Breech Birth After Caesarean (BBAC)

Another post responding to maternity service user demand for better information and more individualised care for breech presentation, prompted by a discussion on the Coalition for Breech Birth Facebook group.

In these days of growing awareness of the risks associated with doing too many caesarean sections, women planning an elective section for breech presentation are informed that they can and should be encouraged to try for a vaginal birth after caesarean section (VBAC, or just BAC). Yet how many are informed that she has a 1:10 chance of the breech presentation recurring in the next pregnancy (Coughlan et al 2002, Ford et al 2010)? And that if her second baby is breech there is almost a 1:3 chance that her third will be? That this likelihood is increased if she, her mother or her father were breech (Nordtveit et al 2008)?

‘Breech’ remains an issue for many women throughout their reproductive lives, so much so that some have argued it is ‘physiologically normal’ for some women (Albrechtsen et al 1998). And many women will have spent time between pregnancies considering the information which led them to choose an elective section, and arriving at a very different point of view by the end of their second pregnancy.

The Royal College of Obstetricians and Gynaecologists’ guideline lists a ‘scarred uterus’ (which would include post-CS, as well as other uterine surgery, such as myomectomy) as a contraindication to a vaginal breech birth (VBB). However the guideline also refers to one (small) study which specifically looked at success rates for BBACs:  Ophir et al 1989 had really good outcomes, and a higher rate of successful vaginal birth than many series report. But bigger numbers would be more reassuring, and they need to be compared to results for other VBACs.

(Incidentally, a previous CS is often considered a contraindication for ECV as well, but I found no studies demonstrating an increase in uterine rupture. Burgos et al 2014 looked at this and reported no uterine ruptures in 70 ECVs. Higher numbers would be more reassuring, but this is the problem with breech research – higher numbers are tricky to come by!)

The PREMODA study reported two adverse outcomes for BBACs, which accounted for 2/3 of the deaths they concluded could have been prevented had elective sections been performed at 39 weeks. One woman arrived to the hospital with contractions, but no fetal heart tones. The other woman experienced a spontaneous uterine rupture at 40 weeks, when a VBB was planned. Both complications associated with a pregnancy following a CS in general, not BBAC labours.  Oh, how unfortunate it must have felt – for the families and for the researchers – to have their beautiful breech outcome stats affected by the CSs they were trying to prevent! Understandably, given the current climate which blames any adverse outcome on the breech, they recommended BBACs be avoided.

We talk a lot about risks of labour, but increasing evidence points to risks of not labouring as well. Two obstetricians, Sinha and Bewley (2010) point out in their article, ‘Myth: babies would choose prelabour caesarean section:’

Babies who do not experience labour have significantly increased respiratory and other morbidities that may have profound effects on development, determining immediate and potentially life-long disease. It is thus surprising that obstetricians do not advocate awaiting or inducing labour even in women considering CS. (from the abstract)

Ulander et al al 2004, a Finnish team, draw similar conclusions in their comparison of breech, vertex and caesarean deliveries, ‘Are health expectations of term breech infants unrealistically high?:’

As regards the long-term outcome of the children, the only statistically significant difference was in the number of visits to out-patient departments which were less frequent for breech infants born vaginally than breech infants born through CS (OR 0.70, CI 0.53–0.93) or vertex infants born vaginally (OR 0.58, CI 0.47–0.72) (Table III). The cumulative incidence of long- term morbidity was lower in breech infants born vaginally than in breech infants born by planned CS (OR 0.47, CI 0.28–0.80). (p 83)

Any future research on breech or VBAC should include these long-term outcomes as well. Ulander et al found that the risks of birth trauma were smaller for breech-born babies than for cephalic-born babies, but smallest over all for CS-born babies. Undoubtedly, labour introduces some risks — especially first labours, VBAC labours, breech labours. But like many things in life, sometimes taking those risks results in long-term benefits, which can only be perceived further along down the road. A BBAC is a reasonable choice, which should be supported.

What additional precautions might be in order? A dysfunctional labour is a risk factor for both VBAC and breech labour. Especially if the birth will occur in a unit that does not routinely recommend and promote vaginal breech birth, and thus will not be saturated with experience, inducing or augmenting a BBAC is asking for trouble.

Shawn

Further Research:

  • Bourtembourg, A., Mangin, M., Ramanah, R., Maillet, R., et al. (2013) [Breech delivery and scarred uterus: A special obstetrical situation?]. J Gynecol Obstet Biol Reprod (Paris). 42 (4), 351–358. Conclusion: Vaginal breech delivery in case of a scarred uterus is possible, if each obstetrical situation is correctly studied to authorize a vaginal birth trial after a careful selection of patients and a strict management of labour. Vaginal birth does not seem to increase maternal and neonatal morbidity and mortality in this situation.

What are your thoughts?