The impact of a routine late third trimester growth scan on the incidence, diagnosis, and management of breech presentation in Oxfordshire, UK: A cohort study

Consensus-based recommendations for the care of women with a breech presenting fetus

OBJECTIVE

To establish consensus related to aspects of breech presentation and care.

DESIGN

A multinational, three round e-Delphi study.

PARTICIPANTS

A panel of 15 midwives, four obstetricians and an academic with knowledge and/or experience of caring for women with a breech presenting fetus.

METHODS

An initial survey of 45 open-ended questions. Answers were coded and amalgamated to form 448 statements in the second round and three additional statements in the third round. Panellists were asked to provide their level of agreement for each statement using a 5-point Likert scale. Consensus was deemed met if 70% of panellists responded with strongly agree to somewhat agree, or strongly disagree to somewhat disagree after the second round.

FINDINGS

Results led to the development of a consensus-based care pathway for women with a breech presenting fetus and a skills development framework for clinicians.

KEY CONCLUSIONS

A cultural shift is beginning to occur through the provision of physiological breech workshops offered by various organisations and may result in greater access to skilled and experienced clinicians for women desiring a vaginal breech birth, ultimately improving the safety of breech birth.

IMPLICATIONS FOR PRACTICES

The care pathway and skills development framework can be used by services wishing to make changes to their current practices related to breech presentation and increase the level of skill in their workforce.

Do specific maternal sensations experienced in late pregnancy correlate to a breech presenting baby? Evaluation of a simple maternal questionnaire

OBJECTIVES

To investigate the effectiveness of a structured questionnaire completed at 36 weeks gestation in predicting breech presentation.

DESIGN

Questionnaire-based study.

SETTING

Tertiary NHS Foundation Trust.

PARTICIPANTS

Women attending for a universally offered 36-week fetal growth scan.

INTERVENTION

Completion of a previously designed maternal questionnaire detailing sensation of fetal movements during the past week, immediately before a routine growth scan.

RESULTS

Between September 01, 2018 and September 30, 2019, 2341 questionnaires were handed out and 2053 were returned. Analysis was performed in 1938 (94.4%) completed questionnaires. Recorded presentation was breech in 109 (5.6%), transverse/oblique in 15 (0.8%), and cephalic in 1814 (93.6%). Women "thinking their baby was breech" had a high positive likelihood ratio, at 11.8 (95% CI 7.4-19.1), but poor sensitivity (27.3%). "Feeling kicks low down or near the bladder" was sensitive for non-cephalic presentation (76.3%) but with poor specificity (48.9%). The questions "kicks low" ("no") (P = 0.013, aOR 2.18 [1.18-4.04]) and 'thinks cephalic ("no")' (P = 0.001, aOR 0.12 (0.04-0.43) were independent risk factors for a non-cephalic presentation.

CONCLUSIONS

The questions posed in this questionnaire could aid the detection of breech presentation, but do not perform better than published data on palpation. Missing a breech presentation near term through palpation alone is well reported. Combining the concept of palpation to exclude breech presentation and these questions may help focus a clinician and improve both palpation skills and breech detection. As a minimum, a woman who believes her baby is breech should be taken seriously.

Impact of point-of-care ultrasound and routine third trimester ultrasound on undiagnosed breech presentation and perinatal outcomes: An observational multicentre cohort study

BACKGROUND

Accurate knowledge of fetal presentation at term is vital for optimal antenatal and intrapartum care. The primary objective was to compare the impact of routine third trimester ultrasound or point-of-care ultrasound (POCUS) with standard antenatal care, on the incidence of overall and proportion of all term breech presentations that were undiagnosed at term, and on the related adverse perinatal outcomes.

METHODS AND FINDINGS

This was a retrospective multicentre cohort study where we included data from St. George's (SGH) and Norfolk and Norwich University Hospitals (NNUH). Pregnancies were grouped according to whether they received routine third trimester scan (SGH) or POCUS (NNUH). Women with multiple pregnancy, preterm birth prior to 37 weeks, congenital abnormality, and those undergoing planned cesarean section for breech presentation were excluded. Undiagnosed breech presentation was defined as follows: (a) women presenting in labour or with ruptured membranes at term subsequently discovered to have a breech presentation; and (b) women attending for induction of labour at term found to have a breech presentation before induction. The primary outcome was the proportion of all term breech presentations that were undiagnosed. The secondary outcomes included mode of birth, gestational age at birth, birth weight, incidence of emergency cesarean section, and the following neonatal adverse outcomes: Apgar score <7 at 5 minutes, unexpected neonatal unit (NNU) admission, hypoxic ischemic encephalopathy (HIE), and perinatal mortality (including stillbirths and early neonatal deaths). We employed a Bayesian approach using informative priors from a previous similar study; updating their estimates (prior) with our own data (likelihood). The association of undiagnosed breech presentation at birth with adverse perinatal outcomes was analyzed with Bayesian log-binomial regression models. All analyses were conducted using R for Statistical Software (v.4.2.0). Before and after the implementation of routine third trimester scan or POCUS, there were 16,777 and 7,351 births in SGH and 5,119 and 4,575 in NNUH, respectively. The rate of breech presentation in labour was consistent across all groups (3% to 4%). In the SGH cohort, the percentage of all term breech presentations that were undiagnosed was 14.2% (82/578) before (years 2016 to 2020) and 2.8% (7/251) after (year 2020 to 2021) the implementation of universal screening (p < 0.001). Similarly, in the NNUH cohort, the percentage of all term breech presentations that were undiagnosed was 16.2% (27/167) before (year 2015) and 3.5% (5/142) after (year 2020 to 2021) the implementation of universal POCUS screening (p < 0.001). Bayesian regression analysis with informative priors showed that the rate of undiagnosed breech was 71% lower after the implementation of universal ultrasound (RR, 0.29; 95% CrI 0.20, 0.38) with a posterior probability greater than 99.9%. Among the pregnancies with breech presentation, there was also a very high probability (>99.9%) of reduced rate of low Apgar score (<7) at 5 minutes by 77% (RR, 0.23; 95% CrI 0.14, 0.38). There was moderate to high probability (posterior probability: 89.5% and 85.1%, respectively) of a reduction of HIE (RR, 0.32; 95% CrI 0.0.05, 1.77) and extended perinatal mortality rates (RR, 0.21; 95% CrI 0.01, 3.00). Using informative priors, the proportion of all term breech presentations that were undiagnosed was 69% lower after the initiation of universal POCUS (RR, 0.31; 95% CrI 0.21, 0.45) with a posterior probability greater of 99.9%. There was also a very high probability (99.5%) of a reduced rate of low Apgar score (<7) at 5 minutes by 40% (RR, 0.60; 95% CrI 0.39, 0.88). We do not have reliable data on number of facility-based ultrasound scans via the standard antenatal referral pathway or external cephalic versions (ECVs) performed during the study period.

