From the 4th World Congress on Controversies in Obstetrics, Gynaecology and Infertility  

The term breech: is it still a controversy?

Mary Hannah, MD interviewed by Hans van der Slikke, MD, PhD

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Hans van der Slikke, MD, PhD: “It’s April 2003, we are in Berlin at the Controversies in Obstetrics and Gynaecology conference and I am very proud that Mary Hannah from Toronto, Canada, sits next to me. Welcome Mary.”

Mary Hannah, MD: “Thank you.”

Hans van der Slikke, MD, PhD: “One of the controversies in this conference was the term breech and I wonder why, after your, I may say, legendary paper about two and half years ago it still seems to be a controversy, why is this?”

Mary Hannah, MD: “Well, I think it’s not a controversy in many obstetricians' minds. They’ve moved on to a policy for caesarean section in many places, but there are still some centres and some obstetricians who are reluctant to let vaginal breech delivery go, apparently because they feel very comfortable with that delivery. They feel that it’s safe in their hands. They are reluctant to lose it, they are worried about the risks of caesarean sections for women, particularly long-term, and I suspect they’re maybe not completely convinced by the findings of the Term Breech Trial but I would say that’s a small minority. Most obstetricians have welcomed the findings of the Term Breech Trial, have found them convincing for them and for their practices, and have been using the results in their settings.”

Hans van der Slikke, MD, PhD: “That’s true but there still seems to be a kind of an emotional problem still.”

Mary Hannah, MD: “Yes, as you say, well the Term Breech Trial evaluated a procedure, which is undertaken by people and so we tested it and it failed – it came out faulty. And I think perhaps some obstetricians feel that their own skills and experience have been tested and found to be faulty and particularly for those who weren’t actually in the Term Breech Trial and even for some that were in the Term Breech Trial, they are reacting to that. I think it’s perhaps natural.”

Hans van der Slikke, MD, PhD: “You mean the natural kind of grief that they are disappointed? That they didn’t do better?”

Mary Hannah, MD: “That’s correct, yes.”

Hans van der Slikke, MD, PhD: “So some of the questions were maybe if you do sub-group analyses some other factors will appear and today you presented a part of your sub-group analysis and were there any factors that were important to the sub-groups?”

Mary Hannah, MD: “We did extensive sub-group analyses. Our collaborators participating in the trial asked us, encouraged us, to do many sub-group analyses to see if there was one or some sub-groups where vaginal breech delivery still had a role, where planned caesarean wasn’t found to be better. 

We did find one sub-group where it appeared that planned caesarean section wasn’t that much better than planned vaginal birth. That was in a sub-group defined by the type of country. That is to say countries that had high, national perinatal mortality rates, such as one might see in the developing world, in those settings, planned caesarean section didn’t improve the results nearly as much as in the more developed world. 

But all the other variables that we looked at: maternal age, parity, the size of the baby, the way the pregnancy was assessed, etc. didn’t change the findings. In other words: planned caesarean was better than planned vaginal birth irrespective of whether women were older or younger, irrespective of whether it was the first baby or if women had had a baby vaginally before, etc. 

It was just very conclusive that regardless of the population we looked at, planned caesarean came out better, except as I say for the type of country where it did make a difference.”

Hans van der Slikke, MD, PhD: “The difference if you express this is in the numbers to treat, then you had this striking difference in the number of caesareans you had to do to save one baby?”

Mary Hannah, MD: “Yes. We looked at the number needed to treat a little bit differently than it’s usually done because caesarean section was part of both policies. We looked at the number of additional caesareans that would be needed to be done and we found that in low PMR countries, such as the Netherlands or Canada or the USA, etc., that the number of additional caesareans was seven, not very many; whereas in high PMR countries, the number of additional caesareans that would be needed to prevent one baby with a problem was 39. So it didn’t appear that a policy of planned caesarean would have the same benefit to babies in those settings.”

Hans van der Slikke, MD, PhD: “So it’s very convincing, especially for low PMR countries. One of the comments today was that you have rather many primips in your study, 53%, which is much higher than average. How do you explain this difference?”

Mary Hannah, MD: “It’s only higher than average in some settings. Women joined the study from many different countries and in some countries there’s a higher percentage of primips than multips but having said that, there are selection issues, in joining a randomised control trial and doctors have their own criteria for when they will feel comfortable recommending enrolment into a trial, to a woman. And women also have their own criteria for whether they want to join a study and they vary by setting. 

So in some centres obstetricians were very comfortable delivering multips vaginally and so they wouldn’t enrol multiparous women because they wouldn’t want to do a multip caesarean section. So they would only enrol primiparous women. Whereas in other setting obstetricians were very uncomfortable delivering primips vaginally so they wouldn’t enrol those women they would only enrol multips. So that varied by comfort level and by setting. But I guess the question is: do the findings reflect primips and do the findings reflect multips?”

Hans van der Slikke, MD, PhD: “Yes, in a sub-group analysis you showed that there was no difference in the two groups.”

