 infants. The t 1 2 s tended to be less with increasing gestational age, the regression equation being y = 5.98 − 0.128 × ( r = −0.51). Intrauterine growth retarded and dysmature infants > 35 wk gestation had a mean serum total estriol level of 950 ± 477 (S.D.) ng/ml on the first day of life. This value is similar to the mean of the appropriate for gestational age infants > 35 wk, 1028 ± 440 (S.D.) ng/ml. Very slow declines in serum total estriol were found in 4 infants with intestinal hypomotility who developed necrotizing enterocolitis. The cause may be enterohepatic shunting of estriol as a result of the delay in clearing meconium from the intestinal tract.