Arulkumaran S, Lilja H, Lindecrantz K, Ratnam S S, Thavarasah A S, Rosén K G
Department of Obstetrics and Gynaecology, National University of Singapore.
J Perinat Med. 1990;18(1):13-22. doi: 10.1515/jpme.1990.18.1.13.
Fetal heart rate (FHR) and fetal electrocardiogram (ECG) recordings were obtained from a scalp electrode with maternal thigh as reference and used for ST waveform analysis in 201 patients in labour. Nearly 45% had suspicious or abnormal FHR traces whilst only 27% had T/QRS ratio greater than 0.25 (mean +/- 2 SD). A normal T/QRS ratio identified 99.3% of fetuses with normal buffering capacity in cord artery blood. Of 13 infants with a cord artery blood pH less than 7.15, standard bicarbonate was less than 15.0 mmol/l in five who had an average T/QRS ratio less than 0.25 throughout labour. Of the eight with respiratory acidosis, five had an increase in T/QRS ratio greater than 0.25 for longer than 20 minutes prior to delivery, in two the ratio increased during the last few minutes and one had no change (pH 7.14). Persistent elevation of T/QRS in the first stage of labour identified those with decrease in buffer capacity in cord arterial blood (sensitivity of 94.1%). Acute hypoxia was recognized by the rapid rise in T/QRS. The specificity of T/QRS to identify fetuses at risk increased by combining the ST waveform analysis with FHR changes.
对201例分娩产妇进行胎儿心率（FHR）和胎儿心电图（ECG）记录，记录采用头皮电极，以母体大腿作为参考，并用于ST段波形分析。近45%的产妇有可疑或异常的FHR轨迹，而只有27%的产妇T/QRS比值大于0.25（均值±2标准差）。正常的T/QRS比值可识别出99.3%的脐动脉血缓冲能力正常的胎儿。在13例脐动脉血pH值小于7.15的婴儿中，有5例在整个分娩过程中平均T/QRS比值小于0.25，其标准碳酸氢盐低于15.0 mmol/L。在8例呼吸性酸中毒的婴儿中，有5例在分娩前T/QRS比值升高大于0.25且持续超过20分钟，2例在最后几分钟比值升高，1例无变化（pH 7.14）。分娩第一产程中T/QRS持续升高可识别出脐动脉血缓冲能力下降的胎儿（敏感性为94.1%）。急性缺氧可通过T/QRS的快速升高识别。将ST段波形分析与FHR变化相结合，T/QRS识别有风险胎儿的特异性增加。
