Objective      To study the expression of syncytin and glial cells missing (GCMa) in idiopathic fetal growth restriction (IFGR) placenta.       Methods      Thirty-two pregnant women who underwent cesarean delivery due to IFGR placenta served as an experimental group and 30 normal full-term pregnant women who underwent cesarean delivery due to social factors served as a control group in this study. Expressions of syncytin and GCMa in IFGR placenta tissue samples from two groups were detected by immunohistochemistry (IHC) and RT-PCR

respectively.       Results      IHC and RT-PCR showed that the expression levels of syncytin and GCMa were significantly lower in experimental group than in control group (P0.01). The low expression levels of syncytin and GCMa in experimental group were positively correlated with each other（r=0.537，P0.05）.       Conclusion      The syncytin and GCMa expressions are down-regulated in IFGR placenta tissue

indicating that they play an important role in the occurrence and progress of IFGR placenta.