Late-onset spontaneous chorioamniotic membrane separation mimicking amniotic band sequence with rapid progression to preterm premature rupture of membranes
Year: 2026
Type: article
Study design: Case Report
Abstract: Objectives: Spontaneous chorioamniotic membrane separation (CMS) diagnosed in the third trimester is rare, and its short-term clinical course remains poorly characterized. We report a case of late-onset CMS with rapid progression to preterm premature rupture of membranes (PPROM). Case presentation: A 23-year-old woman with a prior cesarean delivery was referred at 35 weeks for suspected fetal macrosomia. At 36+4 weeks, ultrasonography revealed freely mobile, multilayered membranes adjacent to the fetal extremities and umbilical cord, raising concern for amniotic band sequence. Detailed anatomical assessment and color Doppler evaluation demonstrated intact extremities and preserved distal perfusion, supporting a diagnosis of CMS. The patient was admitted for surveillance, and PPROM occurred within hours of diagnosis. Cesarean delivery resulted in a live male infant weighing 4,170 g (Apgar scores 8/9). Intraoperative findings confirmed near-complete amnion-chorion separation. Conclusions: Late-onset spontaneous CMS may mimic amniotic band sequence and can progress rapidly to membrane rupture. Careful sonographic differentiation is essential. Given the potential for rapid clinical deterioration, close surveillance may be warranted, particularly in late gestation.
Institutions: Balıkesir Atatürk City Hospital, İzmir Şehir Hastanesi
Language: English
Subfield: Obstetrics and Gynecology
Field: Medicine
Domain: Health Sciences
Open Access status: gold
Estimated APC paid: $565
OpenAlex ID: W7223250288
