Timeline of embryo resorption. Ultrasonographic markers of normal development are outlined on the x-axis. The boxes on the y-axis describe the different stages of resorption. The day of detection of the different resorption stages are given in brackets for each resorption site of this study (R1-R23). The day of collection of the resorption sites is indicated by the cross symbol. Observations of follow up exams are aligned by arrows. EPC – ectoplacental cone; *embryo under resorption located outside the embryonic cavity.