The effect of temporal variation in biochemical markers of trisomy 21                across the first and second trimesters of pregnancy on the estimation of individual                patient-specific risks and detection rates for Down's syndrome

Spencer, Kevin; Crossley, Jennifer A.; Aitken, David A.; Nix, A. B. J.; Dunstan, Frank David John; Williams, Karen

doi:10.1258/000456303321610501

Cited by 48 publications

(39 citation statements)

References 18 publications

(26 reference statements)

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“…The low ADAM12 results confirm the early observations of Laigaard et al [17] who demonstrated in a small series of 10 cases that prior to 55 days, levels of ADAM12 were less than the detection limit of the assay and increased as the gestational age increased. This mirrors the temporal pattern that has been described for ADAM12 in pregnancies with trisomy 21 [19,20], and is similar to that described for PAPP-A [31,32], which like ADAM12 is another IGFBP protease [13,33]. However the temporal pattern is unlike that seen for PAPP-A in trisomy 18 when the low levels of PAPP-A in the first trimester are even further reduced in the second trimester [6,34,35].…”

Section: Discussionsupporting

confidence: 84%

ADAM12 as a marker of trisomy 18 in the first and second trimester of pregnancy

Spencer

Cowans

2007

The Journal of Maternal-Fetal & Neonatal Medicine

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Section: Discussionsupporting

confidence: 84%

ADAM12 as a marker of trisomy 18 in the first and second trimester of pregnancy

Spencer

Cowans

2007

The Journal of Maternal-Fetal & Neonatal Medicine

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“…Because NT measurements are not involved, the lower gestational age limit for the first-trimester sample collection can be earlier than 11 weeks' gestation, a time when PAPP-A measurements are more discriminatory. 70 However, laboratories would need to obtain appropriate Down syndrome risk equations and develop reliable median levels before offering the test clinically. Another issue is whether to accept samples that are dated by LMP.…”

Section: Serum Integrated Screening (Nt Measurements Not Available)mentioning

confidence: 99%

Technical standards and guidelines: Prenatal screening for Down syndrome that includes first-trimester biochemistry and/or ultrasound measurements

Palomaki

Lee²,

Canick

et al. 2009

Genetics in Medicine

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Disclaimer: These Standards and Guidelines are designed primarily as an educational resource for clinical laboratory directors to help them provide quality clinical laboratory genetic services. Adherence to these standards and guidelines does not necessarily ensure a successful medical outcome. These standards and guidelines should not be considered inclusive of all proper procedures and tests or exclusive of other procedures and tests that are reasonably directed to obtaining the same results. In determining the propriety of any specific procedure or test, the clinical laboratory director should apply his or her own professional judgment to the specific clinical circumstances presented by the individual patient or specimen. It may be prudent, however, to document in the laboratory record the rationale for any significant deviation from these standards and guidelines.Abstract: This statement is intended to augment the current general ACMG Standards and Guidelines for Clinical Genetics Laboratories and to address guidelines specific to first-trimester screening for Down syndrome. The aim is to provide the laboratory the necessary information to ensure accurate and reliable Down syndrome screening results given a screening protocol (e.g., combined first trimester and integrated testing). Information about various test combinations and their expected performance are provided, but other issues such as availability of reagents, patient interest in early test results, access to open neural tube defect screening, and availability of chorionic villus sampling are all contextual factors in deciding which screening protocol(s) will be selected by individual health care providers. Individual laboratories are responsible for meeting the quality assurance standards described by the Clinical Laboratory Improvement Act, the College of American Pathologists, and other regulatory agencies, with respect to appropriate sample documentation, assay validation, general proficiency, and quality control measures. These guidelines address first-trimester screening that includes ultrasound measurement and interpretation of nuchal translucency thickness and protocols that combine markers from both the first and second trimesters. Laboratories can use their professional judgment to make modification or additions. Genet Med 2009:11(9):669 -681.

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“…Existe una significativa variación temporal de los MoM de los marcadores bioquímicos usados en el cribado de SD a lo largo de la gestación 20,21 , lo cual hace que cada marcador tenga un perfil de eficacia distinto en cada momento de la gestación. Por ello, cuando se usan varios marcadores, se debe elegir el periodo de tiempo ideal en el que su determinación conjunta aumente su eficacia.…”

Section: Discussionunclassified