Unit 5 - 1st Trimester Risk Assessment

1st Trimester Pitfalls:

• Correct bladder filling essential for TA

• Any question, perform vaginal exam

• Scan all sacs thoroughly for embryos

• Use appropriate transducer frequencies, gain settings, TGC settings

What is this image?

TA exam, without full enough bladder

What are the invasive procedures that can assess 1st trimester risks?

• Chorionic Villi Sampling

• Amniocentesis

What is a Chorionic Villi Sampling?

Samples some of the placental tissue

What is an Amniocentesis?

Sampling amniotic fluid around baby

What is the function of Serum Biochemical Markers?

Evaluate certain serum levels

A triple screen evaluates what serum levels?

• hCG

• Estriol

• AFP

A quad screen evaluates what serum levels?

• hCG

• Estriol

• AFP

• Inhibin

What 2 risk assessments procedures are blood tests?

• Serum Biochemical Markers

• Serum free cell DNA [fcDNA]

What sonography risk assessment is commonly used?

Nuchal Translucency (NT) measurements

What is this image?

Normal Nuchal Lucency

What is this image?

Normal Nuchal Lucency

What is this image?

Normal Nuchal Lucency

Nuchal Translucency measurements can be an indicator of …

Specific processes; down syndrome

What is the sonographic appearance of Nuchal Translucency?

Cystic space right behind the babies’ neck

When performing a Nuchal Translucency measurement procedure, what is needed in the image when the measurement is taken?

The nasal bone [profile]

When is the Nuchal Lucency measured?

Between 10-14 weeks

The Nuchal Lucency should measure ______.

< 3mm

What is this image?

Normal Nuchal Lucency

What is this image?

Abnormal Nuchal Lucency

What is the correct way for the Nuchal Lucency to be measured?

From inside of fetal neck to inside of nuchal membrane

A Nuchal Lucency measuring > 3mm has been associated with ________ ____________.

Chromosomal Abnormalities

What is this image?

Abnormal Nuchal Lucency

What is this image?

Abnormal Nuchal Lucency

What is some 1st trimester markers of Down’s Syndrome?

• > 3mm Nuchal Lucency

• Absence / hypoplasia of the nasal bone

• Reversal of flow in the Ductus Venosus

What abnormality significantly increases the risk of Down’s Syndrome?

Absent nasal bone

What is the sonographic appearance of the nasal bone?

Little echogenic area

What is this image?

Normal nasal bone

What is this image?

Abnormal nasal bone