Age related detection and false positive rates when screening for Down's Syndrome in the first trimester using fetal nuchal translucency and maternal serum free betahCG and PAPP-A

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.

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Effect of first-trimester nuchal translucency on second-trimester maternal serum biochemical screening for Down's syndrome

Ultrasound in Obstetrics and Gynecology ◽

10.1046/j.1469-0705.1997.10040261.x ◽

1997 ◽

Vol 10 (4) ◽

pp. 261-264 ◽

Cited By ~ 37

Author(s):

B. Thilaganathan ◽

A. Slack ◽

N. C. Wathen

Keyword(s):

Down's Syndrome ◽

Down’S Syndrome ◽

First Trimester ◽

Nuchal Translucency ◽

Maternal Serum ◽

Second Trimester ◽

Biochemical Screening ◽

Serum Biochemical

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First-trimester nuchal translucency and maternal serum biochemical screening for Down's syndrome: a happy union?

Ultrasound in Obstetrics and Gynecology ◽

10.1046/j.1469-0705.1999.13040229.x ◽

1999 ◽

Vol 13 (4) ◽

pp. 229-230 ◽

Cited By ~ 7

Author(s):

B. Thilaganathan

Keyword(s):

Down's Syndrome ◽

Down’S Syndrome ◽

First Trimester ◽

Nuchal Translucency ◽

Maternal Serum ◽

Biochemical Screening ◽

Serum Biochemical

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First trimester screening for Down's syndrome using maternal serum PAPP-A and free beta=hCG in combination with fetal nuchal translucency thickness

BJOG An International Journal of Obstetrics & Gynaecology ◽

10.1111/j.1471-0528.1998.tb10239.x ◽

1998 ◽

Vol 105 (8) ◽

pp. 917-920 ◽

Cited By ~ 24

Author(s):

Roberto Biagiotti ◽

Laura Brizn ◽

Enrico Periti ◽

Albertino d'Agata ◽

Ermanno VanZi ◽

...

Keyword(s):

Down's Syndrome ◽

Down’S Syndrome ◽

First Trimester ◽

Nuchal Translucency ◽

Maternal Serum ◽

First Trimester Screening ◽

Beta Hcg ◽

Trimester Screening

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FIRST-TRIMESTER URINE FREE BETA hCG, BETA CORE, AND TOTAL OESTRIOL IN PREGNANCIES AFFECTED BY DOWN'S SYNDROME: IMPLICATIONS FOR FIRST-TRIMESTER SCREENING WITH NUCHAL TRANSLUCENCY AND SERUM FREE BETA hCG

Prenatal Diagnosis ◽

10.1002/(sici)1097-0223(199706)17:6<525::aid-pd105>3.0.co;2-i ◽

1997 ◽

Vol 17 (6) ◽

pp. 525-538 ◽

Cited By ~ 30

Author(s):

K. SPENCER ◽

P. NOBLE ◽

R. J. M. SNIJDERS ◽

K. H. NICOLAIDES

Keyword(s):

Down's Syndrome ◽

Down’S Syndrome ◽

First Trimester ◽

Nuchal Translucency ◽

First Trimester Screening ◽

Serum Free ◽

Beta Hcg ◽

Trimester Screening

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Screening for aneuploidies by maternal age, fetal nuchal translucency and maternal serum biochemistry at 11-13+6 gestational weeks

Srpski arhiv za celokupno lekarstvo ◽

10.2298/sarh1210606k ◽

2012 ◽

Vol 140 (9-10) ◽

pp. 606-611 ◽

Cited By ~ 1

Author(s):

Natasa Karadzov-Orlic ◽

Amira Egic ◽

Dejan Filimonovic ◽

Maja Marinkovic ◽

Barbara Damnjanovic-Pazin ◽

...

