LAUSR

Abstract Objective To examine the changes in CRH concentrations in the blood serum of pregnant women and in the placenta of patients after the 41st week of gestation, and to determine its influence on the effectiveness of inducing labor and its progress. Materials and Methods The study group comprised pregnant patients who did not deliver until the 41 week of gestation (n = 114). The control group was divided into two subgroups: patients in whom delivery started spontaneously before the 41st week of gestation (n = 24) and pregnant patients in whom delivery started spontaneously after the 41st week of gestation (n = 23). Blood serum and placenta were obtained from the patients. Corticoliberin originating from blood serum was assessed with the use of ELISA Kit. Parts of the placenta were stained with monoclonal antibodies for the presence of corticoliberin, corticoliberin receptors 1 and 2. Results No statistically significant differences were found with regard to corticoliberin concentrations in the blood or during a qualitative assessment of the number of CRH R1 in the placenta between the research groups. However, corticoliberin receptor 2 had a statistically higher expression rate in the control group in which the delivery started spontaneously before the 41st week of gestation. Conclusion In post-term pregnancy, the up-regulation of CRH R2 receptor is disturbed with no change in CRH R1 expression, which complicates the initiation of labor despite correct corticoliberin levels in both blood serum and the placenta. Pregnancy duration over 41 weeks and the effectiveness of preinducing or inducing labor do not depend on corticoliberin concentrations.