OBSTETRICAL ULTRASOUND

CONGENITAL DISORDERS

Sonographic Markers for Chromosomal Anomalies Nuchal translucency Echogenic bowel Choroid plexus cysts Intracardiac echogenic foci Fetal pyelectasis Nuchal fold Mild ventriculomegaly Shortened longed bones Single umbilical artery

Nuchal Translucency 10-14 weeks of gestation, posterior

to the neck skill for accuracy of measurement > 3mm has association with

chromosomal abnormality > 4 higher risk

Nucal Translucency Normal < 3 mm

DOWN’S SYNDROME Trisomy 21 Physical features

brachycephaly nuchal fold flattened nose- Absent Septum protruding tongue

Trisomy 21 Possible Sonogaphic findings

nuchal translucency > 3 mm nuchal fold increased thickness > 6mm cardiac defects - AV canal

Echogenic foci duodenal atresia shortened extremities clinodactyly of fifth finger

Increased Nucal Lucency Vs Cystic Hygroma

Abnormal NT Nuchal Translucency

Trisomy 21 Nucal fold Excess soft tissue in the posterior

neck area(nucal fold) is known to be a feature of newborns with down syndrome

15-20 wks gestation Nuchal fold abnormal if increased

thickness > 6mm

Absent Nasal Bones Normal Nasal Bones

DILATED VENTRICLES

Echogenic Bowel Meconium Peritionitis

Choroid Plexus Cyst Round or oval anechoic structure

found in the choroid plexus contains cerebral spinal fluid can be unilateral or bilateral range in size from 0.3 mm - 2cm usually resolve by 22-26 weeks considered incidental but can be

associated with trisomies 18 and 21

Choroid Plexus Cyst

Echogenic Foci Fetal Heart

Trisomy 18 Edward’s syndrome Trisomy E or Trisomy 16/18 MSS markers are all decreased Extra Chromosome # 18

poor prognosis Micronathia - small chin low set ears cerebral anomalies Microcephaly “strqwberry shaped skull” clenched hands

Micronathia

“Clenched Hands” Trisomy 18

Trisomy 13 Sonographic Findings IUGR Polyhydraminos Congenital heart disease Midline defects Cranial malformations Extremity anomalies Renal malformations Omphalocele

Cleft Lip

Fetal Kidneys Fetal pyelectasis-Mild

Single Umbilical Artery