Comparison of techniques used to deliver a deeply impacted fetal head at full dilation: a systematic review and meta-analysis

Anaesthetic considerations for impacted fetal head at caesarean delivery: a focused review

BACKGROUND

Impacted fetal head occurs when the fetal head is deeply engaged within the maternal pelvis and difficult to deliver during caesarean delivery. In order to deliver the fetal head, additional surgical manoeuvres and/or pharmacological tocolysis are needed. The aim of this focused review is to outline the incidence, risk factors, management and complications of this obstetric emergency from the perspective of the anaesthetist.

METHODS

Databases were searched for free text headings and subject headings associated with different permutations of terms related to impacted fetal head and caesarean delivery.

RESULTS

Impacted fetal head has been estimated to occur in 1.5 % of elective caesarean deliveries and 2.9-18.4% of all emergency caesarean deliveries at any cervical dilatation. Risk factors include advanced cervical dilatation, labour augmentation with oxytocin, prolonged second stage of labour, fetal malposition and junior grade of operating obstetrician. If impacted fetal head occurs, the anaesthetist in conjunction with the multidisciplinary team should consider decreasing the height of the operating table, providing a step for the obstetrician to stand on, placing the patient in the head down position, providing pharmacological tocolysis with glyceryl trinitrate (or nitroglycerin), beta-2 adrenoreceptor agonists or volatile anaesthetic agents, and managing complications such as postpartum haemorrhage.

CONCLUSION

Impacted fetal head is an obstetric emergency that the anaesthetist should be familiar with and has a vital role in managing. We propose an algorithm for management that may serve as a clinical decision aid.

Impacted fetal head at cesarean delivery

PURPOSE

Impacted fetal head (IFH) can be defined as the deep engagement of the fetal head in the maternal pelvis at the time of cesarean delivery that leads to its difficult or impossible extraction with standard surgical maneuvers. In this narrative review, we aimed to ascertain its incidence, risk factors, management and complications from the perspective of the anesthesiologist as a multidisciplinary team member.

METHODS

Databases were searched from inception to 24 January 2023 for keywords and subject headings associated with IFH and cesarean delivery.

RESULTS

IFH has an incidence of 2.9-71.8 % in emergency cesarean section. Maternal risk factors are advanced cervical dilatation, second stage of labor and oxytocin augmentation. Anesthetic and obstetric risk factors include epidural analgesia and trial of instrumental delivery and junior obstetrician, respectively. Neonatal risk factors are fetal malposition, caput and molding. Current evidence indicates a lack of confidence in the management of IFH across the multidisciplinary team. Simple interventions in IFH include lowering the height or placing the operating table in the Trendelenburg position, providing a step for the obstetrician and administering pharmacological tocolysis. Maternal complications are postpartum hemorrhage and bladder injury while neonatal complications include hypoxic brain injury, skull fracture and death. Surgical complications are reviewed to remind the anesthesiologist to anticipate and prepare for potential problems and manage complications in a timely manner.

CONCLUSION

The anesthesiologist has a fundamental role in the facilitation of delivery in IFH. We have proposed an evidence based management algorithm which may be referred to in this emergency situation.

Management of impacted fetal head at cesarean birth: A systematic review and meta-analysis

INTRODUCTION

Despite increasing incidence of impacted fetal head at cesarean birth and associated injury, it is unclear which techniques are most effective for prevention and management. A high quality evidence review in accordance with international reporting standards is currently lacking. To address this gap, we aimed to identify, assess, and synthesize studies comparing techniques to prevent or manage impacted fetal head at cesarean birth prior to or at full cervical dilatation.

MATERIAL AND METHODS

We searched MEDLINE, Emcare, Embase and Cochrane databases up to 1 January 2023 (PROSPERO: CRD420212750016). Included were randomized controlled trials (any size) and non-randomized comparative studies (n ≥ 30 in each arm) comparing techniques or adjunctive measures to prevent or manage impacted fetal head at cesarean birth. Following screening and data extraction, we assessed risk of bias for individual studies using RoB2 and ROBINS-I, and certainty of evidence using GRADE. We synthesized data using meta-analysis where appropriate, including sensitivity analyses excluding data published in potential predatory journals or at risk of retraction.

RESULTS

We identified 24 eligible studies (11 randomized and 13 non-randomized) including 3558 women, that compared vaginal disimpaction, reverse breech extraction, the Patwardhan method and/or the Fetal Pillow®. GRADE certainty of evidence was low or very low for all 96 outcomes across seven reported comparisons. Pooled analysis mostly showed no or equivocal differences in outcomes across comparisons of techniques. Although some maternal outcomes suggested differences between techniques (eg risk ratio of 3.41 [95% CI: 2.50-4.66] for uterine incision extension with vaginal disimpaction vs. reverse breech extraction), these were based on unreliable pooled estimates given very low GRADE certainty and, in some cases, additional risk of bias introduced by data published in potential predatory journals or at risk of retraction.

CONCLUSIONS

The current weaknesses in the evidence base mean that no firm recommendations can be made about the superiority of any one impacted fetal head technique over another, indicating that high quality training is needed across the range of techniques. Future studies to improve the evidence base are urgently required, using a standard definition of impacted fetal head, agreed maternal and neonatal outcome sets for impacted fetal head, and internationally recommended reporting standards.

Difficult fetal extraction in cesarean section: Number 8 - 2024

The main causes of difficult fetal extraction during cesarean section are deeply impacted fetal head and floating presentation of the fetus. Studies of management techniques for difficult fetal extraction during cesarean section and the maternal and neonatal results lack scientific evidence, as these predominantly come from case reports, small case series and expert opinions. The deeply impacted fetal head is usually associated with prolongation of the expulsion period and/or unsuccessful attempts at operative vaginal delivery. The main maternal complications associated with the management of the deeply impacted fetal head are lacerations in the lower uterine segment, hematomas in the uterine ligaments and injuries to the uterine vessels, cervix and/or urinary tract. The main neonatal complications associated with the management of a deeply impacted fetal head are intracranial hemorrhage, fractures of the skull and/or cervical spine, nerve injuries, perinatal asphyxia and even death. Among the maneuvers for delivery of the deeply impacted fetal head, the abdominovaginal delivery (push method) seems to be the most associated with maternal and neonatal complications. In the non-insinuated and floating fetal head, the internal podalic version followed by pelvic extraction differs from the reverse breech extraction (pull method). When the fetal head is high in the pelvis, the fetus is internally ejected before the extraction of its body segments, similar to the internal version performed in the vaginal delivery of the second twin with floating presentation of the fetus.

Impacted fetal head extraction methods at second stage cesarean and subsequent preterm delivery: A multicenter study

OBJECTIVE

Second-stage cesarean delivery (CD) is associated with subsequent preterm birth (PTB). It has been suggested that an increased risk of PTB after second-stage cesarean delivery could be linked to a higher chance of cervical injury due to the extension of the uterine incision. Previous studies have shown that reverse breech extraction is associated with lower rates of uterine incision extensions compared to the "push" method. We aimed to investigate the association between the method of fetal extraction during second-stage CD and the rate of spontaneous PTB (sPTB), as well as other maternal and neonatal outcomes during the subsequent pregnancy.

METHODS

This was a multicenter retrospective cohort study. The study population included women in their first subsequent singleton delivery following a second-stage CD between 2004 and 2021. The main exposure of interest was the method of fetal extraction in the index CD ("push" method vs. reverse breech extraction). The primary outcome of this study was sPTB <37 weeks in the subsequent pregnancy. Secondary outcomes were overall PTB, trial of labor, and other adverse maternal and neonatal outcomes. Univariate analysis was followed by multiple logistic regression modeling.

RESULTS

During the study period, 2969 index CD during second stage were performed, of those 583 met the inclusion criteria, of whom 234 (40.1%) had fetal extraction using the reverse breech extraction method, while 349 (59.9%) had the "push" method for extraction. In univariate analysis, women in those two groups had statistically similar rates of sPTB (3.7% vs. 3.0%; odds ratio [OR] 1.25, 95% CI: 0.49-3.19) and overall PTB (<37, <34 and <32 weeks), as well as other maternal, neonatal, and trial of labor outcomes. This was confirmed by multivariate analyses with an adjusted OR of 1.27 (95% CI: 0.43-3.71) for sPTB.

CONCLUSION

Among women with a previous second-stage CD, no significant difference was observed in PTB rates in the subsequent pregnancies following the "push" method compared to the reverse breech extraction method.

