Autocorrelation and cross-correlation between hCGß and PAPP-A in repeated sampling during first trimester of pregnancy.
Clin Chem Lab Med
; 51(9): 1781-8, 2013 Sep.
Article
en En
| MEDLINE
| ID: mdl-23612665
ABSTRACT
BACKGROUND:
Theoretically, repeated sampling of free ß-human chorionic gonadotropin (hCGß) and pregnancy associated plasma protein-A (PAPP-A) in the first trimester of pregnancy might improve performance of risk assessment of trisomy 21 (T21). To assess the performance of a screening test involving repeated measures of biochemical markers, correlations between markers must be estimated. The aims of this study were to calculate the autocorrelation and cross-correlation between hCGß and PAPP-A in the first trimester of pregnancy and to investigate the possible impact of gestational age at the first sample and time between sampling on the correlation.METHODS:
A prospective study was conducted including 3891 unaffected singleton pregnancies. Two measurements of hCGß and PAPP-A were obtained during the first trimester in each pregnancy. Correlations between the four parameters, hCGß first, hCGß second, PAPP-A first and PAPP-A second, were estimated and presented in terms of Pearson's r coefficients. Furthermore, the correlation between paired samples as a function of time between samples was investigated.RESULTS:
The study demonstrated high correlation between first and second samples of hCGß and PAPP-A with a correlation coefficient of 0.80 and 0.79, respectively. By contrast, the correlations between hCGß and PAPP-A were low. In addition, the study demonstrated that the correlation between paired samples of hCGß and PAPP-A decreases with earlier gestational age at the first sample and with increasing time between samples.CONCLUSIONS:
We have developed a parameter set in terms of correlations between biochemical markers, which can be incorporated into a T21 screening algorithm based on repeated measures within the first trimester.
Texto completo:
1
Colección:
01-internacional
Base de datos:
MEDLINE
Asunto principal:
Proteína Plasmática A Asociada al Embarazo
/
Primer Trimestre del Embarazo
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Gonadotropina Coriónica Humana de Subunidad beta
Tipo de estudio:
Clinical_trials
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Etiology_studies
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Observational_studies
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Risk_factors_studies
Límite:
Adolescent
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Adult
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Female
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Humans
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Middle aged
/
Pregnancy
Idioma:
En
Revista:
Clin Chem Lab Med
Asunto de la revista:
QUIMICA CLINICA
/
TECNICAS E PROCEDIMENTOS DE LABORATORIO
Año:
2013
Tipo del documento:
Article