Helping the aftercoming head to flex in upright breech births

When women are in upright positions, many breech births will proceed completely spontaneously because the birth canal follows the flow of gravity. However, the attending clinician may need to assist, either because maternal effort no longer results in steady progress, or because the baby appears compromised and assistance will result in a quicker delivery.  In this blog, I describe one manoeuvre to help in upright breech births.

The shoulder press is very effective in the following circumstances:

• The aftercoming head has descended through the pelvic inlet and is either on the perineum (chin visible) or mid-pelvis (chin not visible, but easily reached in the sacral space); and the occiput is anterior
• The mother is in an upright, forward-leaning position (e.g. all fours or kneeling)
• The clinician facilitating the birth is behind the mother, and the baby is directly facing the clinician (‘tum to bum’ with mother), with head and body in alignment

In this scenario, the maternal pubic arch is directly behind the baby’s occiput. When pressure is applied to the baby’s torso along the clavicular ridge, guiding the baby’s body straight back through the mother’s legs, the pubic arch will push the occiput up and forward. This causes the aftercoming head to flex and descend, following the curve of the birth canal. The sternocleidomastoid muscles (SCM), responsible for head flexion, attach to the superior aspect of the clavicle and keep the head in alignment throughout this process.

Buttock/Gluteal Lift – If descents stops with the perineum tight on the baby’s forehead (bregma), and the shoulder press alone has no further effect, an assistant can augment the manoeuvre by lifting the woman’s buttocks up and out. This lifts the perineum over the bregma as the primary attendant performs the shoulder press, moving the baby in the opposite direction. This assisted manoeuvre is especially helpful when the woman is obese, or the perineum is especially tight and intact.

The feeling and effectiveness of this manoeuvre is very easy to replicate using an obstetric model, turned upside down, as in the video below.

Potential benefits

Preserving an intact perineum. An intact perineum helps to maintain beneficial fetal flexion, and routine episiotomy should be avoided for this reason. However, when the aftercoming head has descended onto the perineum, reaching the maxillary or malar bones to perform a modified Mariceau-Smellie-Veit (MSV) can be difficult. Therefore, many clinicians will cut an episiotomy early in order to avoid cutting one while the baby’s face is on the perineum. However, this is not necessary. When the chin is visible, pressure on the maxillary bones through an intact perineum is possible, in combination with upward pressure on the occiput behind the pubic arch, enabling descent to continue. However, the shoulder press is more effective.

Clinicians who are inexperienced or untrained in manoeuvres specific to upright birth will be tempted to pull down on the baby’s torso to deliver the head. However, this does not follow the direction of the birth canal in the same way as the shoulder press as described. Pulling rather than pushing is potentially more likely to result in severe perineal damage, and may also cause cervical nerve damage in the baby due to increased resistance from the intact perineum.

Potential risks

Fractured clavicle. When applying pressure on the clavicle, fracture is an obvious potential risk, although neither I nor those I have learned from have reported fractured clavicles resulting from the use of this manoeuvre. This potential risk can be minimised by spreading the fingers to apply even pressure along the entire ridge, or by applying pressure with fingers or thumbs at the distal aspect, near the glenohumeral joint. The pressure exerted is firm but is not significantly different to that applied when delivering an anterior shoulder in a supine cephalic delivery, and therefore no more likely to result in trauma. The shoulder press minimises the amount of force needed to achieve delivery by promoting maximum head flexion and descent in the direction of the birth canal.

Limitations

The shoulder press as described, on its own, may not resolve a dystocia caused by a deflexed or hyperextended aftercoming head. A very high chin, pointing upwards, identifies a hyperextended head; only the bottom jawbone (resembling a ‘bird beak’) is felt at the very top of the maternal sacrum. If the deflexed head has impacted at the pelvic inlet, the baby’s whole body may need to be lifted in order to flex and/or rotate the head to oblique so that it can enter the pelvis before the shoulder press is useful. Additionally, suprapubic pressure performed by an assistant may help flex the head enough to pass through the pelvic inlet.

Uses

The practice of supporting breech births with the mother in an upright position is somewhat controversial, as minimal research evidence regarding effectiveness exists. Although breech experience is generally at a very low level, most clinicians are only trained to perform lithotomy manoeuvres, and therefore the RCOG recommend lithotomy as the preferred maternal position (RCOG 2006). However, increasingly women are requesting freedom of movement and their own preference to be upright, which is potentially a more satisfying birthing position (Thies-Lagergren L et al 2013). In the absence of evidence that such an approach increases risks, introducing upright manoeuvres into mandatory training will enable this option.

In addition, through discussions with other midwives and participation in the risk management process for various Trusts, I have been informed of several cases of undiagnosed breech births where women were instructed to get onto their backs on their floor following the diagnosis of a breech in labour, due to lack of an obstetric bed in that setting. In some cases, this has been associated with severe delay in delivering the aftercoming head. In true lithotomy, head flexion is promoted by allowing the baby to hang off the end of the bed, where the maternal pubic arch again is responsible for lifting the occiput as gravity gently pulls the baby through the birth canal. This cannot occur on the floor, and the head becomes deflexed. In these cases, the midwives were only trained to perform lithotomy manoeuvres, and instructed that guidelines required them to manage breech births in this way, but the births occurred in settings with no obstetric bed. Providing mandatory training in upright breech to those working in midwifery-led settings will potentially improve outcomes in emergency cases in the short term, and increase maternal choice in the long term.

Sources

I first learned about this mechanism from Dr Anke Reitter, FRCOG, of Frankfurt, Germany, and Jane Evans, an experienced UK Independent Midwife. At the University Hospital Frankfurt a similar technique is called ‘Frank’s Nudge’ after the lead obstetrician, Prof Frank Louwen, who introduced the upright management of breech birth to their unit. I do not refer to the manoeuvre as ‘Frank’s Nudge’ because research indicates eponyms cause confusion and lead to inaccurate documentation. Some have described the mechanism as a reflex action, but my hands have experienced it as purely mechanical, and much more effective than Mariceau-Smellie-Veit when women are upright. Others have described a similar experience in my qualitative studies of how people learn vaginal breech birth skills.

References

RCOG (2006) The Management of Breech Presentation. RCOG Green-top Guidelines, No. 20b. London, Royal College of Obstetricians and Gynaecologists.

Thies-Lagergren L et al (2013) Who decides the position for birth? A follow-up study of a randomised controlled trial.” Women and Birth 26(4): e99-e104.