Evolving Evidence Since the Term Breech Trial: Canadian Response, European Dissent, and Potential Solutions

Comparing forces on the fetal neck in breech delivery in lithotomy versus all-fours position: a simulation model

PURPOSE

To measure forces applied to the fetal neck, in a simulation model for breech delivery, in both lithotomy versus all-fours position.

METHODS

We used a Laerdal SimMom simulator and a Birthing Baby together with PROMPT Flex Software. The descent of the fetus was accomplished using the Automatic Delivery Module 2. The baby was always in breech position; the SimMom in either all-fours or lithotomy positions. Sensors were located inside the fetal neck region to simulate forces applied to the plexus.

RESULTS

The lowest force on the fetal neck region was recorded for the delivery in all-fours position without further maneuvers (mean force 58.70 Newton, standard deviation 2.54 N). As weight was added to the baby, the force increased (i.e. + 500 g, mean force 71.8 N, SD 3.08 N, p < 0.001). Delivery in lithotomy position resulted in a mean force of 81.56 N (SD 19.55 N). The force significantly increased in case of delivery of the head without assistance from contractions (mean force 127.93 N, SD 23.10 N). In all-fours position, the delivery of the fetal head from pelvic floor level without contractions (Frank's Nudge maneuver) resulted in a mean force of 118.45 N (SD 15.48 N, p = 0.02). Maneuvers for shoulder dystocia (the inverted type that can occur during breech delivery) led to significantly higher mean forces independent from birthing positions.

CONCLUSION

Breech delivery in all-fours position was associated with the lowest force acting on the fetal neck in our simulation model.

Combined Assessment of the Obstetrical Conjugate and Fetal Birth Weight Predicts Birth Mode Outcome in Vaginally Intended Breech Deliveries of Primiparous Women-A Frabat Study

(1) Background: Guidelines on vaginal breech delivery require birth weight restrictions and neglect the impact of pelvic measurements despite contradicting evidence. There is a great need for more evidence on delivery outcome predicting factors for patients counselling. (2) Methods: We performed a prospective cohort study on 748 primiparous women intending vaginal breech birth and analyzed combined influence of fetal birth weight (BW) and the obstetric conjugate (conjugate vera obstetrica, CVO) on delivery outcome. (3) Results: We generated a BW/CVO ratio and devided our study cohort at median (257.8 g/cm) into a low ratio group (LR, with low birth weight and wide obstetric conjugate) and a high ratio group (HR, high birth weight and narrow obstetric conjugate). Cesarean section (CS) rate was significantly higher in HR (50.3%) as compared to LR (28.3%, p < 0.0001). Fetal morbidity was not different. In vaginally completed deliveries duration of birth was significantly longer in vHR (557 min) as in vLR (414 min, p < 0.001). Manual assistance to deliver the arms (‘Louwen maneuver’) positively correlated with birth weight (r2 = 0.215; p = 0.005) and the BW/CVO ratio (r2 = 0.0147; p = 0.02). (4) Conclusions: A high fetal birth weight combined with a tiny CVO predicts higher cesarean section probability, longer birth duration and the necessity to perform arm delivery assistance. Birth weight and pelvic measurements should be topics of great importance in patients counselling.

Impact of implementation of a breech clinic in a tertiary hospital

BACKGROUND

The incidence of breech presentation in single pregnancies at term is between three to 5 %. In order to support eligible women in their choice of mode of delivery, a dedicated breech clinic with a care pathway was developed in December 2015 in a tertiary referral centre in Brussels. The primary objective of this study was to evaluate the vaginal birth rate before and after the introduction of a dedicated breech clinic. The secondary objective was to compare the early neonatal outcomes before and after the breech clinic was introduced.

METHODS

This was a single centre retrospective and prospective study. The inclusion criteria were term (from 37 weeks), singleton fetus and breech presentation at delivery. The exclusion criteria were suspected intrauterine growth restriction, severe fetal malformations and intrauterine fetal demise. We used a composite outcome as an indicator of neonatal morbidity and mortality.

RESULTS

After the introduction of the breech clinic, we observed a significant increase in planned vaginal delivery from 7.4% (12/162) to 53.0% (61/115) (OR: 13.5; 95% CI: 6.7-27.0). The effective vaginal breech delivery rate (planned and unexpected) significantly increased from 4.3% (7/162) pre-implementation of breech clinic to 43.5% (50/115) post-implementation (OR: 17.0; 95% CI: 7.3-39.6). Neonatal outcomes were not statistically different between the before and after periods.

