Genetic Sonogram ผศ.พญ.รัตนา คำวิลัยศักดิ์ ผศ.พญ.รัตนา คำวิลัยศักดิ์ การประชุมวิชาการ ครั้งที่ 21 ประจำปี 2548 วันที่ 11 ตุลาคม 2548 ณ ห้องบรรยาย 3 คณะแพทยศาสตร์ มหาวิทยาลัยขอนแก่น

DS Screening Methods First trimester Second trimester • Nuchal translucency • Combined test • Double test Second trimester • Double test • Triple test • Quadruple test • Genetic sonogram First + Second trimester • Integrated test • Serum Integrated test

First Trimester U/S Screening

First Trimester U/S Screening Nuchal translucency Nasal bone hypoplasia

Nuchal Translucency

Nuchal Translucency GA 10-14 weeks CRL 35-84 mm. Abnormal NT > 3 mm. Sensitivity 70% False positive rate 4.3 % Caughey et al. Am J Obstet Gynecol 2002 Nov;187:1239-45.

Nuchal Translucency Accuracy depends on measurement technique Intra-observer variability 0.2+0.27 to 0.33+0.41 Inter-observer variability 0.22+0.22 Mean duration of measurement 8-12 min. Suntharasaj et al. Gynecol Obstet Invest 2005;60:201-05.

Nuchal Translucency X  X

Nasal Bone Hypoplasia

Nasal Bone Hypoplasia GA 11-14 weeks DS Hypoplasia, Absent Nasal bone length < 2.5 mm. Sensitivity 29% Specificity 96% Likelihood ratio 7.3 Odibo et al Obstet Gynecol. 2004;104:1229-33.

Nasal Bone Hypoplasia

Second Trimester U/S Screening

Genetic Sonogram

Target U/S examination Genetic Sonogram Target U/S examination Presence of fetal structural anomalies Presence of aneuploidy markers

Genetic Sonogram Sensitivity FPR Positive LR Vintzileos/1996 Bahado-Singh/1996 Bromely / 1997 Verdin/1998 Nyberg//1998 Sohl/ 1999 Vintzileos/1999 Wax/2000 De Vore/2001 Benn/2002 Bahado-Singh/2002 93% 90% 83% 82% 68% 67% 71% 91% 79.9% 81.8% 13% 14% 17% 10% 12% 9% 6.7% 4.8% 7.2 6.4 4.9 8.2 5.7 3.9 9.1 5.9 7.0 11.9 17.0 Sensitivity FPR Positive LR

Genetic Sonogram Prenasal thickness Nuchal fold thickening Hyperechoic bowel Echogenic intracardiac focus Shortened humerus and femur Widened iliac angle Structural anomalies

Genetic Sonogram Renal Pyelectasis Choroid plexus cyst Hypoplasia of middle phalanx of 5th finger Clinodactyly Sandal gap

Genetic Sonogram Positive LR Nuchal fold thickening 17 (8-38) Shortened humerus Hyperechoic bowel EIF Shortened femur Renal pyelectasis Choroid plexus cyst Positive LR 17 (8-38) 7.5 (4.7-12) 6.1 (3.0-12.6) 2.8 (1.5-5.5) 2.7 (1.2-6.0) 1.9 (0.7-5.1) 1.0 (0.12-9.4)

Prenasal Thickness

Prenasal Thickness Prenasal thickness increases on average in DS fetuses Detection rate 58% FPR 5% PT/NB ratio increases Detection rate 63% FPR 5% Maymon et al. Prenat Diagn. 2005 Aug 8; [Epub ahead of print]

Prenasal Thickness

Nuchal Fold Thickening

Nuchal Fold Thickening GA 15-20 weeks Abnormal thickness NT > 6 mm. The most sensitive and important marker

Shortened Humerus Measured HL Expected HL < 0.9

Hyperechoic bowel

Echogenic Intracardiac Focus

Shortened Femur Measured FL Expected FL < 0.91

Renal Pyelectasis

Renal Pyelectasis GA 16-20 weeks > 4 mm. GA 20-30 weeks > 5 mm.

Choroid Plexus Cyst

Widened Iliac Angle

Widened Iliac Angle Iliac angle > 70 0 Detection rate 63% FPR 22%

Structural Anomalies Omphalocele Duodenal atresia

Structural Anomalies

Clinodactyly Middle phanlanx of 5th finger

Sandal Gap

Genetic Sonogram Positive LR Nuchal fold thickening 17 (8-38) Shortened humerus Hyperechoic bowel EIF Shortened femur Renal pyelectasis Choroid plexus cyst Positive LR 17 (8-38) 7.5 (4.7-12) 6.1 (3.0-12.6) 2.8 (1.5-5.5) 2.7 (1.2-6.0) 1.9 (0.7-5.1) 1.0 (0.12-9.4)

3-Dimensional Ultrasound

Genetic sonogram CANNOT be used to diagnose or exclude aneuploidy Help to adjust the a priori risk of the woman carrying a fetus with DS

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