Analysis of TFPI^–/– embryos and placentas. (A) We observed 4 TFPI^+/– embryos (nos. 1-4) and 4 TFPI^–/– embryos (nos. 5-8) at E14.5 from the same litter in a cross between TFPI^+/– mice. Embryos 1 to 7 were alive and embryo 8 was dead. Hemorrhages were observed on the surface of placentas no. 6 and no. 7 (arrows) and placenta no. 8 was white. (B) Two E15.5 embryos. The TFPI^+/–/mTF^+/–/hTF^+/o embryo and placenta was normal, whereas the TFPI^–/–/mTF^+/–/hTF^+/o embryo was growth-retarded with signs of hemorrhage (arrow) and had a white placenta. The lower leg and/or tail were removed for genotyping (dashed line).