A few reasons to be cautious about the idea of routinely scanning for breech presentation near term

This week saw the publication of a study claiming that “universal late pregnancy ultrasound in nulliparous women (1) would virtually eliminate undiagnosed breech presentation, (2) would be expected to reduce foetal mortality in breech presentation, and (3) would be cost effective if foetal presentation could be assessed for less than £19.80 per woman.” (Wastlund et al 2019).

In, ‘Screening for breech presentation using universal late-pregnancy ultrasonography: A prospective cohort study and cost effectiveness analysis’, Wastlund et al (2019) “sought to determine the cost effectiveness of universal ultrasound scanning for breech presentation near term (36 weeks of gestational age [wkGA]) in nulliparous women.”

Some people have begun to express concern about the implications of this paper and the fact that it hasn’t considered the fact that breech birth is seen by many as a variation of normal. Neither has it explored the wider picture of women’s decision making. Here are a few of the issues that have not been taken into account within the study and/or in some of the media reporting of the research.

Further increasing the caesarean rate

The claim that routine scanning would ‘prevent 4000 emergency caesareans per year’ has been seen by some as misleading, because if the ‘answer’ to finding a baby in a breech presentation is to offer a caesarean section as one of the options, then the overall number of caesareans may well increase. It may be true that an elective (planned) caesarean is preferable to an emergency caesarean but women also need to know that, if late-pregnancy scanning is offered and they decide to have it, their chance of being offered a caesarean may go up. This is of particular concern given the already rising caesarean section rate, which sits amidst the rise in other interventions but without good evidence of improvements in outcomes. Other interventions that would be offered to women found to have breech-presenting babies, such as external cephalic version, also have potential downsides as well as potential benefits.

It’s not a guarantee

We need to understand that scanning every woman at 36 weeks of pregnancy isn’t a guarantee that all breech births will be prevented. Even though most babies don’t turn after this time, some will, and some babies who are breech at 36 weeks of pregnancy will turn the other way up spontaneously. Just yesterday, a friend of a friend had a caesarean for a baby who had been breech on a scan and who was head-down when the caesarean was done. This isn’t a rare event; it happens more often than you might think. We need to understand that there is no such thing as a guarantee, or a risk-free option.

Is it safe?

Ultrasound remains a relatively unevaluated technology, and campaigners are still calling for research into the safety of ultrasound, especially in response to data that has emerged from Chinese research on this intervention. Scanning is currently in use where a problem is suspected, and will often be offered on an individual basis if there is uncertainty about the baby’s position. In this scenario, the potential benefits are deemed to outweigh the potential risks. It is the suggestion that all babies should be exposed to another scan that is controversial.

What are the wider costs?

Although the study authors spoke about the financial costs of ultrasound scanning, this research did not consider the wider costs to women, which include (but are not limited to) the physical, emotional, social and other costs of this screening. We know that screening leads to anxiety for many women and we also know that all screening will lead to some women being told that they have a problem (and thus being offered intervention) when they do not. It is vital that these costs and the way that this might affect individuals are considered and that decisions aren’t made on the basis of financial considerations alone.

A variation of normal?

The study assumes that vaginal breech birth is a hazardous, unwanted outcome. This is a controversial statement that not everyone would agree with. As above, breech birth is seen by many people as a variation of normal, and many women prefer to have their breech baby vaginally. Routine scanning may put more unwanted pressure on more women. In relation to outcomes, we do know that medically-managed vaginal breech birth seems to lead to poorer outcomes than caesarean section, but those are not the only two options. Breech babies can also be born physiologically, without routine medical intervention or management (unless there is a problem and it is warranted). We are seeing more and more research on how physiological breech birth can be safe, and a recent analysis even shows that “home or birth center setting [which would also involved an approach supportive of a woman’s physiology] leads to high rates of vaginal birth and good maternal outcomes for both breech and cephalic term singleton presentations”. While many people would argue that hospital is the best location for breech birth, there are options for this type of birth that are not being taken into account in this analysis.

These are just a few of the concerns that have been raised about the topics addressed by this paper. I will link to other commentaries as they arise. If you’d like to be kept up-to-date with birth-related research and thinking, jump on my newsletter list.

Wastlund D, Moraitis AA, Dacey A et al (2019). Screening for breech presentation using universal late-pregnancy ultrasonography: A prospective cohort study and cost effectiveness analysis. PLOS Medicine https://doi.org/10.1371/journal.pmed.1002778

5 comments for “A few reasons to be cautious about the idea of routinely scanning for breech presentation near term

  1. Gill boden
    April 18, 2019 at 6:16 am

    As Sara says, ultrasound is a relatively untested technology. Those who use it every day are clear that it should not be used routinely but only where there is a clear medical indication. Women need to be made aware of how little research has been done into any long term effects of ultrasound on developing brains before they can give informed consent to routine screening of this kind.

  2. April 19, 2019 at 12:13 am

    Is palpation (from a known midwife) not an effective way to determine presentation?

  3. ErickaI
    April 21, 2019 at 1:25 am

    i think core health has something to do with this. a strong complete core – especially the transverse – plays a role in babys position too.

    my 4th pregnancy last year my core was SHOT. and my belly was HUGE. i was planning my 2nd homebirth with a midwife. everything was fine, up until week 36 when she flipped transverse! :O this was horrifying for me because there is no natural birth in transverse! BUT, i did some very consistent and serious spinning babies positions and releases, massage, chiropractic from a chiro who knew the webster method, and even craniosacral work! all of it must have helped because she did indeed flip head down within 2 weeks. it was seriously scary, but i was so happy that all the work i did in the end helped her get past the “speedbump” of a tense ligament so she could keep her little head down. when i went into labor, we did robozo to hold my belly up and in to get her more direct pressure on my cervix and my homebirth went wonderfully just like my previous births in just 2 hours roughly. <3

    i think IF these methods get used, women need to hear more than "so when should we plan the c-section" – they need to hear "here is a list of things that you can do naturally and healthy for your body to help!"
    its SO IMPORTANT that women know there is something they can do! and really, these are things they can be doing all along. hubby had gone on seasonal unemployment so i stopped going to the chiro for a couple weeks and thats when she went transverse. i wish i had never stopped, all i had to do was talk to my chiro, she was more than happy to treat me and have me pay her later. <3 i love her so much for that! <3

  4. erickajen
    April 22, 2019 at 7:21 pm

    i wrote a comment – but i still dont see it… did it work?

  5. Anna de Best
    May 10, 2019 at 2:24 pm

    I am not a big fan of standard US at all visits to an Gynaecologist or midwife and even though in our place we are all very skilled in manual palpation, we do have unexpected breeches about 2 twice a year. I am not scared of breeches but we are legally not aloud to have them in our birth centre, And in these cases I think knowing well ahead may even help the woman to negociate for a vaginal birth while being in labour and realizing the breech position makes it more constarining to discuss with the health care providers at the hospital.

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