Empirical Validation of Risk Screening for Down's Syndrome

1996 ◽  
Vol 3 (4) ◽  
pp. 185-187 ◽  
Author(s):  
N J Wald ◽  
A K Hackshaw ◽  
W Huttly ◽  
A Kennard
Keyword(s):  
Maternal Age ◽  
Risk Group ◽  
Down's Syndrome ◽  
Down’S Syndrome ◽  
Maternal Serum ◽  
Individual Risk ◽  
Triple Test ◽  
Risk Estimates ◽  
Screening Performance ◽  
Predicted Risk

Objective— To validate individual risk estimates in antenatal serum screening for Down's syndrome. Methods— Women screened for Down's syndrome using maternal serum a fetoprotein (AFP), unconjugated oestriol (uE3), and human chorionic gonadotrophs (hCG) with maternal age (the triple test) or AFP, uE3, free β subunit and free a subunit of hCG with maternal age (the quadruple test) were grouped according to their predicted risk of having an affected pregnancy. The mean predicted risk in each category was then compared with the observed prevalence based on the number of affected and unaffected pregnancies in each category. Subjects— About 100 000 pregnant women screened for Down's syndrome from 1989 to 1995. Results— There was close agreement between the predicted term risk and the prevalence at birth for both the triple test and the quadruple test. For example, with the quadruple test the predicted risk in the highest risk group was 1 in 3.3 and the prevalence was 1 in 2.6; in the lowest risk group these were 1 in 3000 and 1 in 2300 respectively. Conclusion— Risk estimates based on multiple marker screening for Down's syndrome are accurate. The technique used to demonstrate this is simple and offers a useful empirical check on screening performance.

scholarly journals Second trimester screening for Down's syndrome using maternal serum dimeric inhibin A

1998 ◽  
Vol 5 (3) ◽  
pp. 115-119 ◽  
Author(s):  
J E Haddow ◽  
G E Palomaki ◽  
G J Knight ◽  
D L Foster ◽  
L M Neveux
Keyword(s):  
Down's Syndrome ◽  
Down’S Syndrome ◽  
The United States ◽  
Serum Markers ◽  
Maternal Serum ◽  
Human Chorionic Gonadotrophin ◽  
Second Trimester ◽  
Serum Samples ◽  
Inhibin A ◽  
Screening Performance

Objectives To determine the second trimester Down's syndrome screening performance of maternal serum dimeric inhibin A, both alone and in combination with existing serum markers. Setting A case-control set of serum samples from patients with Down's syndrome (52) and subjects with matched unaffected pregnancies obtained in a previous cohort study before second trimester amniocentesis and karyotyping. The amniocenteses were performed for reasons other than a positive serum screening test result. Methods For each serum from a Down's syndrome pregnancy, five serum samples from pregnancies with a normal karyotype were matched for recruitment centre, gestational age, maternal age, and date of amniocentesis. A specific form of inhibin (dimeric inhibin A) was measured using monoclonal antibodies. Measurements of α fetoprotein, unconjugated oestriol, and human chorionic gonadotrophin and its free β subunit were already available. Screening performance was modelled using distribution variables of the analytes coupled with the 1993 age distribution of pregnant women in the United States. Results The median dimeric inhibin A level was 2.10 times higher in Down's syndrome pregnancies. When dimeric inhibin A was combined with maternal age and three other serum markers (α fetoprotein, unconjugated oestriol, and human chorionic gonadotrophin) the Down's syndrome detection rate increased to 75% (from 66%) at a 5% false positive rate. If dimeric inhibin A could be added for less than $31 (ranging from $16 to $39 depending on the detection rate, markers chosen, and method of dating), the cost of detecting each Down's syndrome pregnancy and the number of procedure related fetal losses would both be reduced. Conclusions The addition of dimeric inhibin A to prenatal screening programmes for Down's syndrome should be considered, or possibly it could be substituted for an existing serum marker. One barrier to implementation in the United States, however, is the unavailability of kits with Food and Drug Administration approval.

