[Impact of the external cephalic version on the obstetrical prognosis in a team with a high success rate of vaginal delivery in breech presentation]

[Impact of a service protocol on the practice of vaginal delivery of breech presentations at term]

OBJECTIVES

The delivery of breech presentations remains controversial. Our study analysed the impact of a service protocol on the proportion of planned vaginal delivery and its success. Immediate neonatal morbidity and factors that may influence the success of vaginal delivery were studied.

METHODS

Retrospective study, between 2009 and 2020 at the CHRU of Limoges, type 3 maternity hospital, on patients with a breech foetus at term. The proportion of planned vaginal delivery and the rate of effective vaginal delivery were compared before/after 2015. Neonatal morbidity was compared for planned vaginal delivery and planned cesarean delivery groups.

RESULTS

We included 923 patients. The rate of planned vaginal delivery was significantly higher after 2015 from 5.2% to 19% (P<0.001), with a success rate increasing from 60% to 82.1% (P=0.06). The rate of vaginal breech deliveries significantly increased from 3.8% to 17% (P<0.001). We found significantly more newborns with moderate acidosis when a vaginal delivery was attempted (P<0.001). The success of vaginal delivery was correlated to the Magnin index (P=0.044), to gestational age (P=0.037), and to multiparity (OR 3.78 95% CI [1.42-10.03] P=0.006).

CONCLUSION

Our study demonstrates the benefits of setting up a service protocol for the practice of breech vaginal delivery.

Influence of the external cephalic version attempt on the Cesarean section rate: experience of a type 3 maternity hospital in France

PURPOSE

To define the effects of attempted external cephalic version (ECV) in a low-risk population for breech delivery in a maternity hospital where breech vaginal delivery is widely practiced.

MATERIALS AND METHODS

Retrospective exposed-unexposed study including 204 patients presented with a live singleton fetus breech presentation on third-trimester ultrasound and who delivered at Reims University Hospital between January 1st, 2013 and July 1st, 2018.

RESULTS

121 patients received ECV. Cesarean section rate was lower (OR with no adjustment 0.42 [0.24-0.76] p = 0.004) but without significant difference in the exposed patients after adjustment. This difference was significant between exposed and unexposed patients in the subgroup of 51 primiparous (OR = 0.14 [0.04-0.52] p = 0.002) and 51 multiparous (OR = 0.26 [0.08-0.89] p = 0.028) but not in the subgroup of 102 nulliparous. There was no difference in fetal impact other than neonatal management in the delivery room, which is less needed in exposed primiparous women. Attempted ECV significantly decreased the breech rate (72.5 vs 100%, p < 0.001). There were 7 (5.79%) complications. Three factors favored success: high uterine height (p = 0.011), a non-elevated BMI (p = 0.006) and an earlier term at ECV (p = 0.003).

CONCLUSION

The attempt of ECV in the Reims University Hospital does not significantly reduce the Cesarean section rate and has no effect on neonatal status.

Revisiting the management of term breech presentation: a proposal for overcoming some of the controversies

Background

The debate surrounding the management of term breech presentation has excessively focused on the mode of delivery. Indeed, a steady decline in the rate of vaginal breech delivery has been observed over the last three decades, and the soundness of the vaginal route was seriously challenged at the beginning of the 2000s. However, associations between adverse perinatal outcomes and antenatal risk factors have been observed in foetuses that remain in the breech presentation in late gestation, confirming older data and raising the question of the role of these antenatal risk factors in adverse perinatal outcomes. Thus, aspects beyond the mode of delivery must be considered regarding the awareness and adequate management of such situations in term breech pregnancies.

Main body

In the context of the most recent meta-analysis and with the publication of large-scale epidemiologic studies from medical birth registries in countries that have not abruptly altered their criteria for individual decision-making regarding the breech delivery mode, the currently available data provide essential clues to understanding the underlying maternal-foetal conditions beyond the delivery mode that play a role in perinatal outcomes, such as foetal growth restriction and gestational diabetes mellitus. In view of such data, an accurate evaluation of these underlying conditions is necessary in cases of persistent term breech presentation. Timely breech detection, estimated foetal weight/growth curves and foetal/maternal well-being should be considered along with these possible antenatal risk factors; a thorough analysis of foetal presentation and an evaluation of the possible benefit of external cephalic version and pelvic adequacy in each specific situation of persistent breech presentation should be performed.

Conclusion

The adequate management of term breech pregnancies requires screening and the efficient identification of breech presentation at 36 weeks of gestation, followed by thorough evaluations of foetal weight, growth and mobility, while obstetric history, antenatal gestational disorders and pelvis size/conformation are considered. The management plan, including external cephalic version and follow-up based on the maternal/foetal condition and potentially associated disorders, should be organized on a case-by-case basis by a skilled team after the woman is informed and helped to make a reasoned decision regarding delivery route.

Effectiveness of nitrous oxide in external cephalic version on success rate: A randomized controlled trial

INTRODUCTION

Approximately 4% of singleton pregnancies at term are in breech presentation. External cephalic version (ECV) can reduce the risks of noncephalic birth and cesarean delivery, but this maneuver can be painful. Our aim was to analyze the effect of administering inhaled nitrous oxide for analgesia on the ECV success rate.

MATERIAL AND METHODS

This prospective, randomized, single-blind, controlled trial included women with singleton pregnancies in breech presentation at term who were referred for ECV in a tertiary care center. Women were assigned according to a balanced (1:1) restricted randomization design to inhale either nitrous oxide (N₂ O) in a 50:50 mix with oxygen or medical air during the procedure. The main outcomes reported are the ECV success rate, degree of pain, adverse event rate, and women's satisfaction.

TRIAL REGISTRATION

ClinicalTrials.gov Identifier: NCT01948115.

RESULTS

The study included 150 women (nitrous oxide group: n = 74; medical air: n = 76). Inhaled nitrous oxide was not associated with a higher ECV success rate than medical air (24.3 vs 19.7%, P = 0.51). Among parous women (n = 34 in each group), the ECV success rate appeared higher in the nitrous oxide group, respectively 47.1% (n = 16) vs 23.5% (n = 8) (P = 0.042). Neither the median pain level nor adverse event rates differed significantly in women with inhaled nitrous oxide compared with medical air.

CONCLUSIONS

Use of an equimolar mixture of oxygen and nitrous oxide during ECV appears safe. Although it does not seem to change the overall success rate, it may increase success in parous women.