A Postural Approach to the Pelvic Diameters of Obstetrics: The Dynamic External Pelvimetry Test

Do all patients with history of pelvic ring injuries need a cesarean section? - A survey of orthopaedic and obstetric providers

OBJECTIVE(S)

The recommended mode of delivery following pelvic ring fractures with surgical fixation is unclear. The objective of this study was to assess expert opinions from orthopaedic surgeons and obstetrician gynecologists on their recommended delivery recommendations for pregnant individuals with a history of pelvic ring injury, and to see if there was any difference in recommendations between the two specialties, and what factors influenced recommendations.

STUDY DESIGN

An electronic, web-based survey was administered to a convenience sample of orthopaedic surgeons and obstetrician gynecologists, via advertisement to members of the Orthopaedic Trauma Association (OTA), the Society for Maternal Fetal Medicine, and querying obstetrician gynecologists practicing within the Military Health System. The survey was administered from November 2021 to December 2022. A two-proportion z-test, Chi-square or Fisher's Exact Test, and descriptive statistics were used to analyze data.

RESULTS

Survey respondents included 44 orthopaedic surgeons and 37 obstetricians. A total of 74 % obstetricians would recommend a trial of labor with hardware in place, while orthopaedic surgeon's recommendations varied based on the type of fixation. Forty four, 100 % of orthopaedic surgeons, recommended trial of labor if non-operative pelvic injury or unilateral posterior fixation only, 88 % recommended trial of labor if bilateral posterior fixation only, and 47.7 % for anterior trans-symphyseal plating only, 50 % for unilateral posterior and trans-symphyseal plating, and 43.2 % for bilateral posterior fixation with trans-symphyseal plating.

CONCLUSIONS

The results of these surveys demonstrate the lack of consensus as to the most appropriate birth plan for patients with a history of pelvic ring injuries. Vaginal delivery following pelvic ring fracture and fixation is possible, yet these patients are significantly more likely to undergo cesarean section than the general population. As such, we recommend that women who become pregnant after operative treatment of a pelvic ring injury develop an in-depth birthing plan with their obstetrician to determine the best course.

Perinatal Outcomes and Level of Labour Difficulty in Deliveries with Right and Left Foetal Position-A Preliminary Study

BACKGROUND

Many studies have shown the negative influence of the foetus's occiput posterior position during birth on the final perinatal outcome. This study aims to add to the discussion on the impact of foetus positioning on the course of labour and subjective assessment of the level of labour difficulty.

METHODS

The cross-sectional study took place from February 2020 to September 2021, and consisted of filling out observation forms and the assessment by the midwives and women of the level of labour difficulty. This study is based on the observation of 152 labours in low-risk women.

FINDINGS

When compared to left foetal positioning, labours in which the foetus was in the right position were longer and more frequently failed to progress (in 11.3% vs. 37.5%), and epidural was more frequently administrated (in 30.4% vs. 52.7%). Both women and midwives subjectively evaluated deliveries with a foetus in the right position as more difficult.

CONCLUSIONS

The right positioning of the foetus was related to greater labour difficulty and worse perinatal outcomes. The position of the foetus' head in relation to the pelvis should be considered as an indicator of the difficulty of labour and a support plan for the woman should be offered accordingly.

Fostering childbirth education on upright positions and mobility during labor in nulliparous women

BACKGROUND

Upright labor positions and movement during labor have a positive effect on childbirth, yet the predominant labor positions are still horizontal. Therefore, it is important to explore how it is possible to improve childbirth education, particularly its instructional design, to strengthen women's self-efficacy toward the use of upright positions and mobility during labor. The aim of the study was to evaluate the impact of an instructional approach based on a cognitive engagement ICAP (Interactive, Constructive, Active, Passive) framework on the development of knowledge, attitudes, and self-efficacy expectations toward upright positions and mobility during labor.

METHODS

A prospective quasi-experimental study was conducted among nulliparous women from the ultra-orthodox Jewish community (n = 74). While the control group (n = 34) participated in routine childbirth education, the intervention group (n = 36) learned with childbirth education that included interactive and constructive cognitive engagement activities. Participants in both groups completed a set of questionnaires regarding knowledge, attitudes, and self-efficacy.

RESULTS

The post-test analysis revealed that women in the intervention group compared to the control group gained significantly higher knowledge scores (p < 0.05), more positive attitudes (p < 0.001), and stronger self-efficacy expectations toward upright positions and mobility during labor (p < 0.01).

CONCLUSIONS

The findings suggest that by fostering women's cognitive engagement levels during childbirth education toward the interactive and constructive modes of the ICAP framework, women's self-efficacy to move during labor and to use upright positions can be induced. These results can serve as a foundation to improve the overall effectiveness of childbirth instruction.

TRIAL REGISTRATION

The study was registered retrospectively.

Evaluating the effects of maternal positions in childbirth: An overview of Cochrane Systematic Reviews

INTRODUCTION

The purpose of this study is to conduct an overview of Cochrane systematic reviews (SRs) evaluating the effects of maternal positions in childbirth in order to compile existing evidence for relevant research questions that have been addressed by more than one review, to provide a succinct summary of the up-to-date evidence and to identify areas for future research.

