NEW YORK (Reuters Health) – Analysis of the ST segment on the fetal electrocardiogram combined with conventional cardiotocography during intrapartum monitoring reduces the rate of operative vaginal deliveries but does not reduce the risk of metabolic acidosis in neonates, according to a report in the January issue of Obstetrics & Gynecology.
“Future studies on long-term behavioral and neurological outcomes will hopefully provide some information about long-term cost-effectiveness and can guide the clinicians’ decision on whether fetal ST analysis can add quality during labor in everyday clinical practice,” the authors comment.
Dr. Jeroen H. Becker, at the University Medical Center Utrecht, the Netherlands, and colleagues explain that several randomized trials have looked at the value of the fetal ECG in intrapartum monitoring, and a meta-analysis was reported by the Cochrane Collaboration in 2009. However, since then the largest study of the topic has been published.
The team therefore performed a new meta-analysis to quantify the effects of ST analysis compared with conventional cardiotocography. They identified 81 randomized trials that assigned participants to intrapartum fetal monitoring using either ST-waveform analysis in combination with conventional cardiotocography or conventional cardiotocography alone. Ultimately, five trials involving a total of 15,352 subjects met all inclusion criteria.
The pooled data indicated that ST analysis compared with conventional cardiotocography significantly reduced the need for additional fetal blood sampling (relative risk 0.59), operative vaginal deliveries (RR 0.88) and total operative deliveries (RR 0.94).
However, the reduction in incidence of metabolic acidosis at birth (RR 0.72) was not statistically significant. “Because of the among-study differences in the effect on metabolic acidosis, it is questionable whether metabolic acidosis is the right outcome to investigate,” the researches comment. “However, because the incidence of perinatal death and severe neonatal encephalopathies is extremely low … surrogate outcomes with a higher incidence are necessary for efficient evaluation of methods of intrapartum monitoring.”
There was no difference between the two monitoring strategies in terms of other outcomes such as cesarean delivery or admission to the neonatal ICU, Dr. Becker and colleagues report.
In discussing the results, they point out that “we found no clear evidence of neonatal benefit so far.” To determine whether ST analysis should be used in everyday practice, they suggest, studies of long-term outcomes and cost-effectiveness analyses are needed.
SOURCE:
ST Analysis of the Fetal Electrocardiogram in Intrapartum Fetal Monitoring: A Meta-Analysis
Obstet Gynecol 2012;119:145–54)
