Screening Tests
Neural Tube Defects
Morrow RJ, McNay MB and Whittle MJ.
Ultrasound detection of neural tube
defects in patients with elevated maternal
serum AFP levels.
Obstet Gynecol 1991; 78:1055-7, Abstract.
In a study of 905 pregnant women with
raised alpha feto-protein, ultrasound scanning
had 98% sensitivity and 100% specificity
for the detection of neural tube defects.
The positive predictive value was 100%
and the negative predictive value 99.9%.
Down's Syndrome
National Screening Committee
http://www.nsc.nhs.uk/antenatal_screen/antenatal_screen_ind.htm
Provides current recommendations for antenatal screening.
Serum Screening
Gilbert RE, Augood C, Ades AE, Logan
S, Sculpher M, van Der Meulan JH.
Screening for Down's syndrome: effects,
safety and cost effectiveness of first
and second trimester strategies.
BMJ 2001; 323: 423-5, Abstract.
This study considered the safety, outcome
and cost effectiveness of first and second
trimester Down's screening.
Nuchal Translucency
Snijders RJ, Nobel P, Sebire N, Souka
A, Nicolaides KH.
UK multicentre project on the assessment
of risk of trisomy 21 by maternal age
and fetal nuchal translucency thickness
at 10-14 weeks of gestation.
Lancet 1998; 352(9125):343-6, Abstract.
Multicentre study of 96127 women, investigated
for their risk of Trisomy 21 by a combination
of maternal age and nuchal translucency
thickness at 10-14 weeks gestation. Risk
was calculated by maternal age, gestational-age-related
prevalence and multiplied by a likelihood
ratio derived from the deviation from normal
of the Nuchal translucency measurement.
The sensitivity of a cut off risk of 1
in 300 was investigated. Phenotype was
derived from fetal karyotype or clinical
examination of liveborn infants. The estimated
Trisomy 21 risk was > 1in 300 for 8.3%
of normal pregnancies, 82.2% of those with
Trisomy 21 and 77.9% of those with other
chromosomal defects. 80% of affected pregnancies
were identified using the above screening
method to determine -those offered invasive
testing.
SURRUS- The Serum, Urine and Ultrasound
Study
This 5 year national study is due to report
in autumn 2002. It will examine the effectiveness
of the range of antenatal screening methods
available in the United Kingdom. It is
expected to influence future recommendations
for practice via the National Screening
Committee and National Institute for Clinical
Effectiveness.
Back
to the "Information for Professionals" page
|