CONCLUSION

The introduction of a dedicated breech clinic has led to an increase in vaginal deliveries for breech babies without adversely affecting neonatal outcomes.

Vaginal breech delivery of pregnancy before and after the estimated due date-A prospective cohort study

INTRODUCTION

3-4% of pregnant women present with a fetal breech position at term. National societies regard vaginal breech delivery as a safe option, but only for a specific and thoroughly counseled group of patients. To avoid adverse outcome, many practitioners recommend elective cesarean section once their patients go past the estimated due date. Since encompassing evidence is missing, the evaluation on this common clinical practice is needed.

OBJECTIVE

This study compares the short-term maternal and fetal outcome in intended vaginally breech deliveries before the estimated due date (until 40 0/7 weeks of gestation) to the outcome of deliveries carried out past the estimated due date (later than 40 0/7 weeks of gestation).

METHODS

This prospective cohort study includes 827 women who presented for an intended vaginal breech delivery of a singleton at our perinatal center between January 2010 and December 2016.

RESULTS

447 patients (54%) delivered before or at their estimated due date, 380 (46%) of pregnancies continued after the estimated due date. Comparing both groups, no significant difference in maternal and neonatal short-term mortality and morbidity was found. The rate of caesarian sections was increased in the group of patients, who delivered later than 40 1/7 weeks of gestation. Here, the likelihood for delivery maneuvers was also increased.

CONCLUSION

This study provides evidence, that an elective cesarean section for breech presentations at term is not obligatory when the estimated due date has passed in singleton pregnancy.

MRI-based pelvimetric measurements as predictors for a successful vaginal breech delivery in the Frankfurt Breech at term cohort (FRABAT)

OBJECTIVES

The purpose of this study was to investigate the role of the maternal pelvis, assessed by MRI pelvimetry in nulliparous women expecting a term fetus in breech presentation, to predict a successful and safe vaginal birth.

STUDY DESIGN

In this monocentric and anonymized cohort study, we enrolled 367 nulliparous women with breech presentation at 39⁺⁰ to 41⁺⁰ weeks of gestation during a period of 8 years at the University Women's Hospital in Frankfurt/Main. Pelvic measurements were obtained by standard MRI imaging. We correlated the obstetric conjugate, the pubic angle and the distance between the ischial tuberosities (intertuberous distance) with the maternal and fetal outcomes of vaginally intended breech births. The data was evaluated using logistic regression analysis.

RESULTS

241 of 367 participants (65.7%) experienced a successful vaginal delivery whereas 126 patients (34.3%) were subjected to secondary cesarean section. An increasing obstetric conjugate was significantly associated with an increasing rate of successful vaginal deliveries. No significant correlation of the intertuberous distance and the pubic angle with the mode of delivery could be shown. Although statistically not significant, we were able to define cut-off values of 10.9 cm in the intertuberous distance and 70° in the pubic angle; below these values, no successful vaginal delivery was recorded. No significant differences in the short-term outcomes were seen between the neonates of the vaginal delivery and the cesarean section groups. Inter- and intraobserver variability showed excellent reproducibility for all MRI parameters.

CONCLUSION

The obstetric conjugate correlates with the rate of vaginal deliveries in nulliparous women at term and can be used as a useful criterion for pre-selection and counseling of women with breech presentation and the desire for a vaginal delivery.

Induction of labor in breech presentation at term: a retrospective cohort study

OBJECTIVE

To compare the outcome of two methods of labor induction and spontaneous onset of labor in breech presentation at term.

MATERIAL

A retrospective study between 2003 and 2012. We compare obstetric (indication of induction, Bishop score, cesarean rate) and perinatal outcomes (Apgar score, umbilical artery pH, base excess ≤-12 mmol/L, admission to neonatal unit) between prostaglandins and oxytocin. We also compare labor induction versus spontaneous onset of labor.

RESULTS

Of the 1684 breech deliveries, we carried out labor induction in 221 cases (76% with prostaglandins, 24% with oxytocin). The prostaglandins group had significantly lower Bishop scores and the time for induction phase was significantly higher. There were no differences in cesarean rate between both methods of induction or spontaneous onset of labor. The prostaglandins group had higher rates of base excess ≤-12 mmol/L. Compared with spontaneous onset of labor in breech presentation, induction had significant lower rates of newborn weight and higher rates of admission to the neonatal unit.

