More must be done to prevent serious illness and death which can occur among some larger-than-average babies if their shoulders get stuck during birth, a watchdog has warned.

A new maternity investigation by the Healthcare Safety Investigation Branch (HSIB) highlighted a “time-critical” emergency associated with shoulder dystocia during the birth of some larger babies.

The problem can cause babies to suffer severe brain injury, nerve damage, or even die.

Investigators examined 31 reports including two instances where babies died during birth due to shoulder dystocia.

Another died shortly after birth from other health conditions, and 28 were treated in neonatal intensive care units with therapeutic cooling – a procedure where a baby is cooled to between 33C and 34C with the aim of preventing further brain injury following a hypoxic injury, or a lack of oxygen.

The report states that 22 of the 31 babies weighed more than 4,000g at birth – only around 10% of babies nationally weigh this much when they are born.

HSIB said that there are many challenges in how larger than average babies are identified and the subsequent management of care of the mother during pregnancy.

Sandy Lewis, director of maternity investigations at HSIB, said: “In the majority of cases of shoulder dystocia, babies do not sustain long term harm.

“However, in the 31 cases we examined, shoulder dystocia has sadly contributed to nerve damage, brain injury and, rarely death.

“The emergency nature of this also adds to the distress and trauma felt by the families and staff involved.

“In this national learning report, we emphasised that national guidance that supports consistent and effective processes of identifying larger than average gestational age babies and managing the mother’s care is crucial in reducing those risks, and aids planning for labour and birth.”

It is estimated that shoulder dystocia affects between 0.58% and 0.70% of births.