Figure 7. Double decidual sac sign. US image of an early IUP demonstrates two hyperechoic rings (arrows). The inner ring represents the combined chorion-decidua capsularis, and the outer ring represents the decidua parietalis.
Figure 7. Double decidual sac sign. US image of an early IUP demonstrates two hyperechoic rings (arrows). The inner ring represents the combined chorion-decidua capsularis, and the outer ring represents the decidua parietalis.