The indicator of monochorionicity on ultra-sound Is (LQ)
|C||double decidual sign|
|D||mickey mouse sign|
a. Monochorioniicity is identified by the T sign, the T being formed by the dividing membrane between the two sacks with no elevation of the villi into the intertwine membrane.
b. Dichorionicity is identified by the λ sign that is formed by the placenta and a triangular elevation of the villi into the intertwin membrane. The best time to establish chorionicity is 9 weeks.
c. Mickey mouse sign is seen in anencephaly. A double decidual sac sign (DDSS) is a useful feature on early pregnancy ultrasound in distinguishing between an early intrauterine pregnancy (IUP) and a pseudogestational sac.
d. It consists of the decidua parietalis (that lining the uterine cavity) and decidua capsularis (lining the gestational sac) and is seen as two concentirc rings aurrounding an anechoic gestational sac. Where the two adhere, is the decidua basalis, and is the site of future placental formation.