Cole Laurence A, Khanlian Sarah A, Sutton Jaime M, Davies Suzy, Rayburn William F
USA hCG Reference Service, Department of Obstetrics and Gynecology, School of Medicine, University of New Mexico, Albuquerque, NM 87131, USA.
Am J Obstet Gynecol. 2004 Jan;190(1):100-5. doi: 10.1016/j.ajog.2003.08.043.
The purpose of this study was to investigate the validity of home pregnancy tests (HPTs) around the time of the missed menses.
Levels of human chorionic gonadotropin (hCG) were determined in urine around the time of the missed menses, and 5th and 95th centiles were calculated. In a blind study evaluating 18 brands of HPTs, each was tested six times with five concentrations of hCG, 0 to 100 mIU/mL. Sensitivity was defined as the concentration at which six of six brands gave positive results, at the suggested reading time or at an extended time.
It was estimated that a sensitivity of 12.5 mIU/mL was needed to detect 95% of pregnancies at the time of missing menses. Only 1 of 18 HPTs had this sensitivity. If faintly discernible results considered, 2 of 18 brands gave false-positive or invalid results. Clear positive results were given by only 44% of the brands at 100 mIU/mL hCG. If one accepted faintly discernible and extended reading times, all brands responded at 100 mIU/mL. A test with 100 mIU/mL sensitivity would detect approximately 16% of pregnancies at the time of missed menses.
The utility of HPTs is questioned. Clinicians need to be aware of the limitations of current HPT brands.
本研究旨在调查月经推迟时家用妊娠试验（HPT）的有效性。
在月经推迟时测定尿液中人绒毛膜促性腺激素（hCG）水平，并计算第5和第95百分位数。在一项评估18个品牌HPT的盲法研究中，每个品牌用0至100 mIU/mL的5种hCG浓度进行6次测试。敏感性定义为在建议的读取时间或延长时间时，6个品牌中有6个给出阳性结果的浓度。
据估计，月经推迟时检测95%的妊娠需要12.5 mIU/mL的敏感性。18种HPT中只有1种具有这种敏感性。如果考虑微弱可辨别的结果，18个品牌中有2个给出假阳性或无效结果。在hCG为100 mIU/mL时，只有44%的品牌给出明确的阳性结果。如果接受微弱可辨别的结果和延长的读取时间，所有品牌在hCG为100 mIU/mL时均有反应。敏感性为100 mIU/mL的测试在月经推迟时可检测到约16%的妊娠。
HPT的效用受到质疑。临床医生需要意识到当前HPT品牌的局限性。