Mary Hannah, MD: “That’s correct. The planned caesarean reduced the risk of the primary outcome versus planned vaginal birth in multips similarly to primips.”

Hans van der Slikke, MD, PhD: “One of the points always raised in this discussion is what about training? If you lose your skills it will be even worse because there will always be some emergency breeches which it is too late to deliver them…can you …?”

Mary Hannah, MD: “What can we do about that? I think training is an important issue. We need to think of creative ways of doing a better job of training and maintaining skills in vaginal breech delivery. Not just for those pregnancies where women present too late for a caesarean section but also for women who, based on the evidence, would prefer a vaginal birth. So we need to work very hard on that. But I don’t think an approach to use is to impose a policy of planned vaginal birth for women just so that physicians can maintain their training.”

Hans van der Slikke, MD, PhD: “No, no, that’s correct. The last point I want to address is the late complications. You know that after a caesarean section the next delivery can be a problem because of that previous caesarean section. Of course you did not yet include this but do you intend, maybe five years later, to see how many women became pregnant after this index pregnancy?”

Mary Hannah, MD: “The Term Breech Trial has included in it a two-year follow up of mothers and babies and that should be submitted for publication sometime this year. We are, in that follow up, looking at subsequent fertility, pregnancy, recurrent caesarean sections as well as incontinence, relationships with the child and with the partner, etc., post-partum depression, a number of outcomes. We’re looking at two years, but we’re not going to be able to follow mothers in the study longer than that and so we won’t be able to comment on what happens at five years, ten years, etc. So I think there will still be some uncertainties as to the risks longer term. 

But I think it’s not just a question of whether women deliver vaginally or whether they are delivered by caesarean, because with the policy of planned vaginal birth, where women attempt to deliver vaginally, somewhere around half will end up with a caesarean section, usually done after a period of labour, perhaps after a period of ruptured membranes. And there are some data that suggest that when women have a caesarean in those circumstances their outcomes are worse than if they have a caesarean electively, planned at 9:00 in the morning, they come in rested, etc. I think when we do long-term outcome studies of caesarean we need to be able to differentiate the outcomes of women delivering electively versus those delivering by caesarean during labour.”

Hans van der Slikke, MD, PhD: “Maybe this means that the only way to prevent caesarean section for this is to try external version and then you also presented a poster at this conference, from your group. Where you proposed a version trial early versus late version.”

Mary Hannah, MD: “Yes.”

Hans van der Slikke, MD, PhD: “When will this start?”

Mary Hannah, MD: “That trial has been submitted for funding to the Canadian Institutes of Health Research and we should hear in the fall of this year. Actually a pilot trial of that study was undertaken by Eileen Hutton, who is the lead investigator on the proposed study as well. She did a small study of comparing external cephalic version slightly before term versus at term and the findings were quite promising, suggesting that if we undertake external cephalic version a bit before term we may have a higher success rate. But the study was too small to be definitive and also we didn’t have enough women in the study to be able to comment on outcomes for the babies.”

Hans van der Slikke, MD, PhD: “Which is maybe a little different than the Cochrane says now? It says now that it is a little bit better to wait until after 36 weeks.”

Mary Hannah, MD: “Yes, the external cephalic version trials at term show quite clearly that ECV at term will reduce the need for caesarean section compared to no ECV. At least in many settings ECV at term is the standard of care. 

The problem with ECV at term is that in many settings it’s unsuccessful with success rates often less than 50% depending on the woman. So the question is how could we improve success rates? The thought behind the early ECV-2 trial is that ECV at 34 weeks, not very pre-term but just in the few weeks before term might make the difference. 

The randomised control trials in the Cochrane review of early ECV are not methologically strong. A number of them are not truly randomised trials and a number of them recruit women as early as 28 weeks when the babies are still flipping around. So the question about near term but prior to term hasn’t really been well addressed.”

Hans van der Slikke, MD, PhD: “How big will the trial be?”

Mary Hannah, MD: “The trial is planned to be about 1500 women and the primary outcome for the trial will be the caesarean section rate to see if performing ECV a little bit before term can reduce the need for caesarean among women. But the secondary outcome is the rate of preterm birth. So we anticipate the trial will be large enough to provide some comfort that performing ECV earlier doesn’t cause the babies a problem. 

That study hopefully will be funded in the fall, we’ll be able to begin that early in 2004 and as with our previous trials they’ll be multi-centre and international, and we’ll be inviting those in centres to join who are experienced at external cephalic version and find the question an important one in their settings.”

Hans van der Slikke, MD, PhD: “So, we’ll publish the link to this trial on our website as well.” http://128.250.188.72/psanz/Hobart%202003/15-Posters-P97-119.doc.

Mary Hannah, MD: “That would be just great – thank you.“

Hans van der Slikke, MD, PhD: “I thank you really very much for your participation in this interview.”

Mary Hannah, MD: “Thank you.”