Keyword(s):

False Positive ◽

Trisomy 21 ◽

Maternal Age ◽

False Positive Rate ◽

First Trimester ◽

Nuchal Translucency ◽

Maternal Serum ◽

Trisomy 18 ◽

Serum Free ◽

Positive Rate

Introduction. Aneuploidies are the major cause of perinatal death and early psychophysical disorders. Objective. In this study, we analyzed detection and false-positive rates of screening for aneuploidies in the first trimester by the combination of maternal age, fetal nuchal translucency (NT) thickness and maternal serum free beta-human chorionic gonadotrophin (?-hCG), and pregnancy-associated plasma protein-A (PAPP-A) at 11-13+6 weeks of gestation, using the appropriate software developed by the Fetal Medicine Foundation. Methods. Our screening study for aneuploidies analyzed 4172 singleton pregnancies from January 2006 to December 2010. The sensitivities and false-positive rates using the combined aneuploidies determination for the risk cut-off of 1:275 were evaluated. Results. In the trisomy 21 pregnancies, the fetal NT was higher than 95th centile, in 72.8%, serum free b-hCG concentration it was above the 95th centile in 55% and serum PAPP-A was below the 5th centile in 47% of the cases. In the trisomy 18 and 13, the fetal NT was above 95th centile in 66.6% and 44.4% of the cases, respectively. The serum free b-hCG concentration was above the 95th centile in 0 and 10%, but serum PAPP-A was below 5th centile in 80.9% and 88.8% of pregnancies. In the trisomy 21 pregnancies the median free beta-hCG was 2.3 MoM and the median PAPP-A was 0.45 MoM. Chromosomal abnormalities were detected in 169 fetuses: trisomy 21 (97), Turner syndrome (19), trisomy 18 (28), trisomy 13 (11) and others (14). Detection rate of combined screening for aneuploides were 86.0% with false positive rate of 5.3% (mean age 33?4.9 years, >35 years in 35% of pregnancies). Conclusion. Our study suggests that the strategy of first-trimester combined screening of biochemical values and ultrasonographic parameters at 12 gestational weeks identifies higher percentage of aneuploidies with a lower false-positive rate than a single parameter strategy.

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Maternal serum free α-human chorionic gonadotrophin levels in twin pregnancies: Implications for screening for Down's syndrome

Prenatal Diagnosis ◽

10.1002/pd.1970140811 ◽

1994 ◽

Vol 14 (8) ◽

pp. 717-719 ◽

Cited By ~ 17

Author(s):

N. J. Wald ◽

J. W. Densem

Keyword(s):

Down's Syndrome ◽

Down’S Syndrome ◽

Maternal Serum ◽

Chorionic Gonadotrophin ◽

Human Chorionic Gonadotrophin ◽

Serum Free ◽

Twin Pregnancies

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Screening for Down's Syndrome: The First Two Years Experience in Bristol

Journal of Medical Screening ◽

10.1177/096914139500200407 ◽

1995 ◽

Vol 2 (4) ◽

pp. 207-210 ◽

Cited By ~ 8

Author(s):

D J Goldie ◽

J P Astley ◽

J M Beaman ◽

D A Bickley ◽

A Gunneberg ◽

...

Keyword(s):

False Positive Rate ◽

Down's Syndrome ◽

Down’S Syndrome ◽

District General Hospital ◽

Serum Marker ◽

Serum Markers ◽

Maternal Serum ◽

Age Related ◽

Related Risk ◽

Positive Rate

Objectives – To evaluate the effectiveness of a programme for antenatal screening for Down's syndrome using a fetoprotein and total human chorionic gonadotrophin as maternal serum markers. Setting –A district general hospital providing a screening service to a local purchasing authority and (under contract) to another purchasing authority in the same region. Methods – Patients were counselled and screened between 15 and 20 weeks gestation and Down's risk estimates calculated using the maternal serum marker results as modifiers of the age related risk. Outcome was determined in collaboration with the Regional Cytogenetics Unit. Outcome Measures – Detection rate for Down's syndrome, false positive rate, uptake of screening, and uptake of amniocentesis. Results– In two years 22 816 women were screened (approximately 84% of population); 32 Down's pregnancies were identified, 19 (59.4%) had a reported risk of ≥1:250 and 20 (62.5%) a reported risk of ≥1:300. Of those screened before 17 weeks, 16/20 (80%) had a reported risk of ≥1: 300 compared with 4/12 (33%) of those screened later (P = 0.008); 4.64% of patients screened had reported risks ≥1: 250 and 5.87% reported risks of ≥ 1:300. Amniocentesis uptake was 70% in patients with reported risks of ≥ 1:300. Conclusions –Overall the screening programme was effective but screening before 17 weeks was very much more effective than screening later.

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