(A) Viable embryos per mouse among UP (n = 18), IP (n = 15), IP LMWH-treated (n = 11), and IP enoxaparin-treated mice (n = 5) on ED 12. Bars represent the mean. (B) Mean (± SEM) viable embryos as a proportion of total embryos within each group as described in panel A. *P<0.0001, **P = 0.0008, ***P = 0.0270. (C) Gross pathological view of UP uterus. (D) Gross pathological view of IP uterus, showing active embryonic expulsion (arrow), diminished vascularization (black blunt arrow), and intrauterine hemorrhage (white blunt arrow). (E) Gross pathological view of LMWH-treated IP uterus with one resorption (arrow). (F, I) Hematoxylin and eosin (H&E)-stained thin section of a UP conceptus. (G, J) H&E-stained thin section of an IP conceptus; arrow indicates fibrin deposition. (H, K) H&E-stained thin section of an IP LMWH-treated conceptus. Enlargements (panels I, J and K) delineate the three principle regions of the murine placenta, decidua (d), junctional zone (j), labyrinth (l), and also identify the embryo (e). Gross macroscopic pictures were taken with a Kodak Easyshare DX7630 digital camera at 6 MP. Micrographs were captured on an Olympus BX41TF light microscope using an Olympus D70 digital camera. Panels F, G, and H depict magnification with a 2× objective and panels I, J, and K with a 4× objective. Images were resized, cropped as appropriate, and in some cases brightened using GNU Image Manipulation Program v2.6.