Anatomy of the fetal membranes using optical coherence tomography: part 1

In vitro studies on the structure of human fetal membranes have involved light or electron microscopy with fixation, dehydration, and staining. Recently, optical coherence tomography (OCT), an imaging technology, has provided high-resolution cross-sectional images of living biological tissues, with a penetration of 2-3 mm. We evaluated the use of this technology to examine the histologic features of human fetal membranes immediately after delivery.

Samples of fetal membranes of ten patients undergoing cesarean deliveries (four uncomplicated pregnancies, four with preeclampsia, and two with chorioamnionitis) and eight patients undergoing vaginal deliveries (six uncomplicated pregnancies and two with chorioamnionitis) were collected immediately after delivery. Samples were stretched across customized disks, rinsed, and analyzed using a time-domain OCT imaging system. Following OCT scanning, the samples were placed in formalin for histologic study. The OCT images were compared to histologic images of common human fetal membrane features.

We were able to delineate the layers of the fetal membranes using bench-top time-domain OCT. The system was able to image histologic features of the fetal membranes, such as microscopic chorionic pseudocysts, ghost villi, meconium stained membranes, and chorioamnionitis. The OCT images corresponded with the histologic findings.

This feasibility study demonstrates the potential of OCT technology for real-time assessment of human fetal membranes and may provide clinically useful information at delivery.