Head-perineum Distance Research Articles

A machine learning model to predict spontaneous vaginal delivery failure for term nulliparous women: An observational study.

This study aims to construct and evaluate a model to predict spontaneous vaginal delivery (SVD) failure in term nulliparous women based on machine learning algorithms. In this retrospective observational study, data on nulliparous women without contraindications for vaginal delivery with a singleton pregnancy ≥37 weeks and before the onset of labor from September 2020 to September 2021 were divided into a training set and a temporal validation set. Transperineal ultrasound was performed to collect angle of progression, head-perineum distance, subpubic arch angle, and their levator hiatal dimensions. The cervical length was measured via transvaginal ultrasound. The delivery methods were later recorded. Through LASSO regression analysis, indicators that can affect SVD failure were selected. Seven common machine learning algorithms were selected for model training, and the optimal algorithm was selected based on the area under the curve (AUC) to evaluate the effectiveness of the validation model. Four indicators related to SVD failure were identified through LASSO regression screening: angle of progression, cervical length, subpubic arch angle, and estimated fetal weight. The Gaussian NB algorithm was found to yield the highest AUC (0.82, 95% confidence interval [CI] 0.65-0.98) during model training, and hence it was chosen for verification with the temporal validation set, in which an AUC of 0.79 (95% CI 0.64-0.95) was obtained with accuracy, sensitivity, and specificity rates of 80.9%, 72.7%, and 75.0%, respectively. The Gaussian NB model showed good predictive effect, proving its potential as a clinical reference for predicting SVD failure of term nulliparous women before actual delivery.

Impact of body mass index on sonographic measurement of head perineum distance before operative vaginal delivery.

To evaluate the impact of body mass index (BMI) on sonographic measurement of head perineum distance (HPD) before operative vaginal delivery (OVD). This was a single-center retrospective cohort study (Lille, France) conducted from March 1, 2019 to October 31, 2020 including all singleton and OVD. HPD measurement was systematically performed without and with compression on the perineum soft tissues. The level of station was defined by vaginal examination and three maternal BMI groups were defined (normal BMI [<24.9 kg/m2] vs overweight [25-29.9 kg/m2] vs obese [≥30 kg/m2]). HPD measures were compared between BMI groups and compression, in distinct level of station, using a two-factor analysis of variance including BMI groups, the compression, and the interaction term BMI group compression. A total of 775 women were included: 488 with normal BMI, 181 overweight patients and 106 obese patients. The measurement of HPD before OVD without and with compression on the soft tissues was significantly different between the BMI groups only in the lower part, particularly between normal BMI and obese patients (mean difference (95% CI): 6.6 mm (4.0 to 9.2) without compression; 3.8 (1.1 to 6.4) with compression). The values of HPD without and with compression on the soft tissues on the maternal perineum were different according to the maternal BMI concerning lower part station. Thus, it seems important to define thresholds of HPD measures corresponding to each head station levels according to maternal BMI.

Ultrasound assessment of fetal head-perineum distance and cervical length to predict the success of labour induction

Ultrasound assessment of fetal head-perineum distance and cervical length to predict the success of labour induction

Assessment of different sonographic cervical measures to predict labor induction outcomes: a systematic review and meta-analysis.

Induction of labor (IOL) is a common obstetric approach to start or encourage uterine contractions to achieve a vaginal birth. It is recommended when continuing the pregnancy may be more dangerous for the mother or baby. Different ultrasonographic measures, such as cervical length, have been investigated as possible predictors of the outcomes of IOL. This meta-analysis aimed to assess the accuracy of ultrasound measurements in anticipating successful IOL. The study conducted a thorough search on three databases (PubMed, Scopus, and Web of Science) until 04 March 2023, to find clinical studies published in English that reported different sonographic cervical measures and their ability to predict IOL outcomes. The chosen studies were stratified based on the type of indicator reported, and a meta-analysis was conducted to determine the best indicator for both successful and failed induction. The risk of bias and concerns about the applicability of the included studies was evaluated using the Quality Assessment of Diagnostic Accuracy Studies-2 (QUADAS-2) method. This study analyzed 57 studies with 9,338 patients. Cervical length is moderately effective in predicting successful IOL, with pooled sensitivity (SN) and specificity (SP) of 0.67 and 0.70, respectively. However, cervical length had a pooled SN and SP of 0.70 and 0.61 for predicting failed IOL. The posterior cervical angle was found to have a higher pooled SN and SP of 0.79 and 0.73 for predicting successful IOL. Fetal head-perineum distance demonstrated moderate accuracy with a pooled SN, SP, positive likelihood ratio, negative likelihood ratio, diagnostic odds ratio, and area under the curve of 0.58, 0.66, 1.95, 0.36, 5.33, and 0.9992, respectively, for predicting successful IOL. Fetal head-perineum distance was the most effective predictor for successful IOL compared to cervical length, which only had a moderate predictive ability. Shortening of cervical length was not a useful indicator for successful IOL. On the other hand, the posterior cervical angle was the most reliable factor for predicting failed induction. The study's findings can aid in developing more effective management strategies for IOL.