Operative delivery in the second stage of labor and preterm birth in a subsequent pregnancy: a systematic review and meta-analysis

OBJECTIVE

This study aimed to quantify the association between mode of operative delivery in the second stage of labor (cesarean delivery vs operative vaginal delivery) and spontaneous preterm birth in a subsequent pregnancy.

DATA SOURCES

MEDLINE, Embase, EmCare, CINAHL, the Cochrane Library, Web of Science: Core Collection, and Scopus were searched from database inception to April 1, 2023.

STUDY ELIGIBILITY CRITERIA

All retrospective cohort studies with participants who had a second-stage cesarean delivery (defined as intrapartum cesarean delivery at full cervical dilation) or operative vaginal delivery (including forceps- and/or vacuum-assisted delivery) and that reported the rate of preterm birth (either spontaneous or not specified) in subsequent pregnancy were included.

METHODS

Both a descriptive analysis and a meta-analysis were performed. A meta-analysis was performed for dichotomous data using the Mantel-Haenszel random-effects model and used the odds ratio as an effect measure with 95% confidence intervals. The risk of bias was assessed using Cochrane's 2022 Risk Of Bias In Non-randomized Studies of Exposure tool.

RESULTS

After screening 2671 articles from 7 databases, a total of 18 retrospective cohort studies encompassing 605,138 patients were included. The pooled rates of spontaneous preterm birth in a subsequent pregnancy were 6.9% (12 studies) after second-stage cesarean delivery and 2.6% (8 studies) after operative vaginal delivery. A total of 7 studies encompassing 75,460 patients compared the primary outcome of spontaneous preterm birth after second-stage cesarean delivery vs operative vaginal delivery in an index pregnancy with an odds ratio of 2.01 (95% confidence interval, 1.57-2.58) in favor of operative vaginal delivery. However, most studies did not include important confounding factors, did not address exposure misclassification because of failed operative vaginal delivery, and considered operative vaginal delivery as a homogeneous category with no distinction between forceps- and vacuum-assisted deliveries.

CONCLUSION

Although a synthesis of the existing literature suggests that the risk of spontaneous preterm birth is higher in those with a previous second-stage cesarean delivery than in those with operative vaginal delivery, the risk of bias in these studies is very high. Findings should be interpreted with caution.

Management of impacted fetal head at cesarean delivery

Globally, more than 1 in 5 women give birth by cesarean delivery, and at least 5% of these births are at full cervical dilatation. In these circumstances, and when labor has been prolonged in the first stage of labor, the fetal head can become low and wedged deep in the woman's pelvis, making it difficult to deliver the baby. This emergency is known as impacted fetal head. These are technically challenging births associated with serious risks to both the woman and the baby. The difficulty in disimpacting the fetal head increases maternal risks of hemorrhage and injury to adjacent organs and may have long-term consequences for future pregnancies. In addition, there can be associated neonatal consequences, such as skull fractures, brain hemorrhage, hypoxic brain injury, and, rarely, perinatal death. Globally, maternity staff are increasingly encountering this emergency, with studies in the United Kingdom suggesting that impacted fetal head may complicate as many as 1 in 10 emergency cesarean deliveries. Moreover, there has been a sharp increase in reports of perinatal brain injuries associated with impaction of the fetal head at cesarean delivery. When an impacted fetal head occurs, the maternity team can employ a range of approaches to help deliver the fetal head, including an assistant (another obstetrician or midwife) pushing the head up from the vagina, delivering the baby feet first (reverse breech extraction), administering tocolysis to relax the uterus, and using a balloon cephalic elevation device (Fetal Pillow) to elevate the baby's head. However, there is currently no consensus on how best to manage these births, resulting in a lack of confidence among maternity staff, variable practice, and potentially avoidable harm in some circumstances. This article examined the evidence for the prevention and management of this critical obstetrical emergency and outlined recommendations for best practices and training.

Experiences of Impacted Foetal Head: Findings from a Pragmatic Focus Group Study of Mothers and Midwives

INTRODUCTION

We aimed to explore the lived experiences of caesarean birth complicated by impaction of the foetal head, for mothers and midwives.

METHODS

A pragmatic, qualitative, focus group study of mixed-participants was conducted, face-to-face. They were postpartum women (n = 4), midwives (n = 4), and a postpartum midwife (n = 1) who had experience of either providing care for impacted foetal head, and/or had experienced it during their own labour, in Fife, United Kingdom. Data were transcribed and were analysed using template analysis.

RESULTS

Three main themes emerged through analysis: (i) current knowledge of impacted foetal head; (ii) current management of impacted foetal head; and (iii) experiences and outcomes of impacted foetal head. Each theme was made up of various initial codes when data were analysed inductively. Finally, each theme could be overlaid onto the three core principles of the Tydeman Tube: (1) to improve outcomes for mother and baby in the second stage of labour; (2) to reduce the risk of trauma to mother and baby in complicated births; and (3) to increase respectful care for women in labour; thus allowing for a neat analytic template.

CONCLUSION

A lack of consensus regarding definition, management, and training were highlighted by the midwives. Women anticipated caesarean birth in late labour as straightforward and were therefore unaware of this potential complication. Women and midwives would welcome any new device to facilitate delivery of the impacted foetal head (IFH) as long as it is fully evaluated prior to widespread introduction. Women were not averse to being part of this evaluation process.

Definition, management, and training in impacted fetal head at cesarean birth: a national survey of maternity professionals

INTRODUCTION

This study assessed views, understanding and current practices of maternity professionals in relation to impacted fetal head at cesarean birth, with the aim of informing a standardized definition, clinical management approaches and training.

MATERIAL AND METHODS

We conducted a survey consultation including the range of maternity professionals who attend emergency cesarean births in the UK. Thiscovery, an online research and development platform, was used to ask closed-ended and free-text questions. Simple descriptive analysis was undertaken for closed-ended responses, and content analysis for categorization and counting of free-text responses. Main outcome measures included the count and percentage of participants selecting predefined options on clinical definition, multi-professional team approach, communication, clinical management and training.

RESULTS

In total, 419 professionals took part, including 144 midwives, 216 obstetricians and 59 other clinicians (eg anesthetists). We found high levels of agreement on the components of an impacted fetal head definition (79% of obstetricians) and the need for use of a multi-professional approach to management (95% of all participants). Over 70% of obstetricians deemed nine techniques acceptable for management of impacted fetal head, but some obstetricians also considered potentially unsafe practices appropriate. Access to professional training in management of impacted fetal head was highly variable, with over 80% of midwives reporting no training in vaginal disimpaction.

CONCLUSIONS

These findings demonstrate agreement on the components of a standardized definition for impacted fetal head, and a need and appetite for multi-professional training. These findings can inform a program of work to improve care, including use of structured management algorithms and simulation-based multi-professional training.

Training for managing impacted fetal head at caesarean birth: multimethod evaluation of a pilot

BACKGROUND

Implementation of national multiprofessional training for managing the obstetric emergency of impacted fetal head (IFH) at caesarean birth has potential to improve quality and safety in maternity care, but is currently lacking in the UK.

OBJECTIVES

To evaluate a training package for managing IFH at caesarean birth with multiprofessional maternity teams.

METHODS

The training included an evidence-based lecture supported by an animated video showing management of IFH, followed by hands-on workshops and real-time simulations with use of a birth simulation trainer, augmented reality and management algorithms. Guided by the Kirkpatrick framework, we conducted a multimethod evaluation of the training with multiprofessional maternity teams. Participants rated post-training statements about relevance and helpfulness of the training and pre-training and post-training confidence in their knowledge and skills relating to IFH (7-point Likert scales, strongly disagree to strongly agree). An ethnographer recorded sociotechnical observations during the training. Participants provided feedback in post-training focus groups.

RESULTS

Participants (N=57) included 21 midwives, 25 obstetricians, 7 anaesthetists and 4 other professionals from five maternity units. Over 95% of participants agreed that the training was relevant and helpful for their clinical practice and improving outcomes following IFH. Confidence in technical and non-technical skills relating to managing IFH was variable before the training (5%-92% agreement with the pre-training statements), but improved in nearly all participants after the training (71%-100% agreement with the post-training statements). Participants and ethnographers reported that the training helped to: (i) better understand the complexity of IFH, (ii) recognise the need for multiprofessional training and management and (iii) optimise communication with those in labour and their birth partners.

