Anomaly Screening Flashcards
What is the most common pathophysiology of trisomy 21
Non- dysjunction (95%)
Translocation (5%)
Incidence of trisomy 21
1:700 live births
What conditions cause low AFP(3)
Trisome 21
Trisomy 18
Diabetes mellitus
What causes high AFP (5)
- neural tube defects
- exomphalos
- anencephaly
- duodenal atresia
- multiple gestation
What are the features of a meningomyelocele
- banana shaped cerebellum 99%
- hydrocephalus 70%
Classification of ventriculomegaly
- mild: lateral ventricle 10-12mm
- mod: LV 12.1-15mm
- sev: LV >15mm
Most common site of spina bifida
Lumbosacral region
Choroid plexus cyst + fetal anomalies
Likely diagnosis?
Trisomy 18 (50%)
Indications for fetal echocardiogram
History related(4)
- family history of CHD esp mother (6%) or father (2%)
- previous child with CHD
- uncontrolled pregestational diabetes
- teratogen- lithium
Indications for fetal echocardiogram
Pregnancy related (4)
- increased nuchal translucency
- other fetal anomalies
- fetal hydrops
- fetal arrhythmia
Most common features of trisomy 21(6)
- duodenal atresia
- AVSD
- VSD
- nuchal thickening
- mild ventriculomegaly
- sandal gap toe
Features of trisomy 18 (5)
- choroid plexus cyst
- clenched fist
- rockerbottom feet
- strawberry skull
- micrognathia
Features of trisomy 13 (5)
- holoprosencephaly
- midline or bilateral facial cleft
- iugr
- polydactyly
- Cardiovascular
Incidence of anencephaly
1:1000
When does physiological gut herniation occur
9-12 weeks