Reduced cortisol concentrations in the cord blood of newborns whose mothers smoked during pregnancy. † 1089

Smoking (SM) during pregnancy has been associated with many undesirable effects on the fetus and child. Because maternal SM causes elevation of the stress hormones GH and PRL, in the newborns (NB), we measured cortisol (C) in NB of SM mothers. C was determined in the cord blood (CB) of 50 term NB whose mothers smoked ≥5 cig./day and 50 term NB of nonsmoking (NSM) parents. The C in the NB of the SM and the NSM mothers was 19.0±10.8 and 25.8±15.5 ng/ml, respectively (U=815, p=0.05). A singificant negative correlation was found between the no. of cig./ day and the C(r=-0.218,p<0.05). In 9 NSM mothers the serum C was 38.2±17.6, whereas in the CB and the venus blood of their NB on the 1^st, 2^nd, and 3^rd day, it was 31.6±10.2, 9.0±5.7, 6.9±3.0 and 9.1±5.3, respectively. In 11 SM mothers the C was 33.0±17.6, and in their NB it was 16.4±10.7, 10.2±10.1, 8.0±4.6 and 11.3±5.0, respectively. The Kruskal-Wallis test showed a significant difference of the C concentrations during the first 3 days of life between the NB of the SM and the NSM mothers (p<0.000). A significant difference between the two groups of NB was found only in the CB(p=0.006), but not in the venus blood during the following 3 days. A significant positive correlation was found between C and a-fetoprotein(p=0.05), but not between C and erythropoietin. It is suggested that the tobacco smoke causes neuroendocrine dysfunction in the fetus. The absence of a correlation between C and erythropoietin makes unlikely the possibility that the reduced C levels are due to an exhaustion of the fetal adrenal glands because of a hypoxia induced chronic fetal stress. The question of a decreased permeability of the maternal C through the placentae of the SM mothers remains unanswered.