Comparison of Amnio‐Exchange With a Novel Synthetic Amniotic Fluid Versus Commercially Used Fluids for Fetal Therapy: An In Vivo Rodent Model

Abstract

ObjectiveNormal Saline (NS) and Lactated Ringer's (LR) damage human amniotic epithelium in vitro when compared with a synthetic amniotic fluid (Amnio‐well, AW). We sought to evaluate the effect of amnio‐exchange with NS, LR, and AW in vivo.MethodsOn day E17.5, pregnant rats underwent amnio‐exchange with NS, LR, or AW. Fetuses in each pregnant rat that did not undergo amnio‐exchange acted as controls. Amnions were harvested at E20.5 and ultrastructure evaluated via electron microscopy. Protein levels of cleaved matrix metalloproteinase 9 (MMP9) and collagen 1 (Col1a) were evaluated via Western Blot. Connexin‐43 expression was evaluated via immunofluorescence (IF).ResultsThere was an increase in amnion microfractures and epithelial cellular shrinkage with NS and LR compared with control and AW. The cleaved MMP9/Col1 ratio was increased 3.9‐fold in NS (p < 0.001) and 4.5‐fold LR (p = 0.0201) relative to control, whereas AW expression was similar to control (p = 0.636). Connexin‐43 was also increased on IF in NS and LR relative to AW (mean gray intensity 26.5 ± 4.5, 26.5 ± 6.7, 19.2 ± 3.4, p < 0.001).ConclusionAmnio‐exchange with NS and LR led to increased amniotic microfractures and collagen degradation compared with synthetic amniotic fluid. Larger models are warranted to validate or refute these findings.