Intrapartum ultrasound and mother acceptance: A study with informed consent and questionnaire

IntroductionIntrapartum ultrasound (IU) is used in the delivery ward; even if IU monitors the labouring women, it could be perceived as a discomfort and even as an“ obstetric violence”, because it is a young technique, not often well "accepted". A group of clinicians aimed at obtain an informed consent from patients, prior to perform a translabial ultrasound (TU). The aim of this study was to evaluate the acceptance of both translabial and transabdominal IU. MethodsIn this study, performed at the University Hospital of Bari (Unit of Obstetrics and Gynecology), were enrolled 103 patients in the first or second stage of labor in singleton cephalic presentation. A statistical frequency and an association analysis were performed. As a significant result, we consider the peace of mind/satisfaction and the” obstetric violence”. IU was performed both transabdominal and translabial to determine the presentation, head positions, angle of progression and head perineum distance. During the first and second stage of labor, the ASIUG questionnaires (Apulia study intrapartum ultrasonography group) were administered. Results74 (71, 84%) patients underwent IU and 29 had a vaginal examination (28, 15%). Significant less “violence” has been experienced with a IU (73 out 74/98, 65%) and only one person (1 /1, 35%) recorded that. On the contrary, 10 patients (10/29) perceived that “violence” (34, 48%) while 19 (65, 52%) did not respond on a similar way, after a vaginal examination (VE). More patients felt satisfaction (71 out 74/95, 95%) with the use of IU and only 3 (3/4, 05%) felt unease. A different picture was evident in the vaginal examination group. Only 17 patients (17 out 29/58, 62%) felt comfort while 12 (41, 38%) felt unease. ConclusionsIn our study, IU use is well accepted by most of patients, because it could reassure women about their fetal condition. Moreover, they can see the fetus on the screen, while the obstetrician is performing the US and this is important for a visual feedback, in comparison with the classical VE.

Does transperineal ultrasound predict the risk of perineal trauma in women with term pregnancy? A prospective observational study.

This study was conducted to evaluate the prevalence of perineal trauma during childbirth and to assess the correlations of the pelvic floor dimensions and fetal head station with obstetric trauma in a prospectively recruited cohort of women. The study included women with a gestational age of at least 37 weeks, who were carrying a single fetus in a cephalic presentation. Transperineal ultrasound (TPU) was performed prior to the onset of labor or labor induction. The purpose was to measure the anteroposterior diameter (APD) of the levator ani muscle (LAM) and the angle of progression, at both rest and maximum Valsalva maneuver. The head-perineum distance was assessed only at rest. A total of 296 women were included. Of the 253 women who delivered vaginally, 19% (48/253) experienced no perineal trauma, 18.2% (46/253) received an episiotomy during childbirth, 34.4% (87/253) sustained a first-degree laceration, 25.3% (64/253) had a second-degree laceration, and 3.2% had a third- or fourth-degree laceration (8/253). Women with episiotomy had a significantly shorter median APD under Valsalva than women without perineal trauma. Furthermore, women with LAM coactivation (identified by a negative difference between the APD at Valsalva and the APD at rest) were approximately three times more likely to undergo an operative vaginal delivery and over five times more likely to sustain a third- or fourth-degree tear during childbirth than women who exhibited normal relaxation of the LAM during the Valsalva maneuver. TPU may predict the risk of perineal trauma in women with term pregnancy during childbirth.

