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 Clinodactyly is an inward position Ansert p. 718 image 32-12 Callen’s Look at p. 50 Table 3-2

Increased Nucal Lucency Vs Cystic Hygroma Abnormal

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 Clinodactyly is an inward position Ansert p. 718 image 32-12 Callen’s Look at p. 50 Table 3-2

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 Image ansert p. 790 37-35 , 37-36

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 Refer to Ansert p. 719 for complete list

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 Midline defect

Fetal Kidneys Fetal pyelectasis-Mild

Single Umbilical Artery