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

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.

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Maternal serum screening for neural tube defects and Down's syndrome

The Medical Journal of Australia ◽

10.5694/j.1326-5377.1991.tb142273.x ◽

1991 ◽

Vol 155 (4) ◽

pp. 280-280

Author(s):

Paul T Dignam

Keyword(s):

Neural Tube ◽

Neural Tube Defects ◽

Down's Syndrome ◽

Down’S Syndrome ◽

Maternal Serum ◽

Maternal Serum Screening ◽

Serum Screening

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Maternal serum screening for neural tube defects and Down's syndrome

The Medical Journal of Australia ◽

10.5694/j.1326-5377.1991.tb142124.x ◽

1991 ◽

Vol 155 (2) ◽

pp. 67-68 ◽

Cited By ~ 14

Author(s):

Evelyn F Robertson

Keyword(s):

Neural Tube ◽

Neural Tube Defects ◽

Down's Syndrome ◽

Down’S Syndrome ◽

Maternal Serum ◽

Maternal Serum Screening ◽

Serum Screening

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

Annals of Clinical Biochemistry International Journal of Laboratory Medicine ◽

10.1177/00045632211045250 ◽

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.

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