Accuracy of non-invasive methods for assessing the progress of labor in the first stage: a systematic review and meta-analysis

Abstract

Background The World Health Organization in recent years has emphasized reducing the possibility of unnecessary interventions in natural childbirth, but little is known about the accuracy of non-invasive methods when assessing the progress of labor. This paper presents a literature review to assess strategies that support non-invasive methods for labor during the first stage. It evaluates the available evidence to provide the most suitable assessments and predictions that objectively identify the progress of low-risk labor during the first stage of labor. Methods A search for relevant literature was conducted using the electronic databases of PubMed, CINAHL, Web of Sciences, the Cochrane Library, Scopus, Medline (OVID), and CEPS, with publications up to November 2021. Records were screened against pre-specified inclusion/exclusion criteria and the potential papers from Google Scholar were examined to identify additional papers that may have been missed. The Quality Assessment of Diagnostic Accuracy Studies-2 (QUADAS-2) tool was used to appraise the methodological quality of the included studies. The certainty of the evidence was assessed using the Grading of Recommendations Assessment, Development, and Evaluation (GRADE) approach. Two independent investigators extracted the review’s characteristics, and discrepancies were resolved by consensus. This review calculated individual and pooled sensitivity, specificity, and positive predictive values, which were exported to STATA (version 14; Stata Corp., College Station, TX) to represent the performance of diagnostic testing. Results Our search returned 2283 reports of which 13 fulfilled the inclusion criteria, accounting for 2594 women. The subjects were divided into groups according to the diagnostic tests used to assess the progress of their labor, including appearance assessment and sonographic imaging parameters (head perineum distance, HPD; angle of progression, AOP, and other parameters). HPD pooled sensitivity was 0.74 (0.65–0.82), and specificity was 0.77 (0.69–0.84). The pooled diagnostic odds ratio (DOR) was 8.21 (4.67–14.41) and 10.34 (5.02–21.27), respectively. The results of subgroup analysis showed that the summary sensitivity and specificity were of medium accuracy overall. The quality of evidence as assessed with GRADE was low. Conclusion Vaginal examination is an intrinsic element in the use of the partogram, while transperineal ultrasound can also be used as an auxiliary tool. However, the presence of publication bias within the parameters of ultrasound indicates that the diagnostic performance may be overestimated. Thus, randomized controlled trials or large-scale prospective cohort studies are necessary.

Current status of the position on labor progress prediction for contemporary pregnant women using Friedman curves: An updated review

“…30 A systematic review conducted by Pan et al showed that an OSA > 100 to 126 can predict normal vaginal delivery, but <126 has significantly longer first and second stages of labor and a higher rate of requiring cesarean section. 46 HPD data can be used to predict the engaged fetal head, assess labor progress, and predict the mode of delivery. The AOP data can be used to evaluate labor progress and predict the mode of delivery, with an AOP of 93-120 indicating a high likelihood of normal labor progression with a sensitivity of 52%-92%.…”

Methods to reduce the number of vaginal examinations in labour progress assessment so as to support normality at childbirth

“…Over the years, it has become a matter of debate whether a vaginal examination is the most appropriate method to evaluate labour progression, since it is an invasive procedure associated with pain, embarrassment, potential infection, and possible chorioamnionitis [ 7 ]. Moreover, there is inconsistency in examinations with a report that two different clinicians differed in cervical dilatation measurements by 2 cm or more in 11% of occasions [ 1 ].…”

“…Another study showed that the mean number of vaginal examinations was three when the average labour duration was 8 h, but most importantly, the maximum number of examinations was 11 in some cases [ 9 ]. For these reasons and in conjunction with the current interest worldwide to support normality at childbirth, there is an attempt in the literature to identify and re-introduce in clinical practice alternative and less intrusive means of labour progress assessment [ 6 , 7 ].…”

“…There are several methods proposed in the literature either as an alternative or as an adjunct to vaginal examination. These include assessing the frequency and intensity of uterine contractions as well as fetal head descent by abdominal palpation, and identifying changes in maternal behaviour and vocalisations especially in the second stage of labour [ 7 ]. As labour advances, it has been suggested that women focus inwards to cope with the intensity of the uterine contractions, vocal changes may be noticed, and the women may appear flushed [ 12 ].…”

“…These report that the use of intrapartum ultrasound is easy, simple, and non-invasive and can serve as an adjunct to correlate alongside findings of a digital vaginal examination. A systematic review in 2022 reported that the sonographic assessment of various fetopelvic parameters to predict labour progress has been proposed as the new gold standard, but more research work needs to be done before this is established [ 7 ].…”