The stress hormone response to intrauterine transfusion Rh alloimmunized fetuses

Abstract

Objective To evaluate the effect of Rh alloimmunization and intrauterine transfusion on fetal stress hormone levels. Method Umbilical venous samples were obtained immediately prior to transfusion in 51 anemic fetuses and in a control group of 30 non-anemic fetuses. In 16 of the anemic fetuses a repeat sample was obtained post-transfusion. Samples were assessed for hematocrit, pH and levels of β-endorphin, cortisol and adrenocorticotropin. Results The mean initial hematocrit was significantly lower, while the median concentrations of β-endorphin and cortisol were higher in anemic compared with non-anemic fetuses at initial sampling. In contrast, fetal adrenocorticotropin levels did not differ between the groups. Among anemic fetuses, both serum β-endorphin and cortisol levels displayed a strong negative correlation with fetal hematocrit (r =- 0.46, p = 0.006 and r = - 0.54, p < 0.001, respectively). Among anemic fetuses sampled before and after transfusion, levels of β-endorphin were significantly lower, while cortisol levels were significantly higher post-transfusion. Maternal cortisol levels also increased post-transfusion. Conclusion Fetal anemia is associated with increased β-endorphin and cortisol levels. While intrauterine transfusion is associated with a decline in β-endorphin concentrations, fetal cortisol levels increase following transfusion, potentially reflecting transplacental passage of post-transfusion increases in maternal cortisol.