To compare the distribution of proopiomelanocortin (POMC) in decidua and placenta samples from missed abortion and voluntary termination cases in order to research the effects in the etiology of missed abortion.Decidual materials were collected from patients who were diagnosed with missed abortion (n=19) and legal voluntary termination cases (n=15) under 10 gestational weeks. Materials were divided into 2 groups for examination. For all samples, POMC primary antibody was performed by immunohistochemical staining. The number of stained cells was calculated by using the H-score technique.In the missed abortion group the mean age was 28.7 (18–41), and in the control group the mean age was 27.5 (21–37). POMC immunoreactivity was determined to be lower in the parenchyma and placenta of the missed abortion group than those of the control group. POMC immunoreactivities were found to be higher in both the syncytiotrophoblast and cytotrophoblast cells of the missed abortion group than those of the control group (p<0.005).POMC has become a paradigmatic polypeptide precursor and has a role in the parturition process. Local production of POMC in placenta and decidua may influence pregnancy and may have a role in missed abortion pathogenesis.