Search

The article discusses a study on the effectiveness of a contingency policy in first-trimester screening for trisomy 21. It mentions the evaluation of the fetal nasal bone, ductus venosus flow and tricuspid flow conducted by skilled sonographers to study the performance of various screening policies. It states that first-trimester screening for trisomy 21 is effective when a contingent screening in which first-stage testing relies on ultrasound examination is used.

OBJECTIVE: To examine the effect of the duration of storage of serum and whole blood at different controlled temperatures on the concentrations of both serum free-beta-human chorionic gonadotropin (beta-hCG) and pregnancy-associated plasma protein-A (PAPP-A) in first-trimester screening for aneuploidies. METHODS: The concentrations of free beta-hCG and PAPP-A were measured in samples collected from 10 pregnant women and stored as whole blood or serum for 1-8 days at 4, 20 or 40 degrees C. The concentrations measured were adjusted to take day-to-day variations into account and were expressed as a percentage of the values on day 0. In a second study involving 10 pregnant women, free beta-hCG was measured at 10 min and at 2, 4, 8 and 12 h after collection and storage at 30 or 40 degrees C, either as separated serum or as whole blood. RESULTS: The change in the levels of PAPP-A in the separated serum at all three temperatures and in whole blood at 4 degrees C was always less than 10% throughout the 8 days of storage. In whole blood stored at 20 and 40 degrees C, the percentage variation was less than 10% only if the storage period was shorter than 4 days. The concentration of free beta-hCG was not altered by storage of either whole blood or separated serum at 4 degrees C throughout the 8 days of storage. At 20 degrees C, reliable results were obtained only if the maximum storage time was 2 days for separated serum and 1 day for whole blood. At 30 degrees C, reliable results were obtained only if the samples were analyzed within 2 h of collection, and at 40 degrees C the concentrations increased by more than 50% within 2 h and by about 500% after 1 day of storage. CONCLUSION: In first-trimester screening for aneuploidies, analysis of blood samples should be undertaken within a few minutes of collection, otherwise the samples should be refrigerated at 4 degrees C throughout the interval between collection and analysis. Copyright (c) 2010 ISUOG. Published by John Wiley & Sons, Ltd. [ABSTRACT FROM AUTHOR]

The article presents the study which aims to analyze the temperature's effect on pregnancy-associated plasma protein-A (PAPP-A) concentration and free β-human chorionic gonadotropin (β-hCG). The study measured the PAPP-A and β-hCG concentrations in samples gathered from pregnant women. Results indicate that blood samples examination should be executed within a couple of minutes of collection in first-trimester aneuploidies screening.