Comparison of Transperineal Ultrasound Cervical Length and Fetal Head- Perineum Distance Measurements with a Simplified Bishop Score in Predicting Induction of Labor Outcome: What is new?

Context: The goal of Induction of labor (IOL) is to achieve vaginal delivery and reduce cesarean section. The Bishop score (BS) is the gold standard method to assess cervical status, but it is not flawless, leading to unnecessary interventions. Transperineal ultrasound measurements have been compared with the BS in predicting successful IOL. Yet the results are inconsistent. Aim: This study aimed to compare transperineal ultrasound measurements and a simplified BS in predicting IOL outcomes at Ahmadu Bello University Teaching Hospital (ABUTH) Zaria. Settings and Design: This was a cross-sectional comparative observational study conducted at the labor wards of ABUTH. Materials and Methods: It was conducted among women for IOL at 37–42 weeks between June 2019 and February 2020. Ninety-Seven women were recruited. Each woman, had a transperineal ultrasound cervical length (TPUS-CL) and fetal head perineum distance (FHPD) measured. This was followed by a simplified BS assessment. Statistical Analysis Used: Relevant Data obtained was entered and analyzed using SPSS version 23. The significance level was considered at P &lt; 0.05. Results: The diagnostic accuracy of TPUS-CL (area under the curve (AUC) =0.604, P = 0.084) was better than the simplified BS (AUC = 0.551, P = 0.402). FHPD (P = 0.067, CI = 0.983–1.661) was superior to fetal station (P = 0.832, CI = 0.599–1.890) in predicting the outcome of IOL. The favorable cut-off values for TPUS-CL, FHPD, and BS in our study were ≤ 3 cm, ≤5 cm, and 5 respectively. It demonstrated that TPUS-CL (P = 0.005, AUC = O.750) and FHPD (P = 0.017, AUC = 0.711) are better than simplified BS in predicting success among Primigravidas. Conclusion: TPUS-CL and FHPD measurements are better than the simplified BS in predicting IOL outcome in primigravidae.

Intrapartum ultrasound in maternal lateral versus semi-recumbent posture. A repeated measures study

ObjectiveThis study aimed to assess whether intrapartum ultrasound (ITU) measurements in maternal lateral posture are superimposable to ITU measurements in semi-recumbent position. Study designA single-center, repeated measures design was used. Women in the second stage of labor were randomized to ITU first in semi-recumbent followed by ITU in side-lying posture without and with contraction, or inversely.The angle of progression (AOP) and the head-perineum distance (HPD) between contractions (AOP1 and HPD1) and with contraction (AOP2 and HPD2) were measured in each maternal posture. The differences between AOP1 and AOP2 (dAOP), and between HPD1 and HPD2 (dHPD) were calculated. Results and conclusionsForty-two women participated in the study. A generalized estimating equation model showed that AOP1 (-3.00°; 95 % CI −5.77 to −0.23; p = 0.03) and AOP2 (-4.14°; 95 % CI −7.20 to −1.08; p = 0.008) were lower in semi-recumbent compared to maternal lateral posture. HPD1 (+1.43 mm; 95 % CI 0.05–2.81; p = 0.042) and HPD2 (+1.53 mm; 95 % CI 0.17–2.89; p = 0.03) were higher in semi-recumbent position.Differences in the ITU measurements in maternal lateral posture compared to semi-recumbent position are small. Monitoring the second stage of labor with ITU in lateral maternal posture is possible.

Assessment of the angle of progression and head-perineum distance in the prediction of type of delivery and duration of second stage of labor using intrapartum transperineal ultrasonography