CONCLUSIONS

The evaluated training package can improve self-reported knowledge, skills and confidence of multiprofessional teams involved in management of IFH at caesarean birth. A larger-scale evaluation is required to validate these findings and establish how best to scale and implement the training.

Longitudinal change in cervical length following vaginal or abdominal cervical cerclage: a randomized comparison

BACKGROUND

Cervical cerclage has been shown to reduce the risk of recurrent spontaneous preterm birth in a high-risk patient population; however, the mechanism is not well understood. Transabdominal cerclage is superior to low and high vaginal cerclage in reducing early spontaneous preterm birth and fetal loss in women with previous failed vaginal cerclage. Cervical length measurements are commonly used to monitor high-risk women and may explain the mechanism of success.

OBJECTIVE

This study aimed to evaluate the rate of change in longitudinal cervical length after randomized placement of low transvaginal, high transvaginal, or transabdominal cerclage in women with a previous failed vaginal cerclage.

STUDY DESIGN

This was a planned analysis of longitudinal transvaginal ultrasound cervical length measurements from patients enrolled in the Vaginal Randomised Intervention of Cerclage trial, a randomized controlled trial comparing transabdominal cerclage or high transvaginal cerclage with low transvaginal cerclage. Cervical length measurements at specific gestational ages were compared over time and between groups, using generalized estimating equations fitted using the maximum-likelihood random-effects estimator. In addition, cervical length measurements were compared in women with transabdominal cerclage placed before and during pregnancy. The diagnostic accuracy of cervical length as a predictor of spontaneous preterm birth at <32 weeks of gestation was explored.

RESULTS

This study included 78 women who underwent longitudinal cervical length assessment (70% of the analyzed cohort) with a history of failed cerclage, of whom 25 (32%) were randomized to low transvaginal cerclage, 26 (33%) to high transvaginal cerclage, and 27 (35%) to transabdominal cerclage. Abdominal cerclage was superior to low (P=.008) and high (P=.001) vaginal cerclage at maintaining cervical length over the surveillance period (14 to 26 weeks of gestation) (+0.08 mm/week, 95% confidence interval, -0.40 to 0.22; P=.580). On average, the cervical length was 1.8 mm longer by the end of the 12-week surveillance period in women with transabdominal cerclage (+1.8 mm; 95% confidence interval, -7.89 to 4.30; P=.564). High vaginal cerclage was no better than low cervical cerclage in the prevention of cervical shortening; the cervix shortened by 13.2 mm over 12 weeks in those with low vaginal cerclage (95% confidence interval, -21.7 to -4.7; P=.002) and by 20 mm over 12 weeks in those with high vaginal cerclage (95% confidence interval, -33.1 to -7.4; P=.002). Preconception transabdominal cerclage resulted in a longer cervix than those performed during pregnancy; this difference was significant after 22 weeks of gestation (48.5 mm vs 39.6 mm; P=.039). Overall, cervical length was an excellent predictor of spontaneous preterm birth at <32 weeks of gestation (receiver operating characteristic curve, 0.92; 95% confidence interval, 0.82-1.00).

CONCLUSION

In women with a previous failed cervical cerclage, in the next pregnancy, the cervical length in women treated with vaginal cerclage funneled and shortened over time, whereas there was preservation of cervical length in women who receive transabdominal cerclage. Cervical length remained longer in transabdominal procedures performed before pregnancy than in transabdominal procedures performed during pregnancy. Overall, cervical length was an excellent predictor of spontaneous preterm birth in our cohort. Our findings may explain the mechanism of benefit for transabdominal cerclage, with its high placement better maintaining the structural integrity of the cervix at the level of the internal os.

The acceptability and feasibility of a randomised trial exploring approaches to managing impacted fetal head during emergency caesarean section: a qualitative study

BACKGROUND

Caesarean sections (CS) account for 26% of all births in the UK, of which at least 5% are done at full dilatation, in the second stage of labour. Second stage CS may be complicated by the fetal head being deeply impacted in the maternal pelvis, requiring specialist skills to achieve a safe birth. Numerous techniques are used to manage impacted fetal head, however, there are no national clinical guidelines in the UK.

AIM

To explore health professionals' and women's views on the acceptability and feasibility of a randomised controlled trial (RCT) designed to explore approaches to managing an impacted fetal head during emergency CS.

METHODS

Semi-structured interviews with 10 obstetricians and 16 women (6 pregnant and 10 who experienced an emergency second stage CS). Interviews were transcribed and analysed using systematic thematic analysis.

RESULTS

The findings considered the time at which you obtain consent, how and when information about the RCT is presented, and barriers and facilitators to recruiting health professionals and women into the RCT. Obstetricians emphasised the importance of training in the techniques, as well as the potential conflict between the RCT protocol and current site or individual practices. Women said they would trust health professionals' to use the most appropriate technique and abandon the RCT protocol if necessary. Similarly, obstetricians raised the tension between the RCT protocol versus safety in reverting to what they knew under emergency situations. Both groups reflected on how this might affect the authenticity of the results. A range of important maternal, infant and clinical outcomes were raised by women and obstetricians. However, there were varying views on which of the two RCT designs presented to participants would be preferred. Most participants thought the RCT would be feasible and acceptable.

CONCLUSIONS

This study suggests an RCT designed to evaluate different techniques for managing an impacted fetal head would be feasible and acceptable. However, it also identified a number of challenges that need to be considered when designing such an RCT. Results can be used to inform the design of RCTs in this area.

Techniques for managing an impacted fetal head at caesarean section: A systematic review

A complication arising at caesarean birth when the baby's head is deeply engaged in the pelvis and may be difficult to deliver, is known as an 'impacted fetal head'. This obstetric emergency occurs in 16% of second stage caesarean sections. Multiple techniques are described in the literature to manage the complication but there is no consensus regarding which technique results in the best maternal and neonatal outcomes. The objective of this review is to determine which technique for managing impacted fetal head at caesarean section has the best maternal and neonatal outcomes. A literature search of three electronic databases was conducted in November 2021. Studies directly comparing two methods for the management of impacted fetal head at caesarean section in the second stage were included. Systematic reviews, meta-analyses, case-control studies, and studies not fitting the search criteria were excluded. Data was extracted in Covidence and meta-analysis of the six most commonly reported outcomes was conducted using RevMan 5.4. In total, 16 studies (3344women) were included. 13 studies (2506women) compared the push method with reverse breech extraction. meta-analysis showed that risk of extension of the uterine incision, blood transfusion, bladder injury, postpartum haemorrhage, NICU admission and Apgar score <7 at 5 min were significantly higher with the push method compared with reverse breech extraction. Three studies (838women) compared the push method with Patwardhan's technique. meta-analysis of studies comparing the push method with Patwardhan's technique found no significant differences between the two groups in any of the six maternal or neonatal outcomes. Evidence derived from small, inadequately powered studies suggests reverse breech extraction is associated with better outcomes than the push method. The method which produces the best outcomes is still unknown as not all methods have been tested. Further high quality, adequately powered RCTs are warranted for definitive conclusions to be drawn and to ameliorate the paucity of evidence on how best to manage this complication.

Validation of a novel birth simulator for impacted fetal head at cesarean section: An observational simulation study

INTRODUCTION

Impacted fetal head (IFH) is a challenging complication of cesarean section (CS) associated with significant morbidity. Training opportunities for IFH have been reported as inconsistent and inadequate. This study assessed the validity of a novel birth simulator for IFH at cesarean section.

MATERIAL AND METHODS

Obstetricians and midwives collaborated with model-making company, Limbs & Things (UK), to modify the original PROMPT Flex® simulator and develop a new "Enhanced CS Module" for IFH at cesarean section. Changes included addition of a retractable uterus and restricted pelvic inlet, and the fetal mannequin was modified to allow accurate limb articulation and flexion at the waist. Obstetricians and midwives from three maternity units in Southwest England were individually recorded, each undertaking three simulated scenarios of IFH at cesarean section. Obstetricians were asked to deliver the fetal head and midwives, to perform a vaginal push-up. Participants completed a questionnaire on realism (face validity) and usefulness for training (content validity) with five-point Likert scale responses. Construct validity was assessed by testing an a priori hypothesis that "experts" (consultant obstetricians with >7 years' experience) would be more likely to achieve delivery than "novices" (registrars with <7 years' experience). Performance variables were compared between groups using Chi-square and Mann-Whitney U-tests.

