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First Trimester Anatomy –current standard of care

Dr Anna LeeCOGU Consultant MMC FDU

• Role of 12 week anatomy scan– Historical perspective– Era of NIPT

• What does the literature say is possible?

• What do the guidelines say?• What is ideal/achievable?

First Trimester Anatomy - Current Standard of Care:OVERVIEW

• 11-13/40 US widely used for:– Confirm “viability”– GA– Multiple pregnancy and

chorionicity– Screening for aneuploidy– Diagnosis of non-

chromosomal abnormality

Why do we do it?

• 1972 – Anencephaly diagnosed at 17/40 (Campbell Lancet)• 1980s

• Early attempts at anatomy of T1 fetus• CVS developed

• Aneuploidy screening evolved:

• Maternal age >35• Soft markers at T2 scan• NT noted to be increased in T21 (Szabo The Lancet 1990).

• World wide systemic screening program established (Nicholaides BJOG 1992)

• In parallel:• Achiron – anatomy (ObGyn 1994)

• Gembruch – Cardiac (ObGyn 1990)• These were the exceptions

• Technological advances with HR probes.

• NIPT

How did we get here?

• Women want REAL and MEANINGFUL information about the wellbeing of their pregnancy– No doubt NIPT is superior for

aneuploidy– Structural defects – 1:50– Microdup/del - 1:250– Trisomy 21 - 1:500

• Need combination of NIPT AND US

What is role of T1 US in era of NIPT? What is the role of T1 US in era of NIPT?

• Thickened NT– Needs invasive testing regardless

of NIPT (atypical/false negatives)– Powerful marker for anatomical

abnormality anyway• Cardiac/omphalocele/CDH/skeletal

dysplasias/syndromes– Need to look DIRECTLY at

anatomy

What is role of T1 US in era of NIPT?

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What is the role of T1 US in the era of NIPT?

What is role of T1 US in era of NIPT?

Chaoui, ISUOG 2019

What is the role of the T1 US in the era of NIPT?

• What hasn’t changed?– Size of fetus– Size of mothers– Need for accuracy– Need to counsel

accurately– Need to be realistic

• 13 is better than 11

• What has changed?– Equipment/technology/

digital processing– Expectations – T1

screening and early diagnosis – “why not diagnose it in T1?”

– Growing academic and professional interest –pushing the boundaries of what is possible

What is role of T1 US in era of NIPT? What does the literature say?What does the literature say?

Overall detection rate of major abnormalities in varying populations: 32-61% (Karim JN

USOG 2017), 51%(Prefumo SR Obstet Gynecol 2013)

Landmark paper – Syngelaki et al USOG 2019100997 patients scanned between 11-13+6/40, 2009-2018

Syngelaki – results

• 1720 abnormalities (1.7%)

– 28% T1– 54% T2

– 18% T3/PN

• Incidence of increased NT higher in those with structural abnormality 12% vs 4%

– 22% of those with cardiac abnormality

– 48% if cardiac abnormality detected in T1.

Syngelaki: Results - OVERVIEW

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Syngelaki Results - NEURO

Chaoui ISUOG 2019

Syngelaki: Results - NEURO Syngelaki Results - CARDIAC

Chaoui ISUOG 2019

Syngelaki: Results - CARDIAC

Syngelaki Results - SKELETALSyngelaki: Results - SKELETAL Syngelaki Results – common abnormalities detected in <10%

Syngelaki: Results – common abnormalities “NEVERDETECTED”

What do we need in practice to achieve this?

• Experienced examiner

• Good transducer• Colour doppler

(ALARA pple)• TV TAS • Systemic -

PROTOCOL

What do we need in practice to achieve this? Routine/ProtocolRoutine / Protocol

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Routine/ProtocolRoutine / Protocol Remember: NT view much more than the NT

1. NB2. Palate3. Diencephalon4. BS5. ICT6. NT

Remember – NT view much more than the NT

HEAD - axial Face - axial

SPINE – coronal/sagittal CHEST/CARDIAC - axial

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CARDIAC - LVOT CARDIAC - RVOT

CARDIAC ABDOMEN – axial/sagittal or coronal

LIMBS – axial and sagittal OTHER

• Placental insertion and cord• Cervical length• Uterine anatomy• Adnexal pathology

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CONCLUSION• Technology advances

mean T1 views of anatomy are approaching those of T2

• Low threshold for TVUS• Be systemic/use protocol• T1 US should aim to

assess the HEALTH of the pregnancy – patients want real and meaningful answers as early as possible

Conclusion Acknowledgements

• Syngelaki et al USOG 2019; 54:468-476• Quarello et al USOG 2017; 49:224-230• Springhall et al AJUM 2018; 21: 125-137• ISUOG Practice Guideline USOG 2013;41: 102-113• Chaoui Keynote Lecture ISUOG Congress Berlin

2019

Acknowledgements