Old way of Fetal Surveillance Better than New Approaches, claims study
Fetal surveillance is routinely offered to patients in labour to reduce the risk of adverse neonatal outcomes, as well as the risk of unnecessary emergency cesarean deliveries and other maternal interventions. In a recent study, researchers have reported that intermittent auscultation outperforms other fetal surveillance methods and improves both neonatal and maternal outcomes. The research has been published in the CMAJ on April 06, 2021.
Monitoring the fetal heart rate to detect intrapartum hypoxia using simple surveillance techniques, such as the Pinard stethoscope, has been practised for decades. Over the last 50 years, several newer surveillance methods have been evaluated, with varied uptake in practice. Cardiotocography (CTG) remains the most common surveillance method used in high-risk pregnancies. Physicians also prefer the combination with other surveillance methods, such as fetal heart electrocardiogram (STAN), fetal scalp pH analysis (FBS) or fetal pulse oximetry (FPO), and with computer-aided decision models (cCTG) to improve its diagnostic value. However, the effects of different methods on the risk of emergency cesarean deliveries remain uncertain. Therefore, Dr Bassel H. Al Wattar and his colleagues conducted a study to evaluate the effectiveness of different types of fetal surveillance.
In this systematic review and network meta-analysis, the researchers searched MEDLINE, Embase and CENTRAL for randomized trials evaluating any intrapartum fetal surveillance method. They included a total of 33 trials (118 863 patients) evaluating intermittent auscultation with Pinard stethoscope/handheld Doppler (IA), cardiotocography (CTG), computerized cardiotocography (cCTG), CTG with fetal scalp lactate (CTG-lactate), CTG with fetal scalp pH analysis (CTG-FBS), CTG with fetal pulse oximetry (FPO-CTG), CTG with fetal heart electrocardiogram (CTG-STAN) and their combinations. They performed a network meta-analysis within a frequentist framework and assessed the quality and network inconsistency of trials. They reported primarily on intrapartum emergency cesarean deliveries and other secondary maternal and neonatal outcomes.
Key findings of the study were:
Upon analysis, the researchers found that intermittent auscultation reduced the risk of emergency cesarean deliveries compared with other types of surveillance, except for STAN-CTG-FBS (RR 1.17)
◊ IA vs CTG: RR 0.83,
◊ IA vs CTG-FBS: RR 0.71,
◊ IA vs CTG-lactate: RR 0.77,
◊ IA vs FPO-CTG: RR 0.75,
◊ IA vs FPO-CTG-FBS: RR 0.81,
◊ cCTG-FBS vs IA: RR 1.21.
- They observed a similar reduction in emergency cesarean deliveries for fetal distress.
- However, they noted that none of the evaluated methods was associated with a reduced risk of neonatal acidemia, neonatal unit admissions, Apgar scores or perinatal death.
The authors concluded, "Compared with other types of fetal surveillance, intermittent auscultation seems to reduce emergency cesarean deliveries in labour without increasing adverse neonatal and maternal outcomes."
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