RESULTS

In all, 105 simulated scenarios were undertaken by 35 obstetricians and midwives. A range of techniques were employed to deliver the IFH including change of hand, vaginal disimpaction and reverse breech extraction. Overall, 86% (30/35) described the model as fairly (4)/very realistic (5) (median = 4, interquartile range [IQR] = 4-5). The model was considered fairly (4)/very useful (5) for training by 97% (34/35; median = 5; IQR = 5-5). Experts delivered the fetal head in all simulations (36/36) and novices delivered the head in 76.9% (30/39) (p = 0.002). Experts delivered the fetal head 58% quicker than novices (median = 66.8 s, IQR = 53-86 vs median = 104 s, IQR = 67.7-137).

CONCLUSIONS

This novel birth trainer realistically simulates IFH at cesarean section and allows rehearsal of all disimpaction techniques. It was reported to be very useful for training and distinguishes between novice and expert obstetricians. Techniques for IFH are difficult to learn experientially. Simulation is likely to provide an effective and safe form of training.

Fetal station at caesarean section and risk of subsequent preterm birth - A cohort study

OBJECTIVES

An increased risk of preterm birth (PTB) following a caesarean section (CS) in the second stage of labor has been demonstrated. We aimed to investigate the relationship between the station of the presenting fetal part and the surgical technique at first CS, and the risk of subsequent PTB.

STUDY DESIGN

This was a cohort study of 11,850 women in Sweden, delivered by CS in 2001-2007 at any of 23 birth units, with a second delivery in 2001-2009. Clinical information was retrieved from electronic birth records linked to national health registers. The risk of subsequent PTB was analyzed by fetal station, defined as low (at or below the ischial spines) or high (above the ischial spines), and aspects of the surgical technique at index CS. Associations were explored with logistic regression and results are presented as odds ratios (ORs) with 95% confidence intervals (CIs), by type and severity (very early < 32 gestational weeks and moderate preterm 32-36 gestational weeks) of PTB. Multiple logistic regression included adjustments for maternal age, gestational age at first delivery, and inter-delivery interval.

RESULTS

Out of 11,850 women delivered by CS, 1,016 (8.6%) delivered preterm in their subsequent pregnancy. There was an increased likelihood of spontaneous PTB, but not with medically indicated PTB, after an index CS with the fetal presenting part at a low station (aOR 1.61, 95% CI 1.23-2.11). CS performed at a low station was associated with birth < 32 gestational weeks (aOR 1.73, 95% CI 1.05-2.84) and birth at 32-36 gestational weeks (aOR 1.29, 95% CI 1.00-1.65), compared with high fetal station. Thickness of the uterine wall, incision type, and closure of the uterus at index CS did not affect the risk.

CONCLUSION

A primary CS at a low station was associated with a subsequent spontaneous PTB, but not medically indicated PTB. Surgical technique at index CS did not alter the risk.

Maternal and neonatal outcomes associated with delivery techniques for impacted fetal head at cesarean section: a systematic review and meta-analysis

OBJECTIVES

Late first-stage or second-stage cesarean section is commonly associated with fetal head impaction, leading to maternal and neonatal complications. This situation requires safe delivery techniques, but the optimal management remains controversial. The aim of this meta-analysis was to compare maternal and neonatal outcomes associated with delivery techniques via cesarean section.

METHODS

An electronic search of three databases, from inception to June 2021, was conducted. Cohort and randomised comparative studies on maternal and neonatal outcomes associated with techniques to deliver an impacted fetal head during cesarean section were included. The methodological quality of the primary studies was assessed. Review Manager 5.4 was used for statistical analyses.

RESULTS

Nineteen articles, including 2,345 women were analyzed. Three fetal extraction techniques were identified. Meta-analyses showed that the "pull" technique carries lower risks as compared to the "push" technique and the "Patwardhan" technique is safer compared to the "push" or the "push and pull" technique.

CONCLUSIONS

In the absence of robust evidence to support the use of a specific technique, the choice of the obstetrician should be based on best available evidence. Our study suggests that the "pull", as well as the "Patwardhan" technique represent safe options to deliver an impacted fetal head.

Impacted fetal head during second stage Caesarean birth: A prospective observational study

OBJECTIVE

To determine the incidence of, and complication rates from, impacted fetal head at full dilatation Caesarean birth in the UK, and record what techniques were used.

DESIGN

Prospective observational study using the UK Obstetric Surveillance System (UKOSS).

SETTING

159 (82%) of the 194 UK hospitals with obstetric units.

POPULATION

All women who underwent second stage Caesarean birth in the UK between 1st March and 31st August 2019. Further information was collected on cases where a dis-impaction technique was used, or the operating surgeon experienced 'difficulty' in delivering the head.

METHODS

Prospective observational study.

MAIN OUTCOME MEASURES

Technique(s) used, maternal and neonatal outcomes.

RESULTS

3,518 s stage Caesarean births reported. The surgeon used a dis-impaction technique or reported 'difficulty' in 564 (16%) of these. The most common dis-impaction techniques used were manual elevation of the head by an assistant through the vagina (n = 235) and a fetal "pillow" (n = 176). Thirteen babies (2%) died or sustained severe injury. Four babies died (two directly attributable to the impacted fetal head).

CONCLUSIONS

Difficulty with delivery of the fetal head and the use of dis-impaction techniques during second stage Caesarean sections are common but there is no consensus as to the best method to achieve delivery and in what order.

A comparison of technicques to disimpact the fetal head on a second stage caesearean simulator

Background

The rate of second stage caesarean section (CS) is rising with associated increases in maternal and neonatal morbidity, which may be related to impaction of the fetal head in the maternal pelvis. In the last 10 years, two devices have been developed to aid disimpaction and reduce these risks: the Fetal Pillow (FP) and the Tydeman Tube (TT). The aim of this study was to determine the distance of upward fetal head elevation achieved on a simulator for second stage CS using these two devices, compared to the established technique of per vaginum digital disimpaction by an assistant.

Methods

We measured elevation of the fetal head achieved with the two devices (TT and FP), compared to digital elevation, on a second stage Caesearean simulator (Desperate Debra ™ set at three levels of severity. Elevation was measured by both a single operator experienced with use of the TT and FP and also multiple assistants with no previous experience of using either device. All measurements were blinded

Results

The trained user achieved greater elevation of the fetal head at both moderate and high levels of severity with the TT (moderate: 30mm vs 12.5mm p<0.001; most severe: 25mm vs 10mm p<0.001) compared to digital elevation. The FP provided comparable elevation to digital at both settings (moderate: 10 vs 12.5mm p=0.149; severe 10 vs 10mm p=0.44).

With untrained users, elevation was also significantly greater with the TT compared to digital elevation (20mm vs 10mm p<0.01). However digital disimpaction was significantly greater than the FP (10mm vs 0mm p<0.0001).

Conclusion

On a simulator, with trained operators, the TT provided greater fetal head elevation than digital elevation and the FP. The FP achieved similar elevation to the digital technique, especially when the user was trained in the procedure.

Duration of the second stage of labour and risk of subsequent spontaneous preterm birth

OBJECTIVES

To determine the risk of spontaneous preterm birth (sPTB) associated with the length of second stage of labour in the first term delivery.

DESIGN

Retrospective cohort study.

SETTING

University hospital.

POPULATION

Women with first two consecutive singleton births and the first birth at term. Those who did not reach the second stage of labour in the first delivery were excluded.

METHODS

Charts from 2007 to 2019 were reviewed.

MAIN OUTCOME MEASURES

Rate of sPTB (<37 weeks of gestation) in the second delivery.

RESULTS

Of 13 958 women who met study inclusion criteria, 1464 (10.5%) parturients had a prolonged second stage (≥180 min) in their first term delivery. The rate of sPTB in the second delivery was similar in those with and without a prolonged second stage in first delivery (2.8% versus 2.8%; adjusted odds ratio [aOR] 1.35, 95% CI 0.96-1.90). After adjustment for mode of delivery, prolonged second stage was also not associated with subsequent sPTB in those who delivered by spontaneous and operative vaginal delivery. Those delivered by second-stage caesarean section in the first delivery had a higher risk of sPTB in the second delivery (25/526, 4.8%; aOR 2.66, 95% CI 1.71-4.12; p < 0.001), with a more pronounced risk in those with second-stage caesarean following a prolonged second stage of labour (15/259, 5.8%; aOR 3.40, 95% CI 1.94-5.94; p < 0.001).

CONCLUSION

Second-stage duration in a first term vaginal delivery is not associated with subsequent sPTB. The risk of sPTB is increased following second-stage caesarean section, particularly if performed after a prolonged second stage.

