Department of Clinical Biochemistry, 59892Western General Hospital, Edinburgh, UK.
Ann Clin Biochem. 2022 Jan;59(1):87-91. doi: 10.1177/00045632211045250. Epub 2021 Oct 18.
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.
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.
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.
The current sample receipt protocol in use by the Scottish Down's syndrome screening programme is fit for purpose.
母体血清游离人绒毛膜促性腺激素（游离β-hCG）被用作唐氏综合征胎儿早孕期筛查的生物标志物。游离β-hCG 的产生可以在体外以时间和温度依赖的方式发生；因此，目前苏格兰的筛查方案规定，样本必须在 72 小时内送达实验室。为了评估该方案的有效性，进行了一项审计，以确定运输时间对苏格兰筛查人群母体血清游离β-hCG 中位数倍数（MoM）值的影响。
根据样本运输时间对在一年（2017 年 4 月至 2018 年 3 月）进行的产前筛查中的校正 MoM 值进行分层，并进行比较。为了研究可能的环境温度影响，根据季节对数据进行了拆分，并比较了夏季和冬季的母体血清游离β-hCG 浓度。
在研究中纳入的 28368 个样本中，24368 个样本在采血当天或运输后一天送达。只有 1.5%的样本在运输后 3 天送达。由于运输时间的差异，母体血清游离β-hCG MoM 值的差异并不显著。在夏季和冬季采集的样本中，母体血清游离β-hCG 浓度之间未发现统计学差异。
目前苏格兰唐氏综合征筛查计划中使用的样本接收方案是可行的。
