Twenty-two twin pregnancies each with one growth-retarded and one normal twin fetus were examined to determine the effects of fetal growth retardation on the maturation of the adrenal gland with respect to cortisol and dehydroepiandrosterone sulphate (DHEAS). The growth-retarded twin fetuses (IUGR) had lower umbilical arterial concentrations of DHEAS than their siblings (IUGR 5.25 ± 2.4; non-IUGR 6.51 ± 2.9 μmol/l; p < 0.01), whereas cortisol concentrations were not statistically different (no labor, IUGR 1,134 ± 751, non-IUGR 1,140 ± 958 μmol/l; labor IUGR 2,062 ± 929, non-IUGR 1,609 ± 469 μmol/l). These data suggest that while the definitive zone of the fetal adrenal is as well-developed as in non-growth-retarded twins, the fetal zone shows reduced secretory capacity of Δ5-steroids. This supports the hypothesis that in growth retardation the adrenal gland shows features of increased maturation.