Is duration of passive second stage associated with a risk of hysterotomy extension during cesarean?

Objective

To assess obstetric factors associated with hysterotomy extension among women undergoing a second-stage cesarean.

Study design

This 5-year retrospective cohort study (2013–2017) included all women with second-stage cesarean deliveries of live-born singleton fetuses in cephalic presentation at term. It took place at a tertiary center that practices delayed pushing. We performed univariable and multivariable logistic regression to assess the maternal, obstetric, and neonatal factors associated with hysterotomy extension mentioned in the surgical report. Operative time, postpartum hemorrhage, and maternal complications were also studied.

Results

Of the 3350 intrapartum cesareans, 2637 were performed at term for singleton fetuses in cephalic presentation: 747 (28.3%) during the second stage of labor, 83 (11.1%) of which were complicated by a hysterotomy extension. The median duration of the passive phase of the second stage did not differ between women with and without an extension (164 min versus 160 min, P = 0.85). No other second-stage obstetric characteristics, i.e., duration of the active phase, fetal head station, or fetal malposition, were associated with the risk of extension. Factors significantly associated with extension were the surgeon’s experience and forceps use during the cesarean. Women with an extension, compared to women without one, had a longer median operative time (49 min versus 32 min, P<0.001) and higher rates of postpartum hemorrhage and blood transfusion (respectively, 30.1% versus 15.1%, p = 0.002 and 7.2% versus 2.4%, P = 0.03).

Conclusion

The risk of a hysterotomy extension does not appear to be associated with second-stage obstetric characteristics, including the duration of the passive phase of this stage. In our center, which practices delayed pushing, prolonging this passive phase beyond 2 hours does not increase the risk of hysterotomy extension in second-stage cesareans.

Committee Opinion No. 415: Impacted Fetal Head, Second-Stage Cesarean Delivery

OBJECTIVE

To review the most effective clinical approaches to disengage an impacted fetal head during cesarean delivery.

TARGET POPULATION

Women who undergo cesarean delivery of an infant with a deeply impacted head.

OPTIONS

The "push" technique (from below) or the "pull" technique (reverse breech extraction).

OUTCOMES

Proper management of this clinical scenario can reduce maternal and perinatal morbidity and mortality.

BENEFITS, HARMS, AND COSTS

Using an evidence-informed approach when an impacted fetal head is anticipated has the potential to reduce maternal and fetal complications and short- and long-term harm and their associated costs. Research into the value of simulation learning, regular labour assessments, and team preparedness for possible interventions will help inform quality care.

EVIDENCE

The following search terms were entered into PubMed/Medline, Google Scholar, and Cochrane for the publication period 2012-2019: • 'Guidelines' 'manual' • 'Caesarean Section' • 'full dilation' • 'operative delivery' • 'impacted head' • 'Caesarean' AND 'full dilation' AND 'impacted head' • 'Caesarean' AND 'second stage of labour' OR 'second stage' AND 'impacted head' • 'Caesarean' OR 'operative delivery' AND 'impacted head' A total of 32 articles were retrieved and 24 were deemed appropriate to include as references. Many of these articles represented expert opinion. Randomized controlled trials had small sample sizes and were conducted in settings that limit the generalizability of their findings to the Canadian population.²⁰ INTENDED USERS: Intrapartum health care providers.

Complete cervical inversion and nearly inappropriate stitching with cesarean section during the second stage of labor: a case report

Cesarean section is a common obstetric operation and an important method for saving the lives of mothers and their neonates in dangerous situations. Nevertheless, cesarean section has a higher risk and might have more complications compared with natural delivery. A reasonable choice of delivery method is important for maternal and neonatal health. The incidence of complications after cesarean section for mothers and neonates during the second stage of labor significantly increases compared with planned cesarean section. During the second stage of labor, the fetal head is deep in the pelvic cavity. If a cesarean section is performed at this stage, it is prone to causing complications, including difficult delivery of the fetal head, delayed uterine incision, and massive hemorrhage, which seriously threaten the health of the mother and her neonate. For the first time, we report a case of cesarean section after complete opening of the uterine orifice, which led to almost mistakenly suturing the cervix to the uterus. This report will hopefully help surgeons anticipate such incidents during cesarean section in the future.

Outcomes of second stage cesarean section following the use of a fetal head elevation device: A systematic review and meta-analysis

OBJECTIVES

To explore maternal and perinatal outcomes of women undergoing full dilatation cesarean section (CS) who had compared to those who did not have application of fetal head elevation device (FHED).

MATERIAL AND METHODS

Pubmed, Embase, Cinahl, Clinical Trial.Gov and Google Scholar databases were searched. Inclusion criteria were studies exploring maternal and perinatal outcomes in women having compared to those not having FHED at full dilatation CS. The outcomes explored were: hysterotomy to delivery time (sec), mean estimated blood loss (ml), blood loss > 1000 mL, need for blood transfusion, uterine incision extension, operative complications, need for re-operation, urinary retention, hospital re-admission, length of in hospital stay, Apgar score < 3 at 1 min, Apgar score < 7 at 5 min, neonatal arterial Ph, arterial pH < 7.1, admission to neonatal intensive care unit (NICU), neonatal sepsis, need for neonatal endotracheal intubation, neonatal death. Random effect head-to-head meta-analyses combining summary mean difference (MD), and odd ratio (OR) were used to analyze the data.

RESULTS

Ten studies (1326 women) were included. The mean time from hysterotomy to delivery was lower in women having compared to those not having FHED (MD: -52.26 s, 95 % CI -55.2 to -34.94, p < 0.001). Women who had FHED had also a lower mean estimated blood loss (MD: -130.82 mL, 95 % CI -130.1 to -381.0; p < 0.001) and a shorter stay in the hospital (MD: -0.884 h, 95 % CI -1.07 to -0.70; p < 0.001) compared to controls. Pregnant women having FHED at full dilatation CS had a lower risk of uterine incision extension (OR: 0.50, 95 % CI 0.3 to 0.9; p = 0.02), need for blood transfusion (OR: 0.39, 95 % CI 0.2 to 0.7; p = 0.04) and operative complications (OR: 0.44, 95 % CI 0.2 to 0.9; p = 0.03) compared to controls, while there was no difference in the other maternal outcomes between the two groups. When exploring perinatal outcome, women who received FHED had higher mean arterial pH values (MD: 0.617, 95 % CI 0.43 to 0.88; p < 0.001) and a lower risk of neonatal sepsis (OR: 0.10, 95 % CI 0.01 to 0.99; p = 0.05) and admission to NICU (OR: 0.63, 95 % CI 0.5 to 0.9; p = 0.008) compared to controls.

CONCLUSION

Application of FHED at full dilatation CS seems to be associated with improvement in some maternal and neonatal outcomes.

Impacted fetal head: A retrospective cohort study of emergency caesarean section

OBJECTIVE

To investigate risk factors, management and outcomes of impacted fetal head (IFH) at caesarean section (CS).

STUDY DESIGN

This is a retrospective cohort study of all women with singleton, cephalic pregnancies who had an emergency CS during one-year (2016) at North Bristol NHS Trust, UK (n = 838). The incidence of caesarean section at full dilatation (CSFD) and IFH were calculated using the annual birth rate. To identify risk factors for IFH, maternal, perinatal and intrapartum characteristics were compared according to the presence or absence of IFH, and separately for first- and second-stage CS. Techniques employed to disimpact the fetal head were described. Univariable and multivariable comparisons of maternal and perinatal outcomes were made between cases with and without an IFH. Characteristics and outcomes were compared using modified Poisson regression.

RESULTS

CSFD accounted for 2.1 % of all births. IFH complicated 1.5 % of all births (11.3 % of emergency CS), with 55.8 % occurring prior to full cervical dilatation. Increased rates of IFH at CS were associated with: oxytocin augmentation (RR = 2.47 [1.61-3.80]), full cervical dilatation (RR = 4.24 [2.96-6.07], mid/low station (RR = 4.14 [2.72-6.32]), moulding (RR = 4.39 [2.55-7.54]) and caput (RR = 6.60 [3.09-14.10]). Junior operators documented IFH more than consultants (RR = 9.61 [1.35-68.2]). The strategies recorded for managing IFH included: tocolysis, reverse breech extraction and vaginal push up (33.7 %, 14.7 % and 11.6 % cases respectively) with two or more techniques used in 21.1 % cases. IFH at CS was independently associated with an increased risk of uterine extensions (RR = 3.09 [1.96-4.87]) and a composite adverse perinatal outcome (RR = 1.66 [1.21-2.28]).

