Public Release: 

STAN as an adjunct to intrapartum fetal heart rate monitoring did not improve perinatal outcomes

Society for Maternal-Fetal Medicine

SAN DIEGO (Feb. 2, 2015)--In a study to be presented on Feb. 5 in plenary session at 8 a.m. PST, at the Society for Maternal-Fetal Medicine's annual meeting, The Pregnancy Meeting™, in San Diego, researchers will report that analysis of the ST segment on the fetal electrocardiogram (STAN) as an adjunct to conventional intrapartum electronic fetal heart rate monitoring did not improve perinatal outcomes or decrease operative deliveries in hospitals in the United States. STAN is a recently developed technology that is used in Europe as an adjunct to conventional intrapartum fetal heart rate monitoring, and was approved by the FDA for use in the US, mostly based on results of studies in Europe and one small study in the US.

The study, titled Fetal ECG Analysis of the ST Segment as an Adjunct to Intrapartum Fetal Heart Rate Monitoring; A Randomized Clinical Trial, sought to determine whether monitoring the fetal electrocardiogram in addition to the usual monitoring during labor improves perinatal outcomes and decreases operative deliveries in 26 hospitals within the US. Researchers at centers affiliated with the Eunice Kennedy Shriver National Institute of Child Health and Human Development Maternal-Fetal Medicine Units Network enrolled 11,108 women in labor who were randomized to monitoring with STAN plus conventional monitoring versus conventional monitoring only. Unlike what was found in Europe, addition of STAN to the conventional monitoring did not improve outcomes of the baby nor did it decrease cesarean deliveries in this study, the largest one to date.

The study highlights the need for caution when extrapolating results from studies outside the U.S. and the importance of testing medical interventions and technologies in the settings and populations where they will be applied. Introduction of medical interventions and technologies without appropriate testing can result in increased cost and potentially worsening of outcomes.

"Fortunately, the rates of adverse neonatal outcomes were overall low, stated George Saade, M.D., one of the researchers on the study who will be presenting the findings at the SMFM annual meeting." With the high rates of cesarean deliveries in the US, largely due to unreliable methods of monitoring during labor, it is essential that we continue research to find better ways to assess the well being of the baby."

The study is the largest randomized trial of its kind in the US, and would not have been possible without the support of the Eunice Kennedy Shriver National Institute of Child Health and Human Development. The need for large numbers of patients, multiple sites, and several years are reminders of the challenges faced by researchers striving to improve neonatal outcomes and decrease cesarean deliveries. The quest for better methods to monitor women in labor and for better approaches to decreasing cesarean rates remains on. It is imperative that we increase funding in this area of research.

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A copy of the abstract is available at http://www.smfmnewsroom.org and below. For interviews please contact Vicki Bendure at Vicki@bendurepr.com 202-374-9259 (cell).

The Society for Maternal-Fetal Medicine (est. 1977) is the premiere membership organization for obstetricians/gynecologists who have additional formal education and training in maternal-fetal medicine. The society is devoted to reducing high-risk pregnancy complications by sharing expertise through continuing education to its 2,000 members on the latest pregnancy assessment and treatment methods. It also serves as an advocate for improving public policy, and expanding research funding and opportunities for maternal-fetal medicine. The group hosts an annual meeting in which groundbreaking new ideas and research in the area of maternal-fetal medicine are shared and discussed. For more information visit www.smfm.org.

Abstract 1: Fetal ECG Analysis of the ST Segment as an Adjunct to Intrapartum Fetal Heart Rate Monitoring; A Randomized Clinical Trial.

Author: George Saade. M.D. for the Eunice Kennedy Shriver National Institute of Child Health and Human Development Maternal-Fetal Medicine Units Network, Bethesda, Md.

Objective: Fetal ECG analysis of the ST segment (STAN) is used in Europe as an adjunct to conventional intrapartum fetal heart rate (FHR) monitoring. We sought to determine whether STAN improves perinatal outcomes and decreases operative deliveries at 26 hospitals within the United States.

Study Design: Women attempting vaginal singleton delivery at ≥ 36w 1d with cervical dilation 2-7 cm were randomized to an "open" or "masked" STAN FHR monitor (Neoventa Medical). Masked STAN functioned as a normal FHR monitor, while open STAN displayed additional information that is used in cases with uncertain FHR patterns. All care providers were trained and certified per FDA approved management guidelines for STAN. Before the trial, all sites completed a training pilot study (total 1,527 women). Each delivery was overseen by authorized STAN providers. The primary outcome was a composite of at least one of: intrapartum fetal death, neonatal death, Apgar score ≤ 3 at 5 minutes, neonatal seizure, cord artery pH ≤ 7.05 plus base deficit ≥ 12 mmol/L, intubation for ventilation at delivery, and neonatal encephalopathy. Valid cord artery pH required both artery and vein values confirmed based on a pre-specified algorithm. Secondary outcomes included type of delivery and measures of maternal morbidity. Training, review of selected cases and feedback was ongoing during the trial.

Results: 11,108 were randomized (5,532 open, 5,576 masked). Valid cord gases were available for 96.5%. There were no significant differences in baseline characteristics between the groups. There were no significant differences in the primary or secondary outcomes (Table). There were no differences by subgroups based on parity, type of labor, cervical dilation at entry, or time period of the study (test for interaction, all p>0.05).

Conclusion: Use of STAN as an adjunct to conventional intrapartum electronic fetal heart rate monitoring did not improve perinatal outcomes or decrease operative deliveries in hospitals in the United States.

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