Background: Each pregnancy's straightforward goal is to deliver a healthy baby to a healthy mother. Prolonged second stages of labour have been linked to poor mother and neonatal outcomes. The gold standard for diagnosing head descent clinically is still a digital transvaginal examination. Head station is based on the relationship between the ischial spine and the leading edge of the foetal head in the maternal pelvis. The intrapartum transperineal ultrasonography is a safe method for determining the position of the foetal head and for anticipating the course of the delivery. It is very useful in analyzing phenomena connected to the transit of the foetus through the birth canal.Aims: This study's objective is to assess the effectiveness of intrapartum transperineal ultrasound in predicting the kind of birth and length of the second stage of labour by assessing parameters for the Angel of Progression and Head Perineum Distance.Patients and Methods: Cross-sectional prospective research is the study's design. At Tanta University Hospitals' Department of Obstetrics inpatient ward, 65 primigravida women participated in the study. commenced in August 2021 and concluded in August 2022.Results: According to our findings, there was a positive highly statistically significant correlation between AOP and vaginal delivery patients compared to CS delivery patients, while there was a negative highly statistically significant correlation between HPD and vaginal delivery patients compared to CS delivery patients. A positive highly statistically significant association was found between the length of the second stage and the HPD, while a negative highly statistically significant correlation was found between the length of the second stage and the angle of progression.Conclusion: Intrapartum ultrasound has been used to measure a number of characteristics, including the angle of progression (AOP) and head-perineum distance (HPD). The manner of delivery and length of pushing can be predicted with the help of an ultrasound conducted at the start of the active second stage of labour.

Reliability and Reproducibility of Analyzing 3D Transperineal Ultrasound Volumes Obtained in the First Phase of Labor - A Pilot Study.

The aim of this study was to investigate the reliability and reproducibility of transperineal ultrasound (TPUS) in the initial phase of labor. As TPUS is a common method, it could supplement vaginal palpation and even replace it in certain situations. In addition, we used a 4-dimensional method for the assessment of cervical effacement. 54 women in labor were included and underwent TPUS. The resulting images from the acquired 4D volumes were evaluated after the examination for the first time and a second time after 21 days. The measured values were cervical length, dilatation and effacement, the angle of progression (AoP), and head-perineum distance. 54 patients were examined. TPUS images were unable to be evaluated in 12 patients because of cervical dilatation of more than 5 cm or poor image quality. Thus, 42 measurements were included. The concordance correlation coefficients according to Lin are satisfactory overall, with one exception for cervical effacement. The accuracy component of cervical length (CCCLin: 0.93; accuracy: 1.00), dilatation (CCCLin: 0.93; accuracy: 1.00), and AoP (CCCLin: 0.87; accuracy: 1.00) is excellent and still high for the head-perineum distance (CCCLin: 0.89; accuracy: 0.96) and cervical effacement (CCCLin: 0.77; accuracy: 0.97). TPUS is a valuable noninvasive tool with good diagnostic accuracy for the AoP, cervical length, and dilatation. Our study provides support for the use of TPUS to complement a vaginal examination. It should not replace a digital examination but should serve as a suitable alternative method for monitoring labor progression in the future.

Assessment of Fetal Head–Perineum Distance via Ultrasound as a Predictor of Successful Vaginal Delivery Preceding Labor Induction

Assessment of Fetal Head–Perineum Distance via Ultrasound as a Predictor of Successful Vaginal Delivery Preceding Labor Induction

Predictive value of head-perineum distance measured at the initiation of the active second stage of labor on the mode of delivery: A prospective cohort study

ObjectiveThe objective was to assess the predictive value of head-perineum distance measured at the initiation of the active second stage of labor on the mode of delivery. Material and MethodsIt was a prospective cohort study in an academic Hospital of Rennes, France, from July 1, 2020 to April 4, 2021 including 286 full-term parturients who gave birth to a newborn in cephalic presentation. A double-blind ultrasound measurement of the head-perineum distance was performed during the second phase of labor within five minutes after the onset of pushing efforts. The primary outcome was the mode of delivery (spontaneous vaginal delivery versus instrumental vaginal delivery or cesarean section). We performed a multivariate analysis to determine the predictive value of the head-perineum distance by adjusting on potential confounders. ResultsOverall, 199 patients delivered by spontaneous vaginal delivery, 80 by instrumental vaginal delivery, and seven by cesarean section. The head-perineum distance measured at the beginning of pushing efforts was predictive of the mode of delivery with a threshold at 44 mm (crude: sensitivity = 56.8 % and specificity = 79.3 %; adjusted: sensitivity = 79.4 % and specificity = 87.4 %). The risk of medical intervention was higher when the head-perineum distance is>44 mm with an adjusted OR of 2.78 [1.38; 5.76]. ConclusionThe head-perineum distance measured at the initiation of the active second stage of labor is predictive of the mode of delivery. Head-perineum distance below 44 mm predicts a vaginal delivery with the best diagnostic performance, and optimizes the time to start pushing efforts.