CONCLUSIONS

IFH is a common and heterogeneous complication associated with increased complications for both mother and baby, independent of those of CSFD. Obstetricians must remain vigilant to the possibility of IFH at all emergency CS, particularly those at full cervical dilatation or with evidence of obstructed labour. There is an urgent need for a standardised management algorithm and training in evidence-based disimpaction techniques.

Opinion de comité n° 415 : Césarienne au deuxième stade avec enclavement de la tête fœtale

OBJECTIF

Passer en revue les stratégies cliniques les plus efficaces pour désengager une tête fœtale enclavée pendant la césarienne.

POPULATION CIBLE

Les femmes qui subissent une césarienne lorsque la tête fœtale est fortement enclavée.

OPTIONS

La technique par poussée (par le bas) ou par traction (grande extraction du siège par voie abdominale). RéSULTATS: La prise en charge adéquate de cette situation clinique peut réduire les risques de morbidité et mortalité maternelle et périnatale. BéNéFICES, RISQUES ET COûTS: Lorsque l'on anticipe un enclavement de la tête fœtale, il est possible de réduire le risque de complications maternelles et fœtales, les atteintes à court et à long terme ainsi que les coûts associés en adoptant une stratégie fondée sur des données probantes. Les recherches sur la valeur de l'apprentissage par simulation, les évaluations régulières pendant le travail et la préparation de l'équipe aux interventions possibles aideront à orienter les soins de qualité. DONNéES PROBANTES: Les termes de recherche suivants ont été utilisés dans les bases de données PubMed-Medline, Google Scholar et Cochrane pour la période de publication de 2012 à 2019 : • "Guidelines" "manual" • "Caesarean Section" • "full dilation" • "operative delivery" • "impacted head" • "Caesarean" AND "full dilation" AND "impacted head" • "Caesarean" AND "second stage of labour" OR "second stage" AND "impacted head" • "Caesarean" OR "operative delivery" AND "impacted head" Au total, 32 articles ont été récupérés et 24 ont été jugés adéquats comme références. Plusieurs de ces articles étaient des opinions d'experts. Les essais cliniques randomisés avaient des échantillons de petite taille et ont été menés dans des contextes qui limitent la généralisabilité de leurs résultats à la population canadienne²⁰.

PROFESSIONNELS CIBLES

Fournisseurs de soins de santé intrapartum.

Perinatal outcome after vacuum assisted delivery with digital feedback on traction force; a randomised controlled study

Background

Low and mid station vacuum assisted deliveries (VAD) are delicate manual procedures that entail a high degree of subjectivity from the operator and are associated with adverse neonatal outcome. Little has been done to improve the procedure, including the technical development, traction force and the possibility of objective documentation. We aimed to explore if a digital handle with instant haptic feedback on traction force would reduce the neonatal risk during low or mid station VAD.

Methods

A two centre, randomised superiority trial at Karolinska University Hospital, Sweden, 2016–2018. Cases were randomised bedside to either a conventional or a digital handle attached to a Bird metal cup (50 mm, 80 kPa). The digital handle measured applied force including an instant notification by vibration when high levels of traction force were predicted according to a predefined algorithm. Primary outcome was a composite of hypoxic ischaemic encephalopathy, intracranial haemorrhage, seizures, death and/or subgaleal hematoma. Three hundred eighty low and mid VAD in each group were estimated to decrease primary outcome from six to 2 %.

Results

After 2 years, an interim analyse was undertaken. Meeting the inclusion criteria, 567 vacuum extractions were randomized to the use of a digital handle (n = 296) or a conventional handle (n = 271). Primary outcome did not differ between the two groups: (2.7% digital handle vs 2.6% conventional handle). The incidence of primary outcome differed significantly between the two delivery wards (4% vs 0.9%, p < 0.05). A recalculation of power revealed that 800 cases would be needed in each group to show a decrease in primary outcome from three to 1 %. This was not feasible, and the study therefore closed.

Conclusions

The incidence of primary outcome was lower than estimated and the study was underpowered. However, the difference between the two delivery wards might reflect varying degree of experience of the technical equipment. An objective documentation of the extraction procedure is an attractive alternative in respect to safety and clinical training. To demonstrate improved safety, a multicentre study is required to reach an adequate cohort. This was beyond the scope of the study.

Trial registration

ClinicalTrials.gov NCT03071783, March 1, 2017, retrospectively registered.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12884-021-03604-z.

The acceptability to women of techniques for managing an impacted fetal head at caesarean section and of randomised trials evaluating those techniques: a qualitative study

BACKGROUND

This study aimed to explore women's views on the acceptability of different techniques for managing an impacted fetal head at caesarean; and the feasibility and acceptability of conducting a trial in this area.

METHODS

Qualitative semi-structured interviews with a systematic sample of women who experienced second stage emergency caesarean section at a tertiary National Health Service (NHS) hospital in England, UK. Thematic analysis was used to extract women's views.

RESULTS

Women varied in their perceptions of the acceptability of different techniques for managing impacted fetal head. Trust in medical expertise and prioritising the safety of the baby were important contextual factors. Greater consensus was found around informed choice in trials where subthemes considered the timing of invitation, reduced capacity to give consent in emergency situations, and the importance of birth outcomes and having good rapport with healthcare professionals who invite women into trials. Finally, women reflected on the importance of supportive antenatal and postpartum education for impacted fetal head.

CONCLUSIONS

This research provides information on the acceptability of techniques and any trial to evaluate these techniques. Findings illustrate the importance of context and quality of care to both acceptability and approaching women to take part in a future trial.

Effectiveness of the fetal pillow to prevent adverse maternal and fetal outcomes at full dilatation cesarean section in routine practice

INTRODUCTION

The fetal pillow has been suggested to reduce maternal trauma and fetal adverse outcomes when used to disimpact the fetal head at full dilatation cesarean section.

MATERIAL AND METHODS

We performed a retrospective cohort study of the use of the fetal pillow device at full dilatation cesarean section between September 2014 and March 2018 at Liverpool Women's Hospital, a large UK teaching hospital.

RESULTS

There were 471 cases of full dilatation cesarean section during the study period and 391 were included for the analysis; 170 used the fetal pillow and 221 were delivered without. We did not demonstrate any benefit in the significant maternal outcomes of estimated blood loss >1000 mL or >1500 mL, need for blood transfusion, or duration of hospital stay, from the use of the fetal pillow. We did not demonstrate any improvement in fetal outcome following use of the fetal pillow for arterial pH <7.1, Apgar score <7 at 5 minutes or admission to the neonatal unit. For deliveries undertaken at or below the level of the ischial spines there was likewise no benefit from fetal pillow use, except in a reduced risk of an arterial pH <7.1 (relative risk 0.39, 95% CI 0.20-0.80, P = .01); however, admission to the neonatal unit was unaffected.

CONCLUSIONS

This is the largest study to date on the use of the fetal pillow at full dilatation cesarean section. We did not demonstrate any statistically significant benefit from the use of the fetal pillow to prevent any maternal or fetal adverse outcomes at full dilatation cesarean section in routine clinical use. Further randomized studies are required to prove clinical benefit from this device before more widespread use.

Impacted foetal head at caesarean section: a national survey of practice and training

This is a national survey of UK obstetric trainees and consultant labour ward leads designed to investigate the current practice and training for an impacted foetal head (IFH) at Caesarean Section (CS). An anonymous, on-line survey was disseminated to trainees via Postgraduate Schools and RCOG trainee representatives, and to labour ward leads via their national network. Three hundred and forty-five obstetric trainees and consultants responded. The results show that IFH is variably defined and encountered by most UK obstetricians (98% had encountered IFH and 76% had experienced it before full cervical dilatation). There is significant variation in management strategies, although most respondents would use a vaginal push up to assist delivery prior to reverse breech extraction. Responses revealed a paucity of training and lack of confidence in disimpaction techniques: over one in ten respondents had not received any training for IFH and less than half had received instruction in reverse breech extraction.Impact statementWhat is already known on the subject? IFH is an increasingly recognised, technically challenging complication of intrapartum CS. A recent report suggested that birth injuries associated with IFH are now as common as with shoulder dystocia. However, there is no consensus nor guidelines regarding the best practice for management or training.What do the results of this study add? This study demonstrates that IFH is poorly defined and commonly encountered by UK obstetricians. It highlights that IFH is not restricted to CS at full dilatation and reveals the ubiquity of the vaginal push method in UK practice. We found evidence that UK obstetricians are using techniques which have not been investigated and are not recommended for managing an IFH. Moreover, this survey is an eye-opener as to the paucity of training, highlighting that UK obstetric trainees are not adequately prepared to manage this emergency.What are the implications of these findings for clinical practice and/or further research? There is a pressing need to standardise the definition, guidance and training for IFH at CS. Further research should clarify the appropriate techniques for IFH and establish consensus for the best practice. An evidence-based simulation training package, which allows clinicians to learn and practice recognised disimpaction techniques is urgently required.

