Routine Anomaly ScanRoutine Anomaly Scan

Ilse Erasmus

Routine Anomaly ScanRoutine Anomaly Scan

Timing:– 18 – 23 weeks

Costs – about R 230 – 00

RCOG Guidelines October 1997RCOG Guidelines October 1997Timing of sonarsTiming of sonars

Best Acceptable Less Accept

Dating 8-10 10-20 24

Viability >7

Twins Anytime

Chorionicity 8-12 13-15

Fetal anomaly 18-20

NT 8-15* 15-16* 18-20*

Routine Anomaly ScanRoutine Anomaly Scan

Waste of resource to request routine anomaly scan in the late second or 3rd trimester

Waste of resource to request growth scan in 3rd trimester in the absence of an early sonar

Routine Anomaly ScanRoutine Anomaly Scan

Indication in SA cost considerations??? Routine late bookers High risk

– Previous fetal/ neonatal anomalies– Previous IUD– AMA– Maternal:– disease index pregnancy / history of– Medication– Congenital anomalies

Routine Anomaly ScanRoutine Anomaly Scan

Cochrane Database

– Reduction in post term inductions– Twin Pregnancies

Radius?!?

Routine Anomaly ScanRoutine Anomaly Scan

Screening?

1/55 babies born with major anomalyStructural anomalies > single gene

defectsUK Fetal anomalies = 15% of perinatal

deaths and 15% of deaths in first year of life

Routine Anomaly ScanRoutine Anomaly Scan

Screening? Six objectives Reassurance that baby is apparently normal Or the identification of: Non –viable anomalies Anomalies associated with high morbidity and long term

handicap Fetal conditions with the potential for intrauterine therapy Fetal conditions requiring postnatal investigation and/ or therapy Parental preparation

Routine Anomaly ScanRoutine Anomaly Scan

Screening? Lethal anomalies – anencheph, BRA, thanatophoric

dwarfs High morbidity and long term handicap – NTD,

cardiac,aneuploidy Potential intrauterine therapy – RH, Parvo,TTS Fetal conditions requiring postnatal investigation and/

or therapy – renal, facial cleft Parental preparation

RCOGRCOG Guidelines October 1997Guidelines October 1997

Detection Rates for Specific anomaliesDetection Rates for Specific anomalies

Anomaly <24w Sensitivity Specificity

Anencheph/Enc 87 – 100% (>95%) 99 – 100%

Intracranial Path 27 – 100% (70%) 99 – 100%

Renal Agenesis 75 - 100% (85%) 99 – 100%

Cystic Lung 0- 100% (100%) 99 – 100%

Cardiac Major 4 – 77% (47%) 98 – 99%

CD hernia 0 – 100% (40%) 99 – 100%

Exomphalos 0 – 100% (>95%) 99 – 100%

Gastroschisis 0 –100% (66%) 0 - 100%

Muscuoloskeletal 0 –100% (50%) 0 - 100%

RCOGRCOG Guidelines October 1997Guidelines October 1997

Detection Rates for Specific anomaliesDetection Rates for Specific anomalies

Anomaly < 24 Sensitivity Specificity

Spina Bifida 69 – 100% (78%) 99 – 100%

Major Renal 26 – 100% (60%) 99 – 100%

RCOG Routine sonar in PregnancyRCOG Routine sonar in PregnancyJuly 2000July 2000

6 year Scottish Study

Booking scan only % Minimum standard scan %

Anencheph 97 100 ( better)

Spina Bifida 61 92 (better)

Major cardiac

(hypoplastic LV)

14 61 (better)

CD Hernia 30 62 (better)

Gastroshcisis 86 100 (better)

Exomphalos 45 92 (same)

Major renal

Renal agenesis

76 85 (better)

RCOG 2000 JulyRCOG 2000 JulyMinimum standard for a 20 week anomaly scanMinimum standard for a 20 week anomaly scan

Gestational age– BPD, HC, FL, AC

MeasurmentsMeasurments

RCOG 2000 JulyRCOG 2000 JulyMinimum standard for a 20 week anomaly scanMinimum standard for a 20 week anomaly scan

Gestational age– BPD, HC, FL, AC

Fetal Normality– Head shape and internal structures

CSP, Cerebellum, Ventricular size at atrium (<10mm)

– Spine longitudinal and transverse– Abdominal shape and content at the level

of the stomach

RCOG 2000 JulyRCOG 2000 JulyMinimum standard for a 20 week anomaly scanMinimum standard for a 20 week anomaly scan

– Renal Pelvis (<5mm AP)– Longitudinal axis – abdominal thoracic

appearance (diaphragm/bladder)– Thorax at level of 4ch cardiac view– Arms – 2 x 3 long bones + hands (not

counting fingers)– Legs - 2 x 3 long bones + feet (not

counting toes)

RCOG 2000 JulyRCOG 2000 JulyMinimum standard for a 20 week anomaly scanMinimum standard for a 20 week anomaly scan

RCOG 2000 JulyRCOG 2000 JulyOptimal standard for a 20 week anomaly scanOptimal standard for a 20 week anomaly scan

– The above plus:– Cardiac outflow tracts– Face and lips

RCOG 2000 JulyRCOG 2000 JulyMarker scansMarker scans

– Not considered “routine”– Isolated markers of dubious value– Increased overall detection rate increase from

51% - 55% but FPR from 1/2332 to 1/188!!!!! (Boyd PA Lancet 1998)

– Two or more markers significant– Screening using maternal age, age + NT, age+

serum will identify 50 – 80%– So marker scan as screening in unscreened

population unlikely to be of use

RCOG 2000 JulyRCOG 2000 JulyMarker scansMarker scans

– “Markers”– CPC– Ventriculomegaly(>10mm at atrium)– Echogenic bowel(equivalent to bone density)– Head shape– Nuchal skinfold thickness(>5mm at 20 weeks)– CM– Cleft lip– Echogenic intracardiac focus

RCOG 2000 JulyRCOG 2000 JulyMarker scansMarker scans

– Dilated renal pelvis(>5mmAP)– Short Femur/Humerus– Talipes– Sandal gap– Clinodactyly– Clenched hand– Two vessel cord

RCOG 2000 JulyRCOG 2000 JulyMarker scansMarker scans

– Other risk factors

– Maternal age > 35– Serum screening results– Nuchal translucency at 11 – 14 weeks

Standard viewsStandard views

Pilu, Nicolaides CD - ROM

ISUOG Standards

Standard viewsStandard views

IntrauterineAmount of fetuses Cardiac activityPlacental Position, AppearanceCord vesselsLiquor

Standard viewsStandard viewsHead and BrainHead and Brain

Standard viewsStandard viewsFaceFace

Standard viewsStandard viewsFaceFace

Standard viewsStandard viewsSpineSpine

Standard viewsStandard viewsHeartHeart

Standard viewsStandard viewsGITGIT

Standard viewsStandard viewsLimbsLimbs

Anomaly scanAnomaly scan

Skull & BrainNormal and abnormal

Anomaly scanAnomaly scan

FaceNormal and abnormal

Anomaly scanAnomaly scan

SpineNormal and abnormal

NormalNormalSpineSpine

Abnormal SpineAbnormal Spine

Anomaly scanAnomaly scan

GITNormal and abnormal

Anomaly scanAnomaly scan

HeartNormal and abnormal

Anomaly scanAnomaly scan

KidneysNormal and abnormal

Anomaly scanAnomaly scan

LimbsNormal and abnormal