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

Maternal and neonatal outcomes associated with breech presentation in planned community (home and birth center) births in the United States: A prospective observational cohort study

OBJECTIVE

Investigate maternal and neonatal outcomes associated with breech presentation in planned community births in the United States, including outcomes associated with types of breech presentation (i.e., frank, complete, footling/kneeling).

DESIGN

Secondary analysis of prospective cohort data from a national perinatal data registry (MANA Stats).

SETTING

Planned community birth (homes and birth centers), United States.

SAMPLE

Individuals with a term, singleton gestation (N = 71,943) planning community birth at labor onset.

METHODS

Descriptive statistics to calculate associations between types of breech presentation and maternal and neonatal outcomes.

MAIN OUTCOME MEASURES

Maternal: intrapartum/postpartum transfer, hospitalization, cesarean, hemorrhage, severe perineal laceration, duration of labor stages and membrane rupture Neonatal: transfer, hospitalization, NICU admission, congenital anomalies, umbilical cord prolapse, birth injury, intrapartum/neonatal death.

RESULTS

One percent (n = 695) of individuals experienced breech birth (n = 401, 57.6% vaginally). Most fetuses presented frank breech (57%), with 19% complete, 18% footling/kneeling, and 5% unknown type of breech presentation. Among all breech labors, there were high rates of intrapartum transfer and cesarean birth compared to cephalic presentation (OR 9.0, 95% CI 7.7-10.4 and OR 18.6, 95% CI 15.9-21.7, respectively), with no substantive difference based on parity, planned site of birth, or level of care integration into the health system. For all types of breech presentations, there was increased risk for nearly all assessed neonatal outcomes including hospital transfer, NICU admission, birth injury, and umbilical cord prolapse. Breech presentation was also associated with increased risk of intrapartum/neonatal death (OR 8.5, 95% CI 4.4-16.3), even after congenital anomalies were excluded.

CONCLUSIONS

All types of breech presentations in community birth settings are associated with increased risk of adverse neonatal outcomes. These research findings contribute to informed decision-making and reinforce the need for breech training and research and an increase in accessible, high-quality care for planned vaginal breech birth in US hospitals.

Mechanics of vaginal breech birth: Factors influencing obstetric maneuver rate, duration of active second stage of labor, and neonatal outcome

BACKGROUND

We investigated possible parameters that could predict the need for obstetric maneuvers, the duration of the active second stage of labor (i.e., the duration of active pushing), and short-term neonatal outcome in vaginal breech births.

MATERIALS AND METHODS

We performed a retrospective analysis of 268 successful singleton vaginal breech births in women without previous vaginal births from January 2015 to August 2022. Multivariable regression was used to investigate associations between maternal and fetal characteristics (including antepartum magnetic resonance (MR) pelvimetry) with obstetric maneuvers, the duration of active second stage of labor, pH values, and admission to the neonatal unit. Models for the prediction of obstetric maneuvers were built and internally validated.

RESULTS

Obstetric maneuvers were performed in a total of 130 women (48.5%). A total of 32 neonates (11.9%) had to be admitted to the neonatal unit. The intertuberous distance (ITD) (p < 0.001), epidural analgesia (p < 0.001), and birthweight (p = 0.026) were associated with the duration of active second stage of labor. ITD (p = 0.028) and birthweight (p = 0.011) were also independently associated with admission to the neonatal unit, while pH values below 7.10 dropped significantly (p = 0.0034) if ITD was ≥13 cm. Furthermore, ITD (p < 0.001) and biparietal diameter (p = 0.002) were independent predictors for obstetric maneuvers.

CONCLUSIONS

ITD is independently associated with the duration of active second stage of labor. Thus, it can predict suboptimal birth mechanics in the last stage of birth, which may lead to the need for obstetric maneuvers, lower arterial pH values, and admission to the neonatal unit. Consequently, MR pelvimetry gives additional information for practitioners and birthing people preferring a vaginal breech birth.