Comparison of outcomes at full-dilation cesarean section with and without the use of a fetal pillow device

OBJECTIVE

To identify whether use of the fetal pillow device resulted in a reduction in intraoperative complications, such as uterine incision extension, requirement for breech extraction, etc. Other maternal outcomes (duration of hospital stay, requirement for blood transfusion, and requirement for return to hospital or operating theatre) were also reviewed. Neonatal outcomes of APGAR-5, arterial pH, and requirement for intensive care admission were assessed.

METHODS

A retrospective cohort analysis was completed for fully dilated cesarean deliveries completed between January 2014 and December 2018 at Ipswich Hospital, Australia. In total, 174 patient records were identified (114 with pillow, 60 without). Logistic and linear regressions were used to assess the outcomes associated with fetal pillow use.

RESULTS

There were no significant differences in operative complications between the pillow and no-pillow groups (odds ratio [OR] 0.56, 95% confidence interval [CI] 0.26-1.22, P=0.146). Linear regression analysis showed a decrease in hospital length of stay (hours) (-9.4, 95% CI -17.80 to -0.99, P=0.029) and a higher neonatal arterial pH at delivery (0.06, 95% CI 0.03-0.09, P=0.0001) in the pillow group.

CONCLUSION

At full dilation cesarean, operative complications are not increased when employing the fetal pillow with maternal benefits of decreased hospitalization.

Difficult caesarean section: A literature review

BACKGROUND

Caesarean section (CS) is usually perceived as a simple and safe alternative to natural birth, but in some instances can be technically difficult with consequent health hazards for both the mother and the fetus. We have proposed an evidence-based literature review of the most common difficult CS scenarios, with the aim to provide useful information about their management, possible prevention and resolution of complications.

METHODS

We identified articles through a reserch in PubMed, Scopus, Web of Science and Ovid MEDLINE for studies published between 1979 and 2019. We included the best available evidence, such as RCTs, non-randomised controlled clinical trials, case-control studies, cohort studies, and case series. About sixty articles were included in this review, four hundred and thirty-six were excluded after reviewing the title or abstract or because they weren't in English.

FINDINGS

The possible causes of "difficult" caesarean sections were divided into four categories: difficult access to the lower uterine segment; complicated fetal extraction, laceration or organ damage and abnormal placentation.

CONCLUSIONS

Knowing in advance the potential technical difficulties and resulting risks allows the surgeon to plan appropriate strategies.

Subsequent Pregnancy Outcomes After Failed Vacuum-Assisted Delivery

OBJECTIVE

To examine trial of labor after cesarean delivery (TOLAC) success rates and its associated factors among women with a previous failed vacuum-assisted vaginal delivery.

METHODS

We conducted a retrospective cohort study. The study group comprised all women with a prior failed vacuum-assisted vaginal delivery who subsequently delivered from 2008 to 2017 at a university hospital.

RESULTS

Overall, 166 women with prior history of failed vacuum-assisted vaginal delivery delivered during the study period, with a median interdelivery interval of 28 (21-36) months. Of them, 53 (32%) had an elective repeat cesarean delivery, and 113 (68%) had a TOLAC. Although there were small statistical differences in the predelivery characteristics of the two groups, there were not clinically significant differences. Of the 113 women who underwent TOLAC in the subsequent pregnancy, the overall success rate was 67%. Neonatal 1- and 5-minute Apgar scores were lower among neonates born to women who experienced a failed TOLAC attempt compared with those who underwent successful TOLAC: 1-minute Apgar score less than 7 (6 [16%] vs 2 [3%], odds ratio [OR] 7.16, 95% CI 1.36-37.45, P=.01), 5-minute Apgar score less than 8 (3 [8%] vs 0 [0%], OR 15.5, 95% CI 1.78-308.7, P=.03). No events of obstetric anal sphincter injury, postpartum hemorrhage and uterine rupture were encountered among women who underwent TOLAC.

CONCLUSION

Trial of labor after cesarean delivery in women with a previous failed vacuum-assisted vaginal delivery appears to be associated with an acceptable success rate. These data should improve patient counseling and provide reassurance for those who wish to deliver vaginally after a previous failed vacuum-assisted vaginal delivery.

Neonatal subgaleal hemorrhage unrelated to assisted vaginal delivery: clinical course and outcomes

PURPOSE

The purpose of the study was to evaluate the occurrence of subgaleal hemorrhage (SGH) following non-assisted vaginal delivery (normal vaginal delivery or cesarean delivery), and to characterize associated factors, clinical course, and outcomes, compared to attempted assisted vaginal delivery (AVD)-associated SGH METHODS: A retrospective cohort study was conducted. All cases of SGH encountered following delivery of a singleton neonate at Hadassah, Hebrew University Medical Center during 2011-2018 were included. Maternal, fetal, intrapartum, and neonatal characteristics and outcomes were compared between AVD-related and non-AVD-related SGH groups.

RESULTS

The overall incidence of SGH was 4.5/1000 (369/82,256) singleton deliveries. The incidences of AVD- and non-AVD-related SGH were 44.6/1000 (350/7852) and 0.3/1000 (19/74,404) singleton deliveries, respectively. Ten (53%) of the 19 non-AVD-related SGH were diagnosed after vaginal delivery and 9 (47%) after an urgent cesarean section. SGH severity was mild, moderate, and severe in 68%, 16%, and 16% of the cases, respectively. SGH severity did not differ between the attempted AVD group and the non-AVD-related SGH group. A higher proportion of neonates with non-AVD SGH required phototherapy treatment than did those diagnosed with AVD-related SGH (56% vs. 24%, P = 0.003). Other neonatal outcomes, including Apgar scores, maximal bilirubin level, length of stay, and the rate of composite adverse outcomes, did not differ between the groups.

CONCLUSIONS

SGH, although rare, may be diagnosed after unassisted vaginal or cesarean delivery in the absence of an AVD attempt. We advocate continuing education for all medical staff who participate in peripartum and neonatal care, regarding the possible occurrence of non-AVD-related SGH.

Simulation of an impacted fetal head extraction during cesarean section: description of the creation and evaluation of a new training program

Background Although cesarean sections at full dilatation are increasing, training in delivering a deeply impacted fetal head is lacking among obstetricians. The purpose of the study was to implement and evaluate a theoretical and simulation-based training program for this obstetrical emergency. Methods We developed a training program consisting of a theoretical introduction presenting a clinical algorithm, developed on the basis of the available literature, followed by a simulation session. We used the Kirkpatrick's framework to evaluate the program. A questionnaire was distributed, directly before, immediately and 6 weeks after the training. Self-perceived competencies were evaluated on a 6-point Likert scale. Pre- and post-test differences in the Likert scale were measured with the Wilcoxon signed rank test. Additionally, the training sessions were video recorded and rated with a checklist in relation to how well the algorithm was followed. Results Eleven residents and eight senior physicians took part to the training. More than 40% of participants experienced a comparable situation after the course during clinical work. Their knowledge and self-perceived competencies improved immediately after the training program and 6 weeks later. Major improvements were seen in the awareness of the algorithm and in the confidence in performing the reverse breech extraction (14.3% of the participants felt confident with the maneuver in the pre-training assessment compared with 66.7% 6 week post-training). Conclusion Our theoretical and simulation-based training program was successful in improving knowledge and confidence of the participants in delivering a deeply impacted fetal head during a cesarean section performed at full dilation.

