TEACHER’S GUIDE
Teacher’s guide
The following documents have been produced using data from recent journal
articles. Also included for use in this section are PowerPoints and
information leaflets.
Suggestion for delivering the topic
Use the PowerPoints provided to deliver an introduction on the topic. A
PowerPoint can be produced using a selection of slides from each of the
presentations provided and the information adapted to suit the class.
Students can be put into small groups to complete the activities , for example
in a round-robin set-up. Students complete each activity and when they move
onto the next activity they will find the answers to the previous activity.
Students mark their own work before completing the next activity.
If students are given an introductory presentation there will be no need for a
set order in which the activities are carried out.
At the end of the set of activities students can complete the learning outcome
sheets. There is a space for students to traffic light the outcome, hence the
term code stands for red/amber/green.
Activities provided for suggested round-robin
1.
Down’s syndrome
An activity that highlights the causes of Down’s syndrome and give
students the opportunity to interpret and draw pedigree charts.
2.
Nuchal translucency
An activity that gives more details on this aspect of ultrasound
screening. The activity highlights the relationship between thickness of
NT and chance of malformation and also that a very large NT
measurement is not diagnostic. The activity gives the oppo rtunity for
producing graphs and carrying out calculations using first -hand data.
3.
Foetal abnormalities in context
This activity is designed to try and dispel the myth that ultrasound
screening is all about Down’s syndrome. The activity also gives further
opportunity for analysis of first-hand data and to make inferences based
on trends in the data.
ANTENATAL SCREENING (H, HUMAN BIOLOGY)
© Learning and Teaching Scotland 2011
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TEACHER’S GUIDE
4.
Screening tests
This activity will give the opportunity for students to gain a greater
understanding of the difference between a screening test and a
diagnostic test. Students should also be more able to describe the
factors screened for in prenatal care and be able to explain the
importance of accurate dating of pregnancy in relation to screening
tests. Students should also gain a greater understanding o f falsepositive and false-negative results. The PowerPoint showing ultrasound
images can be used to print off slides to show features that are screened
for in an anomaly scan.
5.
Diagnostic tests
The two booklets ‘Chorionic villus sampling – information for parents’
and ‘Amniocentesis test – information for parents’ need to be available
for students to use to make notes.
It is hoped that this section of the course and these activities will stimulate
discussion on the wider implications of prenatal diagn osis and allow students
to explore their own values when it comes to the difficult decisions that may
need to be made. Also, it is hoped that the activities will highlight that
prenatal diagnosis is not all about Down’s syndrome. It is also hoped that
students will gain an understanding that prenatal diagnosis is not about ‘seek
and destroy’; medical advances mean that there are now far more options
available when making decisions about a foetus with malformations.
It is anticipated that five round robin activities should take no longer than a
typical double period. There are some aspects of the activities that are
designed to stretch more able students and it is anticipated that many students
may need direction to complete some of the more challenging data analysis
questions.
The glossary can be enlarged and used as posters during the topic or
laminated and passed between students when needed. This will encourage
attention to correct spelling and remind students of definitions.
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TEACHER’S GUIDE
Bibliography
Journal articles used for information
B. Dane, C. Dane, A. Cetin, M. Kiray, D. Sivri and M. Yayla. Pregnancy
outcome in fetuses with increased nuchal translucency. Journal of
Perinatology 2008; 28: 400–404.
L. D. Allan. The mystery of nuchal translucency. Cardiology in the Young
2006; 16: 11–17. © Cambridge University Press.
T. Reynolds, G. Vranken, J. Van Nueten and J. Aldis. Down’s syndrome
screening: population statistic dependency of screening performance . Clinical
Chemistry and Laboratory Medicine 2008; 46(5): 639–647.
K. Spencer, V. Souter, N. Tul, R. Snijders and K. H. Nicolaides. A screening
program for trisomy 21 at 10–14 weeks using fetal nuchal translucency,
maternal serum free β-human chorionic gonadotropin and pregnancy associated plasma protein-A. Ultrasound in Obstetrics Gynecology 1999; 13:
231–237.
A. Sau, K. Langford, B. Auld1 and D. Maxwell. Screening for trisomy 21: the
significance of a positive second trimester serum screen in women screen
negative after a nuchal translucency scan. Journal of Obstetrics and
Gynaecology 2001; 21(2): 145–148.
F. Audibert, M. Dommergues, C. Benattar, J. Taieb, J.-C. Thalabard and R.
Frydman. Screening for Down syndrome using first-trimester ultrasound and
second-trimester maternal serum markers in a low -risk population: a
prospective longitudinal study. Ultrasound in Obstetrics Gynecology 2001;
18: 26–31.
G. R. Devore. Trisomy 21: 91% detection rate using second -trimester
ultrasound markers. Ultrasound in Obstetrics Gynecology 2000; 16: 133–141.
V. Bansal, S. Suresh, I. Suresh, S. Jagadeesh, G. J. Fazal. Genetic counseling
in chromosomal abnormalities. Journal of Prenatal Diagnosis and Therapy,
January–June 2010; 1: 14–19.
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