Chorioamniotic membrane separation following fetal surgery

Objective: As the volume of fetal surgery cases has steadily increased, an increasing incidence of chorioamniotic membrane separation (CMS) has been noted. Due to the potential adverse consequences from this abnormality, we reviewed the last decade of experience with fetal intervention at our institution and examined the incidence and outcomes of fetuses given this diagnosis. Study Design: A retrospective chart review of 75 fetal surgery cases at our institution was performed. Variables analyzed included preoperative, operative, and outcome data. Postoperative ultrasounds were evaluated for the presence of CMS. Results: Excluding operative deaths, the incidence of CMS was 47%. There were significant differences (p < 0.05) in time to delivery (7 vs 5 weeks), cases using a perfusion pump (80% vs 60%), and number of trocars (2.13 vs 1.54) in cases of CMS versus those without. Ultrasounds showed normal to high levels of amniotic fluid in 97% of cases. There was an increased incidence of premature rupture of membranes (63% vs 45%), preterm labor (57% vs 38%), and chorioamnionitis (29% vs 15%) with CMS, but no difference in mortality rate. Conclusion: CMS is a frequent finding following fetal surgery. It is associated with significant morbidity but is manageable with close follow-up in a hospital setting. Following fetal surgery, the finding of CMS can be a life-threatening complication that warrants further study to understand its etiology and prevention.