Abstract: Objective：To investigate the clinical characteristics of the chorioamniotic membrane separation （CMS） after
invasive intrauterine treatment. Methods：Retrospective review of a maternal population undergoing intra uterine therapy at a single center following the postoperative ultrasound to follow-up for membrane separation. The intrauterine procedures consisted of cord coagulation reduction，amnioreduction，intrauterine transfusion in Center of Fetal，the First Affiliated Hospital of Sun Yat-sen University from 2001 July to 2010 June. Results：From 2001 to 2010，we found 9 cases of CMS in 269 cases after invasive procedure. 4 cases（4/213，1.88%） had amnioreduction，1 case（1/28，3.6%） had intrauterine transfusion and 4 cases（4/28，14.3%）had cord coagulation reduction. Conclusions：There was a higher risk of CMS after fetoscopic cord coagulation reduction.

Key words: Chorion, Amnion, Ultrasonography, Therapy, Diagnosis