CONCLUSIONS

Induction of labor in breech presentation at term is a reasonable and effective option after a careful selection of cases. It was not associated with an increase of perinatal morbidity or cesarean rate compared with spontaneous onset of labor.

The Ten-Group Robson Classification: A Single Centre Approach Identifying Strategies to Optimise Caesarean Section Rates

Caesarean section (CS) rates have been increasing worldwide and have caused concerns. For meaningful comparisons to be made World Health Organization recommends the use of the Ten-Group Robson classification as the global standard for assessing CS rates. 2625 women who birthed over a 12-month period were analysed using this classification. Women with previous CS (group 5) comprised 10.9% of the overall 23.5% CS rate. Women with one previous CS who did not attempt VBAC contributed 5.3% of the overall 23.5% CS rate. Second largest contributor was singleton nulliparous women with cephalic presentation at term (5.1% of the total 23.5%). Induction of labour was associated with higher CS rate (groups 1 and 3) (24.5% versus 11.9% and 6.2% versus 2.6%, resp.). For postdates IOL we recommend a gatekeeper booking system to minimise these being performed <41 weeks. We suggest setting up dedicated VBAC clinic to support for women with one previous CS. Furthermore review of definition of failure to progress in labour not only may lower CS rates in groups 1 and 2a but also would reduce the size of group 5 in the future.

This baby is not for turning: Women's experiences of attempted external cephalic version

BACKGROUND

Existing studies regarding women's experiences surrounding an External Cephalic Version (ECV) report on women who have a persistent breech post ECV and give birth by caesarean section, or on women who had successful ECVs and plan for a vaginal birth. There is a paucity of understanding about the experience of women who attempt an ECV then plan a vaginal breech birth when their baby remains breech. The aim of this study was to examine women's experience of an ECV which resulted in a persistent breech presentation.

METHODS

A qualitative descriptive exploratory design was undertaken. In-depth semi-structured interviews were conducted and analysed thematically.

RESULTS

Twenty two (n = 22) women who attempted an ECV and subsequently planned a vaginal breech birth participated. Twelve women had a vaginal breech birth (55 %) and 10 (45 %) gave birth by caesarean section. In relation to the ECV, there were five main themes identified: 'seeking an alternative', 'needing information', 'recounting the ECV experience', 'reacting to the unsuccessful ECV' and, 'reflecting on the value of an ECV'.

CONCLUSIONS

ECV should form part of a range of options provided to women, rather than a default procedure for management of the term breech. For motivated women who fit the safe criteria for vaginal breech birth, not being subjected to a painful experience (ECV) may be optimal. Women should be supported to access services that support vaginal breech birth if this is their choice, and continuity of care should be standard practice.

Management of breech presentation at term: a retrospective cohort study of 10 years of experience

OBJECTIVE

To evaluate the impact of management of childbirth (external cephalic version (ECV) plus planned vaginal delivery (PVD)) of breech presentation at term (⩾37 weeks of gestation).

STUDY DESIGN

This retrospective cohort study was based on data collected of singleton breech presentations at term in the Obstetrics and Gynaecology Service, Cruces University Hospital (Biscay, Spain), from January 2003 to December 2012.

RESULT

We attended 2377 singleton breech pregnancies at term. We attended 1684 singleton breech term deliveries, attempting vaginal delivery after selection in 52.9% of cases and were successful in 57.5% of attempts. A total of 1360 ECV were attempted, with a success rate of 50.3% of those attempted. The use of ECV has decreased the rate of breech presentation at delivery by 39.0%, the rate of breech presentation as a caesarean section (CS) indication by 47.1% (CS due to breech presentation/total of CS) and the rate of CS for breech presentation out of the total of deliveries by 39.1% (CS due to breech presentation/total of deliveries). Early postnatal parameters (5-min Apgar score, umbilical cord arterial pH and acid-base analysis) were significantly lower following PVD compared with planned CS for breech presentation. However, we did not find any differences in the rates of admissions to the neonatal unit or neonatal mortality.

CONCLUSION

Management of breech presentation with a protocol that includes ECV, careful selection criteria and active management of vaginal delivery achieve a great decrease in the rate of CS for breech presentation.

Does pregnancy and/or shifting positions create more room in a woman's pelvis?

OBJECTIVE

The purpose of this study was to assess the impact of different positions on pelvic diameters by comparing pregnant and nonpregnant women who assumed a dorsal supine and kneeling squat position.