Risk of fetal Down's syndrome based on maternal age and varying combinations of maternal serum markers

1994 ◽  
Vol 255 (2) ◽  
pp. 57-64 ◽  
Author(s):  
I. Bartels ◽  
B. Bockel ◽  
J. Caesar ◽  
M. Krawczak ◽  
M. Thiele ◽  
...  
Keyword(s):  
Maternal Age ◽  
Down's Syndrome ◽  
Down’S Syndrome ◽  
Serum Markers ◽  
Maternal Serum

scholarly journals Trisomy18 fetuses with cystic hygroma linked to positive maternal serum Down's syndrome Triple test screening result

2005 ◽  
Vol 12 (4) ◽  
pp. 203-203 ◽  
Author(s):  
Claudio Celentano ◽  
Paolo Emilio Guanciali-Franchi ◽  
Marco Liberati ◽  
Federico Prefumo ◽  
Giandomenico Palka ◽  
...  
Keyword(s):  
Down's Syndrome ◽  
Down’S Syndrome ◽  
Cystic Hygroma ◽  
Maternal Serum ◽  
Triple Test ◽  
Screening Result

scholarly journals Assessment of Atypicality: An Adjunct to Prenatal Screening for Down's Syndrome That Facilitates Detection of other Abnormalities

1993 ◽  
Vol 30 (6) ◽  
pp. 578-583 ◽  
Author(s):  
D E Wright ◽  
T M Reynolds ◽  
C M Donovan
Keyword(s):  
Prenatal Screening ◽  
Down's Syndrome ◽  
Down’S Syndrome ◽  
Maternal Serum ◽  
Chorionic Gonadotrophin ◽  
Human Chorionic Gonadotrophin ◽  
Low Risk ◽  
Risk Estimates ◽  
Risk Reporting

Current software used for assessment of the risk of Down's syndrome may give misleading risk estimates if applied to other abnormalities. Often the abnormality is reflected in maternal serum α-fetoprotein and human chorionic gonadotrophin levels and is then translated into a low risk for Down's syndrome that may not be recognized as significantly atypical of normality. We regard this as a serious deficiency in the current Down's syndrome risk reporting algorithm, and suggest a modification that allows the problem to be overcome.

Risk of fetal Down's syndrome based on maternal age and varying combinations of maternal serum markers

1994 ◽  
Vol 255 (2) ◽  
pp. 57-64
Author(s):  
I. Bartels ◽  
B. Bockel ◽  
J. Caesar ◽  
M. Krawczak ◽  
M. Thiele ◽  
...  
Keyword(s):  
Maternal Age ◽  
Down's Syndrome ◽  
Down’S Syndrome ◽  
Serum Markers ◽  
Maternal Serum

Incidence of Down's Syndrome by Maternal Age of Asian Population

2020 ◽  
Author(s):  
Song Yi ◽  
Jieping Song ◽  
Feng Liu ◽  
Xu Liu ◽  
Chengcheng Zhang ◽  
...  
Keyword(s):  
Maternal Age ◽  
Down's Syndrome ◽  
Asian Population ◽  
Down’S Syndrome

Stability of maternal serum free β-hCG following whole blood sample transit: First trimester Down’s syndrome screening in Scotland

2021 ◽  
pp. 000456322110452
Author(s):  
Angela Ballantyne ◽  
Lorna Rashid ◽  
Rebecca Pattenden
Keyword(s):  
Transit Time ◽  
Down's Syndrome ◽  
Down’S Syndrome ◽  
First Trimester ◽  
Maternal Serum ◽  
Dependent Manner ◽  
Serum Free ◽  
Β Hcg ◽  
In Transit ◽  
The Impact

Background Maternal serum free beta human chorionic gonadotrophin (free β-hCG) is used as a biomarker in first trimester screening for fetal Down’s syndrome. Production of free β-hCG can occur in vitro in a time- and temperature-dependent manner; thus, the current Scottish screening protocol states samples must be received by the laboratory within 72 h. To assess the validity of the protocol, an audit was conducted to determine the impact of transit time on maternal serum free β-hCG multiple of median (MoM) values in the Scottish screened population. Methods Corrected MoM values from antenatal screening carried out over one year (April 2017 to March 2018) were stratified according to sample transit time and compared. To investigate possible environmental temperature effects, the data were split according to season and maternal serum free β-hCG concentrations from summer and winter compared. Results Of the 28,368 samples included in the study, 24,368 were received on the day of phlebotomy or after one day in transit. Only 1.5% of samples were received after 3 days in transit. The difference in maternal serum free β-hCG MoM values due to transit time was not significant. No statistical difference was found between maternal serum free β-hCG concentrations from samples collected in summer and winter months. Conclusion The current sample receipt protocol in use by the Scottish Down’s syndrome screening programme is fit for purpose.

Low second trimester maternal serum unconjugated oestriol in pregnancies with Down's syndrome

1988 ◽  
Vol 95 (4) ◽  
pp. 330-333 ◽  
Author(s):  
J. A. CANICK ◽  
G. J. KNIGHT ◽  
G. E. PALOMAK1 ◽  
J. E. HADDOW ◽  
H. S. CUCKLE ◽  
...  
Keyword(s):  
Down's Syndrome ◽  
Down’S Syndrome ◽  
Maternal Serum ◽  
Second Trimester
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