Tranquilli Andrea L, Biagini Alessandra, Greco Pantaleo, Di Tommaso Mariarosaria, Giannubilo Stefano R
Department Clinical Sciences, Università Politecnica Marche, Ancona, Italy.
J Matern Fetal Neonatal Med. 2013 Sep;26(14):1425-9. doi: 10.3109/14767058.2013.784263. Epub 2013 Apr 17.
To quantify fetal bradycardia in the second stage of labor and to determine the threshold of the area that correlates with neonatal acidemia.
We analyzed the cardiotocograms of 33 women with single pregnancy and term spontaneous labor who presented fetal bradycardia in the second stage of labor. We retrospectively calculated the fetal bradycardia area in the last 60 min before delivery with an upper limit of 90 bpm and correlated the area with neonatal pH. The study of the regression line determined the cut-off threshold between fetal well-being and distress. Significance was set at p < 0.05.
The linear correlation between the bradycardia area and neonatal pH indicate that increasing bradycardia area was correlated with significant pH decrease. The threshold value of the area indicative of severe acidemia was ≥ 12.72 cm(2) (Pearson r = -0.76, p < 0.002). The diagnostic accuracy of the test was 73%. The PPV = 78.5% and the NPV = 68.4%. With such a cut-off, the timing of acidemia can be calculated as 25 min for a fetal heart rate (FHR) of 80 bpm, 13 min for a FHR of 70 bpm, 8 min for a FHR of 60 bpm, 6 min for a FHR of 50 bpm and 5 min for a FHR of 40 bpm.
The bradycardia area in the second stage of labor significantly correlates with an accurate timing of fetal acidemia. Regardless of the cause of the bradycardia, the time for intervention is often short, meaning that any available intervention may be ineffective in preventing acidemia or even injury.
量化分娩第二产程中的胎儿心动过缓，并确定与新生儿酸血症相关的面积阈值。
我们分析了33名单胎妊娠且足月自然分娩、在分娩第二产程出现胎儿心动过缓的女性的产程图。我们回顾性计算了分娩前最后60分钟内胎儿心动过缓面积，上限为90次/分钟，并将该面积与新生儿pH值相关联。通过回归线研究确定胎儿健康与窘迫之间的临界阈值。设定显著性水平为p < 0.05。
心动过缓面积与新生儿pH值之间的线性相关性表明，心动过缓面积增加与pH值显著降低相关。提示严重酸血症的面积阈值为≥12.72平方厘米（Pearson相关系数r = -0.76，p < 0.002）。该检测的诊断准确性为73%。阳性预测值（PPV） = 78.5%，阴性预测值（NPV） = 68.4%。以此临界值计算，当胎儿心率（FHR）为80次/分钟时，酸血症发生时间为25分钟；FHR为70次/分钟时为13分钟；FHR为60次/分钟时为8分钟；FHR为50次/分钟时为6分钟；FHR为40次/分钟时为5分钟。
分娩第二产程中的心动过缓面积与胎儿酸血症的准确发生时间显著相关。无论心动过缓的原因如何，干预时间往往很短，这意味着任何可用的干预措施可能都无法有效预防酸血症甚至损伤。
