Ultrasound findings after screening for Down syndrome using the integrated test.
OBJECTIVE
To evaluate the incidence and significance of fetal anomalies and "soft markers" after screening for Down syndrome using the integrated test.


METHODS
This study is a retrospective study of 2,332 women at University College London Hospitals, United Kingdom. All women were screened for Down syndrome by the integrated test. Subsequently, a detailed anomaly scan was performed. All scan reports and screening results were analyzed statistically using SPSS 11.0 software.


RESULTS
Sixty-eight (2.9%) patients were categorized as high risk. There were 12 cases affected by Down syndrome, 10 (10 of 68) in the high-risk group and two (two of 2,264) in the low-risk group. Soft markers or structural anomalies were found in 13.0% of the low-risk group, in 29.4% of the high-risk group, and in 50% of the fetuses affected by Down syndrome. Multiplying the likelihood ratio of each marker with the risk of Down syndrome from the integrated test reduced the false-positive rate of the integrated test from 2.5% to 1.8%, but was accompanied by a reduction in the detection rate from 83% to 75%.


CONCLUSIONS
Absence of structural anomalies or markers should not prevent offering karyotyping to women in the high-risk group, because this would result in a significant reduction in the detection rate of Down syndrome. Women screened as low risk by the integrated test who have isolated soft markers should not be offered an amniocentesis.
Weisz
Boaz
B
Department of Obstetrics and Gynaecology, University College London and Wolfson Institute of Preventive Medicine, St. Bartholomew's and Royal London School of Medicine and Dentistry, London, United Kingdom.boazmd@zahav.net.il
Pandya
Pranav P
PP
David
Anna L
AL
Huttly
Wayne
W
Jones
Patricia
P
Rodeck
Charles H
CH
D000293:Adolescent; D000328:Adult; D004314:Down Syndrome / Q000175:diagnosis* / Q000000981:diagnostic imaging; D005189:False Positive Reactions; D005260:Female; D006801:Humans; D016013:Likelihood Functions; D008875:Middle Aged; D048208:Nuchal Translucency Measurement; D011247:Pregnancy; D012189:Retrospective Studies; D018570:Risk Assessment; D016216:Ultrasonography, Prenatal