Westerhuis Michelle E M H, Moons Karel G M, van Beek Erik, Bijvoet Saskia M, Drogtrop Addy P, van Geijn Herman P, van Lith Jan M M, Mol Ben W J, Nijhuis Jan G, Oei S Guid, Porath Martina M, Rijnders Robbert J P, Schuitemaker Nico W E, van der Tweel Ingeborg, Visser Gerard H A, Willekes Christine, Kwee Anneke
Department of Obstetrics and Gynaecology, University Medical Center Utrecht, The Netherlands.
BMC Pregnancy Childbirth. 2007 Jul 26;7:13. doi: 10.1186/1471-2393-7-13.
Cardiotocography (CTG) is worldwide the method for fetal surveillance during labour. However, CTG alone shows many false positive test results and without fetal blood sampling (FBS), it results in an increase in operative deliveries without improvement of fetal outcome. FBS requires additional expertise, is invasive and has often to be repeated during labour. Two clinical trials have shown that a combination of CTG and ST-analysis of the fetal electrocardiogram (ECG) reduces the rates of metabolic acidosis and instrumental delivery. However, in both trials FBS was still performed in the ST-analysis arm, and it is therefore still unknown if the observed results were indeed due to the ST-analysis or to the use of FBS in combination with ST-analysis.
METHODS/DESIGN: We aim to evaluate the effectiveness of non-invasive monitoring (CTG + ST-analysis) as compared to normal care (CTG + FBS), in a multicentre randomised clinical trial setting. Secondary aims are: 1) to judge whether ST-analysis of fetal electrocardiogram can significantly decrease frequency of performance of FBS or even replace it; 2) perform a cost analysis to establish the economic impact of the two treatment options. Women in labour with a gestational age > or = 36 weeks and an indication for CTG-monitoring can be included in the trial. Eligible women will be randomised for fetal surveillance with CTG and, if necessary, FBS or CTG combined with ST-analysis of the fetal ECG. The primary outcome of the study is the incidence of serious metabolic acidosis (defined as pH < 7.05 and Bdecf > 12 mmol/L in the umbilical cord artery). Secondary outcome measures are: instrumental delivery, neonatal outcome (Apgar score, admission to a neonatal ward), incidence of performance of FBS in both arms and cost-effectiveness of both monitoring strategies across hospitals. The analysis will follow the intention to treat principle. The incidence of metabolic acidosis will be compared across both groups. Assuming a reduction of metabolic acidosis from 3.5% to 2.1 %, using a two-sided test with an alpha of 0.05 and a power of 0.80, in favour of CTG plus ST-analysis, about 5100 women have to be randomised. Furthermore, the cost-effectiveness of CTG and ST-analysis as compared to CTG and FBS will be studied.
This study will provide data about the use of intrapartum ST-analysis with a strict protocol for performance of FBS to limit its incidence. We aim to clarify to what extent intrapartum ST-analysis can be used without the performance of FBS and in which cases FBS is still needed.
ISRCTN95732366.
在全球范围内，产时胎儿监护的方法是胎心监护（CTG）。然而，仅靠CTG会出现许多假阳性检测结果，而且在不进行胎儿血样采集（FBS）的情况下，会导致手术分娩增加，而胎儿结局并未得到改善。FBS需要额外的专业知识，具有侵入性，并且在分娩过程中常常需要重复进行。两项临床试验表明，CTG与胎儿心电图（ECG）的ST段分析相结合可降低代谢性酸中毒和器械助产的发生率。然而，在这两项试验中，ST段分析组仍进行了FBS，因此，仍不清楚观察到的结果究竟是由于ST段分析，还是由于FBS与ST段分析联合使用所致。
方法/设计：我们旨在通过一项多中心随机临床试验，评估与常规护理（CTG + FBS）相比，无创监测（CTG + ST段分析）的有效性。次要目标包括：1）判断胎儿心电图的ST段分析能否显著降低FBS的执行频率，甚至取代FBS；2）进行成本分析，以确定两种治疗方案的经济影响。孕周≥36周且有CTG监测指征的分娩妇女可纳入该试验。符合条件的妇女将被随机分配接受CTG胎儿监护，必要时进行FBS，或接受CTG与胎儿ECG的ST段分析相结合的监护。该研究的主要结局是严重代谢性酸中毒的发生率（定义为脐动脉血pH < 7.05且碱剩余> 12 mmol/L）。次要结局指标包括：器械助产、新生儿结局（阿氏评分、入住新生儿病房情况）、两组中FBS的执行发生率以及两种监测策略在各医院的成本效益。分析将遵循意向性分析原则。将比较两组代谢性酸中毒的发生率。假设代谢性酸中毒发生率从3.5%降至2.1%，采用双侧检验，α = 0.05，检验效能为0.80，若支持CTG加ST段分析，则约需随机分配5100名妇女。此外，还将研究CTG与ST段分析相比CTG与FBS的成本效益。
本研究将提供关于产时ST段分析使用情况的数据，并采用严格的FBS执行方案以限制其发生率。我们旨在明确产时ST段分析在不进行FBS的情况下能在多大程度上使用，以及在哪些情况下仍需要FBS。
ISRCTN95732366。
