Women with breech presentation at term should now be offered the choice of a vaginal or caesarean birth, benefits and risks of both for her individually, and the implications for future pregnancies (RCOG, 2017). Vaginal breech birth and vaginal twin birth are both made safer by the attendance of specialist, skilled practitioners (Su et al, 2003; Barrett et al, 2013). When it comes to the combination of vaginal breech and twin births, there remains a lack of professional consensus on the safety of vaginal birth compared to planned caesarean. This is particularly true of breech presenting twins, where the first twin is breech at term, compared to twins in a vertex-breech order, which has been subject to more research.
RCOG breech guidance (2017) recommends planned caesarean in cases where the first twin is breech, but not in the case of twins where the second twin is breech. This recommendation is influenced by the Hogle et al paper (2003), which found lower Apgar scores at five minutes for breech-first twins born vaginally. However, the paper did not find any other significant negative outcomes for these babies, such as neonatal unit admissions, need for resuscitation or increased mortality. Women considering a vaginal breech birth are now routinely informed that following a vaginal breech birth, babies are more likely to have lower Apgar scores, but that this does not translate into severe illness or long-term health consequences. Therefore, breech lead twins behave similarly to singleton breech babies who are born vaginally, meaning they should also be suitable for vaginal birth depending on maternal choice.
As with many areas of breech, research studies are mostly retrospective and often reporting on small numbers. Nonetheless, evidence dating from 1998-2022 suggests no significant difference in neonatal morbidity or mortality for lead breech twins born vaginally or by caesarean, or any difference in outcomes for breech lead twins compared to cephalic lead twins (Grisaru et al, 2000). In 2020, Korb et al published their secondary analysis of the JUMODA twin study, which concluded that planned vaginal birth with a breech twin first is not associated with higher neonatal mortality or morbidity for either twin. In their systematic review, Steins Bisschop et al (2012) found no difference in neonatal outcomes between vaginal or caesarean birth for breech first or second twin. Several authors stress the value of practitioners and centres having exposure to and skills in facilitating vaginal breech and vaginal twin birth.
Where caesarean is recommended (Nassar et al, 2005; Hogle et al, 2003), these papers appear to generalize the singleton findings of the Term Breach Trial (Hannah et al, 2000), which have since been called into question. Bourtembourg et al (2012) recommend caesarean for nulliparous clients, but this is based on likelihood of vaginal birth, rather than negative impact on mother or baby. The RCOG breech guideline (2017) mentions the risk of interlocking when the first twin is breech, but the only available evidence on this is from Cohen et al in 1965; none of the studies analysed in this review cited interlocking of twins to be a significant labour complication.
The impact on maternal health was not included in many of these studies, but where this was considered, findings suggest either no difference to maternal morbidity (Bats et al, 2006); a greater incidence of postpartum haemorrhage following planned caesarean (Ghesquière, 2022); or an increased incidence of deep vein thrombosis and pulmonary embolism (Sentilhes, 2007) following planned caesarean. These findings should be incorporated into consultations on the benefits and risks of modes of birth.
According to the evidence reviewed, planning a vaginal birth with breech-presenting twins is a reasonable choice and should be approached in a similar way to singleton breech birth. However, the birth must be facilitated in a unit with staff skilled and experienced in vaginal breech and vaginal twin birth.
Are there any additional considerations?
Estimated fetal weight should be considered. Blickstein et al (2000) found benefits from planned caesarean in cases when the breech twin weighed less than 1500g. As is often the case in breech, babies weighing over 3800g were recommended for caesarean section in many studies, which means they are omitted from the current evidence base.
Jacana Bresson
This post was originally written as a Letter to the Editor, but when I went to submit it, I discovered the on-line journal does not accept any unsolicited writing. All of the articles are ‘commissioned by the Editors from specialists in their field,’ so I guess we should read them as more of a pronouncement than the opening of a dialogue?