Herbert W N, Bruninghaus H M, Barefoot A B, Bright T G
Obstet Gynecol. 1987 Apr;69(4):574-7.
The widespread belief that fetal heart tones are first detected with an unamplified fetoscope at about 20 weeks' gestation has been studied prospectively only twice. Using data collection prospectively from 352 visits of 77 patients between 15 and 23 weeks' pregnancy, we studied various clinical aspects of fetal heart tone detection. We determined the gestational age at the time of initial auscultation of fetal heart tones with an ordinary fetoscope, and its relationship to quickening, parity, and placenta location. Fetal heart tones were first identified by auscultation at a mean gestational age of 19.4 weeks (range 17-22 weeks). Detection was possible in 81% of patients examined at 20 weeks and in virtually all patients examined at 21 weeks or later. Once heard, fetal heart tones were identified in every subsequent visit for all patients. Parity and placenta location were significant factors influencing initial fetal heart tone detection. Auscultation preceded quickening in only 12% of patients. Recommendations for using initial fetal heart tone detection in clinical practice are given.
普遍认为在妊娠约20周时使用未放大的胎儿听诊器首次检测到胎儿心音，对此仅进行过两次前瞻性研究。我们前瞻性收集了77例患者在妊娠15至23周期间352次就诊的数据，研究了胎儿心音检测的各种临床情况。我们确定了使用普通胎儿听诊器首次听诊胎儿心音时的孕周，以及它与胎动、产次和胎盘位置的关系。首次通过听诊确定胎儿心音时的平均孕周为19.4周（范围17 - 22周）。在20周接受检查的患者中，81%能够检测到胎儿心音，而在21周或更晚接受检查的几乎所有患者中都能检测到。一旦听到，所有患者在随后的每次就诊中都能再次听到胎儿心音。产次和胎盘位置是影响首次检测到胎儿心音的重要因素。仅12%的患者在胎动前就能听诊到胎儿心音。文中给出了在临床实践中使用首次胎儿心音检测的建议。
