Trisomy when to suspect in imaging??

.What to image in a trisomy 18 case???  What to look for??  When to suspect trisomy 18  USG ??  Ans:-The salient points are foetal growth  is usually restricted .  CNS abnormalities   associated with Edward syndrome  are choroid  plexus  cyst abnormal  cisterna magna 1) absent   corpus callosum  2) cerebella hypoplasia  3) ventriculomegaly 4) strawberry shaped calvarium  and  5) neural tube defects. Skeletal abnormalities include   6) limb reduction defects overlapping index finger clubbed  feet 7) rocker bottom feet  and polydactyl.

8) Facial defects  seen are cleft lip and palate  9) micrognathia low set ears and 10) microphthalmos. 11) Cardiovascular abnormalities   associated with  this syndrome are 12)  omphalocele  diaphragmatic hernia hydronephrosis  and horseshoe kidney    . 13) Umbilical cord cysts and double vessels umbilical cord may also be observed.