Fetal Head–Perineum Distance on Transperineal Ultrasound as Predictor of Vaginal Delivery in Term Nulliparous Women Undergoing Induction of Labor

Fetal Head–Perineum Distance on Transperineal Ultrasound as Predictor of Vaginal Delivery in Term Nulliparous Women Undergoing Induction of Labor

Head Perineum Distance Measurement as a Predictor of Delivery Outcome Using Transperineal Sonography

Head Perineum Distance Measurement as a Predictor of Delivery Outcome Using Transperineal Sonography

Intrapartum Ultrasound in Maternal Lateral Position. A Prospective Observational Study

Background: Intrapartum ultrasound (ITU) techniques have been described only in maternal semi-recumbent position. However, other birthing positions, such as side-lying, are more comfortable for many mothers. The present study aimed to test the hypothesis that ITU measurements can be obtained in maternal lateral positions during the second stage of labor. Methods: A single-center, prospective observational study was conducted. Women who preferred a side-lying position during the second stage of labor participated in the study. The women were asked to grasp their upper knee and flex it to perform the ultrasound scan. The transducer was first placed in the frontal plane and then rotated to the midsagittal plane (the probe was placed at the level of the fourchette). Results: 34 women participated in the study. Position of the fetal head, angle of progression, and head-perineum distance with and without contraction were obtained in all women. There was a moderate correlation between the head-perineum distance with contraction and the ITU to birth time (r = 0.466; p = 0.009). Conclusions: ITU in maternal lateral position (side-lying) is a simple technique that avoids unnecessary changing of position during the second stage of labor.

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

BackgroundThe 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.MethodsA 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.ResultsOur 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.ConclusionVaginal 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.

Is sonographic measurement of head-perineum distance useful to predict obstetrical anal sphincter injury in case of vacuum delivery?

Determine if head-perineum distance (HPD) measurement before vacuum extraction (VE) was predictive of an obstetric anal sphincter injury (OASIS) occurrence. Retrospective, bicentric (Lille and Poissy, France) cohort study conducted from January 2019 to June 2020. All VE in singleton pregnancies of ≥34weeks were included. HPD measurement was performed without compression of the tissues before each VE. The judgment criterion was the occurrence of an OASIS. Of 12 568 deliveries, VE was performed in 1093 (8.6%). Among these 1093 women undergoing VE, 675 (61.7%) with HPD measurement were included. OASIS was found in 6.5% of women (n=44; 95% CI 4.5-8.7). HPD was not associated with OASIS (38.5±12.6mm in women with OASIS vs 37.4±12.0mm in women without; adjusted OR [aOR] per 5mm increase=0.92; 95% CI 0.79-1.06). Increased HPD was associated with higher risk of sequential extraction (aOR=1.19; 95% CI 1.06-1.32), extraction duration >10min (aOR=1.12; 95% CI 1.02-1.23) and shoulder dystocia (aOR=1.20; 95% CI 1.03-1.40). Ultrasound-measured head-perineum distance does not predict the occurrence of obstetric anal sphincter injury during a VE. The interest of HPD is more about predicting the success or difficulty of VE rather its specific complications.

Ultrasound assessment of fetal head position and station before operative delivery: Can it predict difficulty?

ObjectiveTo evaluate whether ultrasound assessment of fetal head position and station though head perineum distance (HPD), is more predictive of a difficult operative vaginal delivery (OVD) than digital examination. MethodsRetrospective, monocentric case control study including all singleton OVD at ≥34 weeks gestation. The principal criteria for a difficult OVD were based on a composite criterion of: an OVD considered “difficult” by the birth attendant, and/or two vacuum device detachments if a vacuum was used, and/or change of instrument, and/or a cesarean delivery for OVD failure. ResultsTwo hundred eighty-six OVDs were included, among which 65 (22.7%) were difficult. The area under the curve (AUC) for predicting difficult OVD according to fetal position from digital examination or ultrasound was 0.62 (95% CI: 0.54–0.70) and 0.66 (95% CI: 0.58–0.73), respectively. Regarding fetal station, the AUCs of HPD without and with pressure were 0.59 (95% CI: 0.51–0.66) and 0.60 (95% CI: 0.51–0.68), respectively. Factors associated with difficult OVD were posterior and transverse positions (OR: 2.931, 95% CI: 1.640–5.239; p= 0.0003), HPD without pressure (threshold of 37 mm, OR: 2.327, 95% CI: 1.247–4.245; p= 0.0080), and HPD with pressure (threshold of 17 mm, OR: 2.594, 95% CI: 1.230–5.429; p= 0.0114). ConclusionUltrasound assessment of fetal head position and station before OVD moderately predicts difficult OVD. Ultrasound assessment of posterior or transverse positions and HPD with a threshold of 37 mm (without compression of soft tissue) and 17 mm (with compression) were factors associated with difficult OVD.