The impacted foetal head at caesarean section: incidence and techniques used in a single UK institution

An impaction of the foetal head at caesarean section is a topical concern in modern obstetric practice. The management options for this problem are well described but the incidence or even definition of impaction, is unknown. The primary aim of this study was to ascertain the incidence of impacted foetal head at CS in labour. This prospective study used data from all women undergoing CS during a 12-month period in a single unit. Following completion of all CS, the surgeon completed a questionnaire covering: cervical dilation at time of CS; if the surgeon felt there was a difficulty in delivering the foetal head as an indicator of impaction, as well as the other techniques utilised. Of 440 EMCS in labour, 18% (n = 81) reported a difficulty delivering the head, which was most common at cervical dilation ≥8 cm (n = 124, 48%). A difficulty with the delivery of the foetal head was associated with 36% increased measured blood loss. Impact statement What is already known on this subject? Impaction of the foetal head at a caesarean section is a recognised complication of CS in late labour but there are no reliable data on the incidence of the problem. It is poorly defined and yet many techniques and devices have been described to overcome this problem, however, optimal management remains uncertain. What do the results of this study add? The primary aim of this study was to determine the incidence of the impacted foetal head during CS in labour as determined by whether the surgeon experienced difficulty with delivery of the head. We report that at least some difficulty in delivering the foetal head at CS is common, and most often encountered when cervical dilation is ≥8 cm. When additional manoeuvres were required, the 'push' technique was exclusively adopted with implications for training. A difficulty in delivering the foetal head was associated with a 36% increase in the measured maternal blood loss. What are the implications of these findings for clinical practice and/or further research? Further multi-centre investigation is required to ascertain incidence of this obstetric problem with predicting factors determined. This work will inform decisions about the optimal management.

Comparison of 'push method' with 'Patwardhan's method' on maternal and perinatal outcomes in women undergoing caesarean section in second stage

A deeply impacted foetal head in a second stage caesarean section is associated with an increased risk of maternal and neonatal complications. For the present study, we compared the maternal and neonatal outcomes during the use of the 'Push method' and of 'Patwardhan's method' for a foetal head delivery in a second-stage caesarean section. This was a retrospective observational study involving 298 women who underwent a second stage caesarean section with a foetal head at or below the level of their ischial spines and was conducted in a tertiary teaching hospital in South India. The rates of uterine incision extension and other maternal complications were similar in both methods (24.9% vs. 26.0%, p = .850). The rates of neonatal sepsis (2.3% vs. 9.2%) and admission to neonatal intensive care unit (36.7% vs. 60.0%) were higher when Patwardhan's method was used. Although the maternal complications were similar, the use of Patwardhan's method resulted in higher rates of neonatal complications compared to the Push method during a second stage caesarean section. Future randomised, controlled studies comparing these two methods are needed to confirm their safety and benefits, prior to its routine use in second stage caesarean sections. Impact statement What is already known on this subject? Use of a second-stage caesarean section increases the risk of maternal and neonatal complications. A deeply engaged foetal head, along with the stretching and thinning of the lower uterine segment predisposes to these complications. The recent literature mainly compares the complication rates of the Push method to a Reverse breech extraction, with only small studies reporting the use of Patwardhan's technique for the delivery of a deeply engaged foetal head. What do the results of this study add? This study suggests that the use of either the Push method or of Patwardhan's method results in similar maternal complications such as extension of a uterine incision or postpartum haemorrhage. But neonatal complications such as neonatal sepsis (2.3% vs. 9.2%) and admission to neonatal intensive care unit (36.7% vs. 60.0%) were higher when Patwardhan's method was used. What are the implications of these findings for clinical practice and/or further research? The extension of uterine incision is similar in both methods; however, the neonatal complications were noted to be higher in those delivered with Patwardhan's technique. A future, randomised controlled trial comparing these two techniques is required to confirm the findings, before either of the methods are used in routine practice.

Unintended hysterotomy extension during caesarean delivery: risk factors and maternal morbidity

We conducted an observational retrospective cohort study to evaluate the risk factors and the maternal morbidity associated with unintended extensions of the hysterotomy during caesarean delivery. We evaluated 2707 women who underwent low-transverse caesarean deliveries in 2011 at an academic, tertiary-care hospital. Hysterotomy extensions were identified through operative reports. Of the 2707 caesarean deliveries, 392 (14.5%) had an unintended hysterotomy extension. On the multivariable regression modelling, neonatal weight (OR 1.42; 95%CI 1.17-1.73), the arrest of labour [first-stage arrest (2.42; 1.73-3.38); second-stage arrest (5.54; 3.88-7.90)] and a non-reassuring foetal status (1.65; 1.20-2.25) were significantly associated with hysterotomy extensions. Hysterotomy extensions were significantly associated with an increased morbidity including an estimated blood loss >1200 millilitres (2.06; 1.41-3.02), a decline in postoperative haemoglobin ≥3.7 g/dL (2.07; 1.35-3.17), an evaluation for lower urinary tract injury (5.58; 3.17-9.81), and a longer operative time (8.11; 6.33-9.88). Based on these results, we conclude that unintended hysterotomy extensions significantly increase the maternal morbidity of caesarean deliveries. Impact statement What is already known on this subject? Maternal morbidity associated with caesarean delivery (CD) is significantly greater than that in vaginal delivery. Unintended extensions of the hysterotomy occur in approximately 4-8% of CDs and are more common after a prolonged second stage of labour. The morbidity associated with hysterotomy extensions has been incompletely evaluated. What do the results of this study add? We demonstrate a rate of hysterotomy extension in a general obstetric population of approximately 15%, which is higher than previously reported estimates, and represents a potential doubling of the rate of the unintended hysterotomy extensions in recent years. The most significant risk factor for a hysterotomy extension was a second-stage labour arrest with a fourfold increase in the frequency of extensions. A hysterotomy extension is a significant independent risk factor for an intraoperative haemorrhage, a drop in postoperative haemoglobin, an intraoperative evaluation for lower urinary tract injury, and longer CD operative times. What are the implications of these findings for clinical practice and/or further research? A second-stage arrest is a strong independent risk factor for a hysterotomy extension. Recent re-evaluations of the labour curve that extend the second stage of labour will likely increase the frequency of CDs performed after a prolonged second stage. In these scenarios, obstetricians should be prepared for an unintended hysterotomy extension and for the possibility of a longer procedure with the increased risks of blood loss and the need for evaluation of the lower urinary tract.

Cesarean delivery in the second stage of labor and the risk of subsequent premature birth

BACKGROUND

Cesarean delivery is being increasingly used by obstetricians for indicated deliveries in the second stage of labor. Unplanned extension of the uterine incision involving the cervix often occurs with these surgeries. Therefore, we hypothesized that cesarean delivery in the second stage of labor may increase the rate of subsequent spontaneous premature birth.

OBJECTIVE

We sought to determine if cesarean delivery in the late first stage of labor or in the second stage of labor increases the risk of a subsequent spontaneous preterm birth.

STUDY DESIGN

We conducted a retrospective cohort study of matched first and second births from a large Canadian perinatal database. The primary outcomes were spontaneous premature birth <37 and <32 weeks of gestation in the second birth. The exposure was stage of labor and cervical dilation at the time of the first cesarean delivery. The protocol and analysis plan was registered prior to obtaining data at Open Science Foundation.

RESULTS

In total, 189,021 paired first and second births were identified. The risk of spontaneous preterm delivery <37 and <32 weeks of gestation in the second birth was increased when the first birth was by cesarean delivery in the second stage of labor (relative risk, 1.57; 95% confidence interval, 1.43-1.73 and relative risk, 2.12; 95% confidence interval, 1.67-2.68, respectively). The risk of perinatal death in the second birth, excluding congenital anomalies, was also correspondingly increased (relative risk, 1.44; 95% confidence interval, 1.05-1.96).

CONCLUSION

Cesarean delivery in second stage of labor was associated with a 2-fold increase in the risk of spontaneous preterm birth <32 weeks of gestation in a subsequent birth. This information may inform management of operative delivery in the second stage.

Sonographic Findings and Diagnostic Pitfalls in Evaluation for Uterine Rupture in a Case of Fetal Demise and Prior Cesarean Delivery of Unknown Type

A 38-week pregnant patient with history of cesarean delivery was admitted to the hospital for induction of labor after diagnosis of fetal demise. When the clinical picture became concerning for uterine scar dehiscence, an ultrasound was ordered. After targeted ultrasound of the lower uterine segment, the sonographer initially reported thin but intact lower uterine segment and normal positioning of the fetus. By keeping a high level of suspicion, the radiologist analyzed the images submitted and found other clues suggesting possible dehiscence or rupture. Additional images were then obtained, ultimately demonstrating uterine rupture with fetus external to uterus.