Introducing the fragility index-A case study using the Term Breech Trial

The fragility index (FI) is a sensitivity analysis of the statistically significant result of a clinical study. It is the number of hypothetical changes in the primary event of one of the two cohorts in a 1-to-1 comparative trial to render the statistically significant result non-significant (ie, to alter the P-value from ≤0.05 to >0.05). The FI can be compared with the patient drop-out rates and protocol violations, which, if much higher than the FI, may arguably suggest less robustness/stability of the trial's results. To illustrate the concept, we have chosen the Term Breech Trial (TBT) as a case study. The TBT results favor planned cesarean birth, as opposed to planned vaginal delivery, in the term singleton fetus with breech presentation. Our analysis shows that the FI of the TBT is 21, which is small in comparison to the number (hundreds) of protocol violations present. Some experts have suggested the inclusion of the FI in data analysis and subsequent discussion of clinical trial data. Routine use of such a metric may be valuable in encouraging readers to maintain a healthy degree of skepticism, especially when interpreting trial results which may directly influence clinical practice.

Factors associated with cesarean birth in nulliparous women: A multicenter prospective cohort study

BACKGROUND

There is widespread concern around the rising rates of cesarean births (CBs), especially among first-time mothers, despite evidence suggesting increased morbidities after birth by cesarean. There are uncertainties around factors associated with rising rates of CBs among first-time mothers in Ireland, and insight into these is essential for understanding the rising trend in CBs. Therefore, this study aimed to identify the factors associated with CBs in nulliparous women.

METHODS

A prospective cohort study was conducted in three maternity hospitals in the Republic of Ireland between 2012 and 2017. Data were collected from 3047 nulliparous women using self-administered surveys antenatally and at 3 months postpartum and from consenting women's hospital records (n = 2755) and analyzed using the Poisson regression to assess associations between demographic and clinical factors and the main outcome measures, planned and unplanned CBs.

RESULTS

Common risk factors for planned and unplanned CBs were being aged ≥40 years, being in private care, multiple pregnancy, and fetus in breech or other malpresentations. An unplanned CB occurred for 22.43% (n = 377/1681) of women who did not have induction of labor (IOL) or who had IOL with no epidural, but the risk was about twice as high for women who had IOL and epidural.

CONCLUSIONS

Findings confirm multifactorial reasons for CB and the challenge of reversing the increasing CB rate if maternal age, overweight/obesity, infertility treatment, multiple pregnancy, and preexisting hypertension in Ireland continue to increase. There is a need to address prelabor interventions, especially IOL combined with epidural analgesia with respect to unplanned CB.

Neonatal admission rate after vaginal breech delivery

OBJECTIVES

The safest mode of delivery for fetuses in breech presentations is still an ongoing debate. The aim of this study was to analyze neonatal admission rates after vaginal breech delivery and compare it to other modes of delivery in order to counsel pregnant women with breech presentation adequately.

METHODS

We performed a retrospective monocentric analysis of all deliveries with singleton pregnancies in breech presentation > 36.0 weeks of gestation between 01/2018-12/2019. Short-term neonatal morbidity data was collected for vaginal delivery and primary as well as secondary cesarean sections from breech presentations.

RESULTS

A total of n=41/482 (8.5%) neonates had to be admitted to NICU: vaginal breech delivery n=18/153 (11.8%), primary cesarean section n=9/101 (8.9%, OR 0.73; CI 0.32-1.70; p=0.47), secondary cesarean section n=10/76 (13.2%, OR 1.14; CI 0.50-2.60, p=0.76) and vaginal vertex delivery n=4/152 (2.6%, OR 0.20; CI 0.06-0.51; p=0.005). There was no significant difference in transfer to NICU between all breech position delivery modes. Despite significantly lower pH and 5' APGAR values after vaginal delivery, neonates delivered by primary cesarean section and NICU admission had to be treated there significantly longer (mean 80.9 vs. 174.0 h). No significant difference in terms of ventilation parameters and infections were found between the vaginal delivery, primary and secondary cesarean section from breech presentation.

CONCLUSIONS

Vaginal breech delivery does not result in a higher neonatal admission rate in comparison to primary and secondary section. In contrast, there is a shorter NICU duration in case of neonatal admission after vaginal delivery.

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.