Transperineal ultrasound assessment of fetal head elevation by maneuvers used for managing umbilical cord prolapse.

To assess objectively the degree of fetal head elevation achieved by different maneuvers commonly used for managing umbilical cord prolapse. This was a prospective observational study of pregnant women at term before elective Cesarean delivery. A baseline assessment of fetal head station was performed with the woman in the supine position, using transperineal ultrasound for measuring the parasagittal angle of progression (psAOP), head-symphysis distance (HSD) and head-perineum distance (HPD). The ultrasonographic measurements of fetal head station were repeated during different maneuvers, including elevation of the maternal buttocks using a wedge, knee-chest position, Trendelenburg position with a 15° tilt and filling the maternal urinary bladder with 100 mL, 300 mL and 500 mL of normal saline. The measurements obtained during the maneuvers were compared with the baseline measurements. Twenty pregnant women scheduled for elective Cesarean section at term were included in the study. When compared with baseline (median psAOP, 103.6°), the knee-chest position gave the strongest elevation effect, with the greatest reduction in psAOP (psAOP, 80.7°; P < 0.001), followed by filling the bladder with 500 mL (psAOP, 89.9°; P < 0.001) and 300 mL (psAOP, 94.4°; P < 0.001) of normal saline. Filling the maternal bladder with 100 mL of normal saline (psAOP, 96.1°; P = 0.001), the Trendelenburg position (psAOP, 96.8°; P = 0.014) and elevating the maternal buttocks (psAOP, 98.3°; P = 0.033) gave modest elevation effects. Similar findings were reported for HSD and HPD. The fetal head elevation effects of the knee-chest position, Trendelenburg position and elevation of the maternal buttocks were independent of the initial fetal head station, but that of bladder filling was greater when the initial head station was low. To elevate the fetal presenting part, the knee-chest position provides the best effect, followed by filling the maternal urinary bladder with 500 mL then 300 mL of fluid, respectively. Filling the bladder with 100 mL of fluid, the Trendelenburg position and elevation of the maternal buttocks have modest effects. © 2020 International Society of Ultrasound in Obstetrics and Gynecology.

The Usefulness of Intrapartum Transperineal Ultrasonography for the Prediction of Mode of Delivery

OBJECTIVE: We aimed to assess the accuracy of intrapartum transperineal ultrasonography that is non-invasive, easy to learn, rapid to perform, comfortable for pregnant women, and low-cost method to evaluate the progress of labor objectively.STUDY DESIGN: We evaluated two hundred-ten singleton pregnant women at term with cephalic presentation who went into active labor via intrapartum transperineal ultrasonography using the angle of progression and head-perineum distance. Maternal characteristics, conventional vaginal examination findings, mode of delivery, and neonatal results were noted. The data were compared using correlation and regression analysis.RESULTS: The relationships between the descent of clinical fetal head station, the increase of angle of progression (p=0.001), and the decrease of head-perineum distance (p=0.001) were statistically significant. The receiver operating characteristics curve showed that measurement of angle of progression with &lt;110.5 degrees (p=0.001) and measurement of head-perineum distance with &gt;52.5 millimeters (p=0.001) were associated with emergent cesarean delivery. For the prediction of delivery mode, both angle of progression and head-perineum distance had high sensitivity and specificity.CONCLUSIONS: Intrapartum transperineal ultrasonography parameters were in agreement with each other and conventional vaginal examination for determination of delivery mode. Head-perineum distance was a parity-dependent measurement whilst angle of progression was parity-independent.