1. OBSTETRICAL ULTRASOUND
CONGENITAL DISORDERS

2. 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

3. 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

4. Nucal Translucency Normal < 3 mm

5. DOWN’S SYNDROME Trisomy 21
Physical features
brachycephaly
nuchal fold
flattened nose- Absent Septum
protruding tongue

6. 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

7. Increased Nucal Lucency Vs Cystic Hygroma
Abnormal

8. Abnormal NT Nuchal Translucency

9. 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

10. Absent Nasal Bones Normal Nasal Bones

11. DILATED VENTRICLES

12. Echogenic Bowel
Meconium Peritionitis

13. 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 weeks
considered incidental but can be associated with trisomies 18 and 21
Image ansert p , 37-36

14. Choroid Plexus Cyst

15. Echogenic Foci Fetal Heart

16. 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

17. Micronathia

18. “Clenched Hands” Trisomy 18

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

20. Cleft Lip
Midline defect

21. Fetal Kidneys
Fetal pyelectasis-Mild

22. Single Umbilical Artery