Stress mediators in the amniotic compartment in relation to the degree of fetal distress.

In an attempt to locate biochemical markers specific for fetal distress we measured the amniotic concentrations of beta-endorphin, ACTH, cortisol, dopamine, norepinephrine and epinephrine with its major metabolite metanephrine (MN) in pregnancies with documented fetal well-being and pregnancies complicated by hypertension and fetal distress. While higher levels of cortisol and MN were found only in a selected subgroup of highly compromised subjects (p < 0.001 and p < 0.005, respectively), beta-endorphin increased significantly under conditions of moderate or severe intrauterine sufferance (p < 0.001 in both cases). Due to higher levels of the opioid even during the initial stage of fetal discomfort we evaluated its characteristics as a possible clinical marker. Specificity was 88.5%, whereas the sensitivity of 65.6% in the moderately compromised subgroup increased to 88.9% in severely suffering fetuses. Although more accurate and mainly real-time information on the fetal health status is obtained by means of biophysical methods, the determination of amniotic fluid beta-endorphin might be of clinical usefulness in prenatal diagnosis.