Uptake of external cephalic version for term breech presentation: an Australian population study, 2002–2012

Breech presentation refers to fetuses that lie bottom- or feet- first rather than head-first. External cephalic version (ECV) is an effective manipulative procedure for turning a breech-presenting fetus so that it presents head-first for vaginal delivery [1, 2]. Adverse outcomes associated with ECV are rare [3] and the procedure is cost-effective when compared to a scheduled caesarean section [4].

Australian and international clinical guidelines recommend ECV at or near term (37+ weeks gestation) for all women with uncomplicated breech presentations where there are facilities for an emergency caesarean section [5, 6]. It is unknown how well these recommendations have been translated into practice. Thus the aim of this study was to describe the uptake of ECV in the Australian healthcare setting and the maternal and pregnancy characteristics associated with ECV uptake.

Of 32,321 singleton breech pregnancies, 10.5% had a record of ECV at or near term, 22.3% were considered ineligible for ECV, and the remaining 67.2% were potentially eligible for but did not undergo ECV (Fig. 1). Of those considered ineligible for ECV, the most common reason appeared to be previous caesarean section (73.1%), followed by antepartum haemorrhage or abruption (9.0%), oligohydramnios (8.0%), placenta praevia (6.7%), major infant anomaly (6.5%), pelvic abnormality (4.9%), and placenta accreta (1.7%).

Table 1 compares the characteristics of women who had ECV to those women potentially eligible for but without ECV, as well as women ineligible for ECV. Nearly half of the women who underwent ECV were had previously given birth (46.2%) compared to only a third of those without a record of ECV (32.5%). Women who had ECV were significantly older and more likely to be overseas-born than women without ECV. Women with ECV had lower rates of smoking, morbid obesity, and hypertensive disorders than women who were eligible but did not have ECV. The two groups did not differ on the rate of diabetes.

ECV was strongly associated with hospital and patient type: 77.7% of women with ECV delivered in a public hospital as a public patient compared to 64.0% of those without ECV; and 45.8% of women who had ECV delivered at an urban tertiary hospital whereas only 25.1% of those without ECV did so.

During the 11-year study period, only 10.5% of women with breech presentation at or near term underwent ECV in NSW, with potentially 6 times more women eligible for ECV who did not undergo the procedure.

To our knowledge, this is the first population-based study of ECV uptake in Australia and it shows there is considerable room for improvement in the uptake of ECV. Despite local guidelines suggesting ECV for in all women with uncomplicated breech presentations, these recommendations do not appear to have translated well into clinical practice in the state of New South Wales, Australia’s most populous state.

While ECV has become more common across Australia in the last decade, based on the absolute number of procedures billed to the federally funded healthcare system [18], the uptake of ECV services relative to the number of eligible women with term breech pregnancies is low. Our estimate for the uptake of ECV was 10.5% for all women with breech presentation at or near term, or 13.5% of women considered eligible for ECV. Previous Australian studies have found ECV attempted in 39% of women with breech presentation between 36 and 38 weeks in one hospital [19] and 71% of eligible women in another [20]. The higher rates of uptake in previous studies are unsurprising given that they were conducted in tertiary centres with specialist breech services. This suggests that the provision of specialist breech clinics may facilitate the uptake of ECVs as an effective and low-cost procedure.

Contributors to the low rate of ECV uptake include selection of women for ECV based on criteria other than those stipulated in clinical guidelines and undiagnosed breech presentation. We found a lower rate of morbid obesity and hypertensive disorders in women who had ECV compared to those potentially eligible for ECV suggesting that clinicians are selectively offering ECV to low-risk women, counter to current guidelines for best practice. Previous caesarean section was the most common reason women were deemed ineligible for ECV with only 2.6% of women with ECV having a history of caesarean section compared to 16.6% in women with breech presentation overall. There may be a clinical perception that with a previous caesarean section there are no safe options, however, there is little evidence that caesarean section should be considered an absolute contraindication for ECV [21]. To the contrary, there is some evidence suggesting the success and associated risks of ECV in women with one previous caesarean section are similar to those in women without such history [22, 23]. Similarly, selection on factors favourable to ECV may have occurred: multiparous women were more likely to undergo ECV even though nulliparous women comprise the majority of women with breech presentation. This may also reflect different likelihoods of accepting ECV among nulliparous and multiparous women, especially if women are counselled that success rates are higher in multiparae. This is concerning given the high risk of recurrence for breech presentation [24]; a lower rate of ECV uptake in nulliparous women has implications for not only the first, but also subsequent pregnancies.

Other potential barriers to ECV uptake may include ECV not being offered by clinicians or being declined by women, but the role of these factors are unclear since no population data are collected at these crucial time points. The uptake of ECV was strongly associated with the type of hospital attended by women and public/private patient status suggesting clinicians and women in private and regional hospitals need to be the targets of any intervention to promote ECV uptake.

A study in a large British maternity unit has found that ECV counselling, referral, and attempt rates have increased over recent years, and that intrapartum diagnosis of breech presentation remained the largest barrier to ECV uptake [25]. We suspect that trends in Australia are similar and that intrapartum diagnosis of breech presentation remains a considerable barrier to ECV uptake. We do not know how many undiagnosed breech presentations were included in the current study, but a previous study in an Australian tertiary hospital suggests intrapartum diagnosis occurred in almost 20% of cases [20]. Importantly however, even if this rate of intrapartum diagnosis held true for our study population, a further 40% of breech pregnancies remain eligible for ECV.

The success of ECV in the current study was 37% for nulliparous and 63% for multiparous women and these rates are consistent with those previously reported in Australian hospitals [19, 20, 26, 27]. The overall success rate of 49% was lower than the 60% success rate reported in reviews of the literature [1, 2], but probably reflects lower success in the general population of pregnant women compared to selected trial participants or in specialist clinics with more experienced providers. The relative reduction in caesarean section was similar: a quarter of women with successful ECV delivered via caesarean section compared to 21% in other studies [2].

We found that neonatal outcomes were similar regardless of ECV success, thus providing a stronger incentive for attempting ECV in conjunction with existing evidence in the Australian setting [19, 20, 26, 27], and world-wide, that the complications of ECV are rare and unrelated to the success of ECV [3]. The small risks of serious complications (<0.4%) leading to emergency caesarean section [3] must be weighed against the substantial potential benefits of a successful ECV and the advantages of avoiding a caesarean section or vaginal breech delivery.

Currently the majority of women with breech presentation in NSW do not undergo ECV, although greater uptake of ECV would reduce breech presentation, diminish the associated risks and costs of caesarean section and bypass those associated with vaginal breech birth. Improved monitoring of ECV attempts, success, and outcomes will aid in identifying barriers to ECV uptake, while specialised breech services, especially those targeted to women birthing in regional areas and private hospitals, and further training or capacity building among clinicians may facilitate greater use of ECV.