METHODS

An electronic search was conducted in the Cochrane database. Two primary outcomes were the duration of labor and birth, and operative birth. The quality of included reviews was assessed using the AMSTAR criteria, and the quality of the evidence was rated using the GRADE criteria.

RESULTS

We included 3 Cochrane SRs. There was a significant mean difference (MD) found in the duration of the first stage by 1 hour and 22 minutes (MD= -1.21; 95% CI: -2.35 – -0.07, I²=94%) and reduction in caesarean section rates (RR=0.71; 95% CI: 0.54–0.94, I²=0%) in the upright birth position group compared with the horizontal. Also, there was a statistically significant difference in the duration (minutes) of the second stage of labor (MD= -6.16; 95% CI: -9.74 – -2.59, I²=91%) and a reduction in assisted vaginal birth rates (RR=0.75, 95% CI: 0.66–0.86, I²=29%) in the upright group compared with the horizontal without epidural analgesia. The quality of evidence within the reviews was very low to moderate.

CONCLUSIONS

There is currently a limited body of evidence to clearly assess the benefits and risks of assuming upright positions during childbirth. The overview highlights the need for high-quality research studies, involving better definition and comprehensive assessment of the effects of squatting during childbirth.

Can the Dynamic External Pelvimetry Test in Late Pregnancy Reveal Obstructed and Prolonged Labor? Results From a Pilot Study

Background The size and mobility of the maternal pelvic space are fundamental factors in successful childbirth and can allow operators to screen for dystocia. This pilot study including a group of 70 pregnant women aimed to test whether the external dynamic pelvimetry test can be used to predict the likelihood of obstructed labor. Methodology The study cohort consisted of 70 pregnant women in their third trimester. The cohort was divided retrospectively into an obstructed labor group and a control group. Obstructed labor was defined using the following obstetric outcomes: augmentation with oxytocin from the first phase of the dilating period, Kristeller's maneuvers, vacuum extractor (kiwi), forceps, and the cesarean section following the onset of labor. Results The measurements obtained for the longitudinal hemi-diameter of Michaelis, the inter-tuberous diameter, and the base of the Trillat's triangle were statistically significant in every position. The difference in the measurements of the transverse diameter of Michaelis between standing and hands-and-knees position and the difference in the sizes of the bi-cristal diameter between hands-and-knees and squatting position were statistically significant. Conclusions Dimension and biomechanical properties of the pelvic tissue and spaces influence the evolutionary childbirth process. After clinical confirmation on a large population, hypomobility of specified external pelvic diameters measured in shifting positions can become a screening tool to detect the contracted pelvis and prevent damage caused by dystocia and prolonged labor in women and newborns.

Dynamic External Pelvimetry Test in Third Trimester Pregnant Women: Shifting Positions Affect Pelvic Biomechanics and Create More Room in Obstetric Diameters

Dystocia in labor is still a clinical challenge. The "contracted pelvis" is the absence of pelvic mobility, which leads to fetal-pelvic disproportion, obstructed labor, and operative delivery. Maternal pelvis biomechanics studies by high technological techniques have shown that maternal shifting positions during pregnancy and labor can create more room in the pelvis for safe delivery. The external and internal pelvic diameters are related. The present study aims to evaluate the external obstetric pelvic diameters in shifting positions using a clinical technique suitable for daily practice in every clinical setting: the dynamic external pelvimetry test (DEP test). Seventy pregnant women were recruited, and the obstetric external pelvic diameters were measured, moving the position from kneeling standing to "hands-and-knees" to kneeling squat position. Results showed modification of the pelvic diameters in shifting position: the transverse and longitudinal diameters of Michaelis sacral area, the inter-tuberosities diameter, the bi-trochanters diameter, and the external conjugate widened; the bi-crestal iliac diameter, the bi-spinous iliac diameter, and the base of the Trillat's triangle decreased. The test showed good reproducibility and reliability. Linear correlations were found between diameters and between the range of motion of the diameters. The maternal pelvis is confirmed to modify the diameters changing its tridimensional shape. The pelvic inlet edge's inclination is inferred to be modified, facilitating the fetal descend. The pelvic outlet enlarged the transverse diameter, facilitating birth. The DEP test estimates the pelvic diameters' modification with postural changes, as magnetic resonance (MR) and computational biomechanics studies have demonstrated.

Estimating the Mobility of the Michaelis Sacral Rhombus in Pregnant Women

Pelvic mobility is the cornerstone of an adequate birth canal for safe childbirth, and midwives invite pregnant women to assume loading positions to facilitate delivery. Biomechanics asserts that pelvic space changes in shifting positions from erect to the squat position. The current standard practice in obstetrics and osteopathy provides a qualitative observational assessment of the dimension of Michaelis sacral rhombus in shifting positions; a previous report presented a clinical method and instrument to estimate the pelvic range of motion through finger contact on bone landmarks. The present study aims to match the measurement of the diameters of the sacral area of Michaelis from skin marks with the amount from bone landmarks. Methods estimate the sacral area from 100 pregnant women in the late trimester, considering the dimension of the diameters, the range of motion, and the patterns of mobility. Differences resulted in the methods: measuring the skin marks in shifting positions revealed a not significant difference between starting position and squat position. The measurements through the finger contact on the bone landmarks seem to be adequate to estimate pelvic mobility fulfilling the expectation from biomechanics literature.