CONCLUSIONS

In our study, we observed that both a policy of routine facility-based third trimester ultrasound or POCUS are associated with a reduction in the proportion of term breech presentations that were undiagnosed, with an improvement in neonatal outcomes. The findings from our study support the policy of third trimester ultrasound scan for fetal presentation. Future studies should focus on exploring the cost-effectiveness of POCUS for fetal presentation.

The impact of a universal late third-trimester scan for fetal growth restriction on perinatal outcomes in term singleton births: A prospective cohort study

OBJECTIVE

To investigate perinatal mortality, morbidity and obstetric intervention following the introduction of a universal late third-trimester ultrasound scan for growth restriction.

DESIGN

Prospective cohort study.

SETTING

Oxfordshire (OUH), UK.

POPULATION

Women with a non-anomalous singleton pregnancy undergoing pregnancy care and term delivery at OUH with an estimated due date (EDD) of birth between 1 January 2014 and 30 September 2019.

METHODS

Universal ultrasound for fetal growth restriction between 35⁺⁰ and 36⁺⁶ weeks was introduced in 2016. The outcomes of the next 18 631 eligible term pregnancies were compared, adjusting for covariates and time, with the previous 18 636 who had clinically indicated ultrasounds only. 'Screen-positives' for growth restriction were managed according to a pre-determined protocol which included non-intervention for some small-for-gestational-age babies.

MAIN OUTCOME MEASURES

Extended perinatal mortality, a composite of mortality or encephalopathy Grade II-III, and expedited birth. Other outcomes included composite adverse outcomes used elsewhere, detection of low birthweight and birth from 37⁺⁰ to 38⁺⁶ weeks.

RESULTS

Extended perinatal deaths decreased 27% and severe morbidity decreased 33% but neither change was statistically significant (adjusted odd ratio [aOR] 0.53, 95% confidence interval [C1] 00.18-1.56 and aOR 0.71, 95% CI 0.31-1.63). Expedited births changed from 35.2% to 37.7% (aOR 0.99, 95% CI 0.92-1.06). Birthweight (<10th centile) detection using fetal biometry alone was 31.4% and rose to 40.5% if all abnormal scan parameters were used.

CONCLUSION

Improvements in mortality and severe morbidity subsequent to introducing a universal ultrasound for growth restriction are encouraging but remain unclear. Little change in intervention is possible. The antenatal detection of low birthweight remains poor but improves where markers of growth restriction are used.

Optimal time intervals for vaginal breech births: a case-control study

Background

Breech births are associated with a high rate of hypoxic injury, in part due to cord occlusion during emergence. Maximum time intervals and guidelines oriented toward earlier intervention have been proposed in a Physiological Breech Birth Algorithm. We wished to further test and refine the Algorithm for use in a clinical trial.

Methods

We conducted a retrospective case-control study in a London teaching hospital, including 15 cases and 30 controls, during the period of April 2012 to April 2020. Our sample size was powered to test the hypothesis that exceeding recommended time limits is associated with neonatal admission or death. Data collected from intrapartum care records was analysed using SPSS v26 statistical software. Variables were intervals between the stages of labour and various stages of emergence (presenting part, buttocks, pelvis, arms, head). The chi-square test and odds ratios were used to determine association between exposure to the variables of interest and composite outcome. Multiple logistic regression was used to test the predictive value of delays defined as non-adherence the Algorithm.

Results

Logistic regression modelling using the Algorithm time frames had an 86.8% accuracy, a sensitivity of 66.7% and a specificity of 92.3% for predicting the primary outcome. Delays between umbilicus and head >3 minutes (OR: 9.508 [95% CI: 1.390-65.046] p=0.022) and from buttocks on the perineum to head >7 minutes (OR: 6.682 [95% CI: 0.940-41.990] p=0.058) showed the most effect. Lengths of time until the first intervention were consistently longer among the cases. Delay in intervention was more common among cases than head or arm entrapment.

Conclusion

Emergence taking longer than the limits recommended in the Physiological Breech Birth algorithm may be predictive of adverse outcomes. Some of this delay is potentially avoidable. Improved recognition of the boundaries of normality in vaginal breech births may help improve outcomes.

Correction: The impact of a routine late third trimester growth scan on the incidence, diagnosis, and management of breech presentation in Oxfordshire, UK: A cohort study

[This corrects the article DOI: 10.1371/journal.pmed.1003503.].