Internal versus external tocodynamometry during induced or augmented labour

First and Second Stage Labor Management: ACOG Clinical Practice Guideline No. 8

PURPOSE

The purpose of this document is to define labor and labor arrest and provide recommendations for the management of dystocia in the first and second stage of labor and labor arrest.

TARGET POPULATION

Pregnant individuals in the first or second stage of labor.

METHODS

This guideline was developed using an a priori protocol in conjunction with a writing team consisting of one maternal-fetal medicine subspecialist appointed by the ACOG Committee on Clinical Practice Guidelines-Obstetrics and two external subject matter experts. ACOG medical librarians completed a comprehensive literature search for primary literature within Cochrane Library, Cochrane Collaboration Registry of Controlled Trials, EMBASE, PubMed, and MEDLINE. Studies that moved forward to the full-text screening stage were assessed by the writing team based on standardized inclusion and exclusion criteria. Included studies underwent quality assessment, and a modified GRADE (Grading of Recommendations Assessment, Development, and Evaluation) evidence-to-decision framework was applied to interpret and translate the evidence into recommendation statements.

RECOMMENDATIONS

This Clinical Practice Guideline includes definitions of labor and labor arrest, along with recommendations for the management of dystocia in the first and second stages of labor and labor arrest. Recommendations are classified by strength and evidence quality. Ungraded Good Practice Points are included to provide guidance when a formal recommendation could not be made because of inadequate or nonexistent evidence.

Qualitative assessment of interpretability and observer agreement of three uterine monitoring techniques

OBJECTIVE

The aim of this research was to assess the quality and inter- and intra-observer agreement of tracings obtained by three different techniques for uterine contraction monitoring: the external tocodynamometer (TOCO), the intrauterine pressure catheter (IUPC) and a recently introduced method based on electrohysterography (EHG).

STUDY DESIGN

We included 150 uterine activity registrations from a previous prospective observational study (W3 study), conducted at Máxima Medical Centre in Veldhoven, the Netherlands. Term singleton pregnant women were simultaneously monitored with TOCO, IUPC and EHG during labor. Six clinicians, blinded to the source (TOCO, IUPC, or EHG) and subject, evaluated all tracings that were subsequently presented in random order. They annotated contractions and assigned each tracing a score for interpretability of 2 (good), 1 (moderate) or 0 (poor). To evaluate inter-observer agreement, we calculated kappa values for the qualitative assessment, and intraclass correlation coefficients (ICC) for the number of contractions annotated by clinicians. Four clinicians repeated this procedure to evaluate intra-observer agreement.

RESULTS

IUPC tracings received the highest quality rating, with a mean score of 1.95, followed by a mean score of 1.60 for EHG and 0.80 for TOCO (p < 0.05). Mean weighted kappa values were 0.63 for TOCO and 0.45 for EHG. The average number of contractions that was picked up by clinicians was 59.8 for the intrauterine pressure catheter, 49.8 for EHG and 26.4 for TOCO. The ICC of the intrauterine pressure catheter was significantly higher than the external methods, regarding both inter- and intra-observer agreement (0.98 and 0.99 respectively).

CONCLUSION

IUPC recordings scored best regarding quality, inter- and intra-observer agreement. However, due to safety issues, in many countries this technique is not used anymore. The quality of TOCO was rated as poor and many contractions were missed as compared to the gold standard. From a clinical interpretational point of view, EHG is favorable to TOCO. EHG recordings were assigned higher quality scores, but with less agreement between clinicians. An explanation could be that EHG is a relatively new technique, while IUPC and the TOCO are being used for decades. Building experience with EHG (training) is therefore recommended.

Uterine Monitoring Techniques from Patients' and Users' Perspectives

Objective  To evaluate preferences from patients and users on 3 uterine monitoring techniques, during labor. Study Design  Women in term labor were simultaneously monitored with the intrauterine pressure catheter, the external tocodynamometer, and the electrohysterograph. Postpartum, these women filled out a questionnaire evaluating their preferences and important aspects. Nurses completed a questionnaire evaluating users' preferences. Results  Of all 52 participating women, 80.8% preferred the electrohysterograph, 17.3% the intrauterine pressure catheter and 1.9% the external tocodynamometer. For these women, the electrohysterograph scored best regarding application and presence during labor ( p  < 0.001). Most important aspects were "least likely to harm" and "least discomfort". Of 57 nurses, 40.4% preferred the electrohysterograph, 35.1% the external tocodynamometer, and 24.6% had no preference, or replied that their preference is subject to situation and patient. Conclusion  Patients prefer the electrohysterograph over the external tocodynamometer and the intrauterine pressure catheter, while healthcare providers report ambiguous results.