Chorioamniotic Membrane Separation Found on Routine Testing in an Otherwise Asymptomatic Woman With Late Preterm Twin Gestation.

BACKGROUND: Chorioamniotic membrane separation (CMS) is a rare finding that is commonly preceded by invasive fetal procedures. The presence of CMS can also be associated with uncommon maternal or fetal conditions as well as preterm delivery, amniotic band syndrome, umbilical cord complications, and fetal and neonatal death. It is classified as a high-risk antepartum condition due to the significant fetal morbidity and mortality that may ensue.

CASE REPORT: A 40-year-old gravida 5 para 1212 at 35 weeks presented for antepartum fetal testing. Her antepartum course was complicated by di-di twin gestation, chronic hypertension, and advanced maternal age. A routine ultrasound (as part of the antepartum fetal testing) identified an incidental finding of CMS. The patient's only reported symptom was that of preterm contractions, without evidence of active labor, and other fetal testing was reassuring. She had a repeat cesarean section that day and the suspected etiology was preterm, premature rupture of membranes of Twin B that was seen on entry into the uterine cavity.

DISCUSSION: Chorioamniotic separation is a rare occurrence associated with significant adverse fetal outcomes. This is the first reported case of incidental diagnosis in a twin pregnancy during antepartum fetal surveillance testing. Our detection resulted in the delivery of late preterm, but otherwise healthy, twin neonates.