STUDY DESIGN

In this cohort study from a tertiary referral center in Germany, we enrolled 50 pregnant women and 50 nonpregnant women. Pelvic measurements were obtained with obstetric magnetic resonance imaging pelvimetry with the use of a 1.5-T scanner. We compared measurements of the depth (anteroposterior (AP) and width (transverse diameters) of the pelvis between the 2 positions.

RESULTS

The most striking finding was a significant 0.9-1.9 cm increase (7-15%) in the average transverse diameters in the kneeling squat position in both pregnant and nonpregnant groups. The average bispinous diameter in the pregnant group increased from 12.6 cm ± 0.65 cm in the supine dorsal to 14.5 cm ± 0.64 cm (P < .0001) in the kneeling squat; in the nonpregnant group the increase was from 12 cm ± 0.76 cm to 13.9 cm ± 1.04 cm (P < .0001). The average bituberous diameter in the pregnant group increased from 13.6 cm ± 0.93 cm in the supine dorsal to 14.5 cm ± 0.83 cm (P < .0001) in the kneeling squat position; in the nonpregnant women the increase was from 12.6 cm ± 0.92 cm to 13.5 cm ± 0.88 cm (P < .0001).

CONCLUSION

A kneeling squat position significantly increases the bony transverse and anteroposterior dimension in the mid pelvic plane and the pelvic outlet. Because this indicates that pelvic diameters change when women change positions, the potential for facilitation of delivery of the fetal head suggests further research that will compare maternal delivery positions is warranted.

Vaginal breech delivery: results of a prospective registration study

BACKGROUND

Most countries recommend planned cesarean section in breech deliveries, which is considered safer than vaginal delivery. As one of few countries in the western world Norway has continued to practice planned vaginal delivery in selected women. The aim of this study is to evaluate prospectively registered neonatal and maternal outcomes in term singleton breech deliveries in a Norwegian hospital during a ten years period. We aim to compare maternal and neonatal outcomes in term breech pregnancies subjected either to planned vaginal or elective cesarean section.

METHODS

A prospective registration study including 568 women with term breech deliveries (>37 weeks) consecutively registered at Sorlandet Hospital Kristiansand between 2001 and 2011. Fetal and maternal outcomes were compared according to delivery method; planned vaginal delivery versus planned cesarean section.

RESULTS

Of 568 women, elective cesarean section was planned in 279 (49%) cases and vaginal delivery was planned in 289 (51%) cases. Acute cesarean section was performed in 104 of the planned vaginal deliveries (36.3%). There were no neonatal deaths. Two cases of serious neonatal morbidity were reported in the planned vaginal group. One infant had seizures, brachial plexus injury, and cephalhematoma. The other infant had 5-minutes Apgar < 4. Twenty-nine in the planned vaginal group (10.0%) and eight in the planned cesarean section group (2.9%) (p < 0.001) were transferred to the neonatal intensive care unit. However, only one infant was admitted for ≥4 days. According to follow-up data (median six years) none of these infants had long-term sequelae. Regarding maternal morbidity, blood loss was the only variable that was significantly higher in the planned cesarean section group versus in the vaginal delivery group (p < 0.001).

CONCLUSIONS

Strict guidelines were followed in all cases. There were no neonatal deaths. Two infants had serious neonatal morbidity in the planned vaginal group without long-term sequelae.

Use of a Classification Tool to Determine Groups of Women That Contribute to the Cesarean Section Rate: Establishing a Baseline for Clinical Decision Making and Quality Improvement

OBJECTIVE:To identify the groups of women who are the largest contributors to the cesarean section rate at a maternity facility in South East Queensland, Australia. Examining the characteristics of these women will allow the development of unit-focused initiatives aimed at reducing cesarean sections in these groups of women.

METHOD:A modified version of the Robson Ten Group Classification System was identified as the most appropriate tool to determine cesarean section rates in different groups of women. A prospective clinical audit was then carried out during a 6-month period in 2010 using the tool.

FINDINGS:The Robson Ten Group Classification System identified that planned repeat cesarean section was the largest contributor to the cesarean rate. This was followed by women having their first baby, women having an induction, and women who have a breech presentation at term.

CONCLUSIONS AND IMPLICATIONS:The Robson classification tool was useful in identifying groups of women at risk of a cesarean section. Unit-specific strategies can now be developed and implemented in an effort to lower the rate. These include increasing the vaginal birth after cesarean rate, the uptake of external cephalic version, supporting nonintervention birth environments, and implementing models of care where clinicians are skilled in facilitating normal birth. The value of using such a tool is the ability to monitor change over time as well as facilitating the comparison of data between units of a similar nature.