Maternal and embryonal/fetal beta-endorphin concentrations during the first trimester of pregnancy

In this study, we have determined the beta-endorphin concentrations in the plasma of 11 cases during the first 3 months of pregnancy, as well as the corresponding products of conception, collected by hysterosuction, during the course of voluntary abortion. The purpose of this study is to compare the values obtained by the analysis of maternal plasma and the material collected by hysterosuction. The beta-endorphin concentrations were obtained by radioimmunologic methods using a kit which allows a separation from beta-lipotropin. The specimens obtained by hysterosuction (8 +/- 1.7 pmol/l) showed significantly higher levels of beta-endorphin than those observed in the maternal plasma (2.6 +/- 0.3 pmol/l). Thus, already in the earliest gestational period, the data are consistent with a feto-placental origin for this opioid peptide.