Various embryonic abnormalities at different stages due to LPA₄ deficiency. Mouse embryos at different developmental stages (E10.5, A-B; E14.5, C-E; E18.5, F-J) were macroscopically observed. Whereas many LPA₄-deficient embryos appeared normal, like WT embryos (A,C,F), some mutant embryos had phenotypic abnormalities as follows: effusions in the pericardial space (arrow) at E10.5 (B), severe edema (arrowhead) (D), fragile embryo (E) at E14.5, subcutaneous hemorrhage (h) (G-H), edema (H), retained placenta (I), and macerated embryo (J) at E18.5. In panels G and H, embryos have placentas (p). Scale bars, 1 mm in panels A-B; 10 mm in panels C-J.