Balloon disimpaction of the baby's head at emergency caesarean during the second stage of labour

A caesarean during the second stage of labour is associated with an increased risk of adverse perinatal outcomes compared with an elective caesarean or a caesarean during the first stage of labour. Delivery of the baby can be more difficult if the head is impacted deep within the pelvis, further increasing the risks to the woman, trans man or non-binary person giving birth, and to the baby. The definition of impaction of a baby's head is subjective. But a UK survey published in 2023 proposed the definition: 'A cesarean birth where the obstetrician is unable to deliver the fetal head with their usual delivering hand, and additional maneuvres and/or tocolysis are required to disimpact and deliver the fetal head' (Cornthwaite et al. 2023).

Difficulties in disimpacting a deeply engaged baby's head can delay the birth of a baby that is already at risk. For the woman, trans man or non-binary person giving birth, there is an increased risk of complications such as:

• extension of the uterine incision

• haemorrhage

• infection

• bladder injury.
  
  For the baby, complications include:

• umbilical artery acidosis

• skull or limb fracture

• hypoxic ischaemic encephalopathy

• brachial plexus injury.

Two main approaches are commonly used to disimpact an engaged baby's head. One involves the surgeon or an assistant placing fingers of a cupped hand through the vagina and pushing the baby's head back up the pelvis. This can be associated with vaginal tissue trauma. The other approach (reverse breech extraction) involves the surgeon delivering the baby's feet first through the uterine incision, and then delivering the head. The Patwardhan technique and the modified Patwardhan technique are modifications of the reverse breech extraction method. They involve delivering a shoulder or both shoulders of the baby first, followed by the body and, lastly, the head.

Impaction of the baby's head makes a caesarean delivery more difficult and is associated with an increased risk of complications. There is no clear consensus on the safest and most effective technique to support disimpacting the baby's head before or at an emergency caesarean. The situation is also affected by the baby's position. The aim of balloon disimpaction is to elevate the baby's head and make a caesarean delivery during the second stage of labour less traumatic and quicker.

Balloon disimpaction is usually done immediately before an emergency caesarean, at full dilation, during the second stage of labour.

A disposable soft silicone balloon device is inserted into the vagina, using a lubricant. The balloon is pushed back towards the coccyx and placed between the pelvic floor and the baby's head. The balloon surface is placed in contact with the head. The base plate of the device rests on the posterior vaginal wall and anorectum, opposite the anococcygeal ligament. This is to prevent downward displacement when the device is inflated. Once the device is in position, the balloon is inflated using sterile saline using a tube connected to a 2‑way tap. The balloon is designed to inflate only in an upward direction. Inflating the balloon helps to elevate the head out of the pelvis by a few centimetres. The intention is to:

• make the delivery easier, with less manipulation through the abdominal wound

• reduce the risk of injury.
  
  Immediately after delivery, the balloon is deflated by opening the 2‑way tap and then removed from the vagina by traction. After the caesarean, the vagina is inspected for trauma.