For every 4000 babies born, one baby will be born with lungs so underdeveloped (Congenital Diaphragmatic Hernia) that they will die soon after birth, or, if they survive, they will face lifelong neurological and respiratory problems.

Despite the physical limitation of being born with small lungs, promising research is showing that these babies may have a greater chance of survival if the clamping of their umbilical cord is delayed.

Overcoming congenital diaphragmatic hernia

The condition faced by these newborns is called congenital diaphragmatic hernia (CDH). For babies with CDH, a hole forms in their diaphragm early in their fetal development.

This hole allows the baby’s stomach and intestines to move into their chest, preventing their lungs from growing. When they are born, their lungs are often too small sustain life without considerable medical assistance.

While these babies are in the womb, their small lungs do not cause them difficulty because they are sustained by oxygen from their mother’s placenta, delivered via the umbilical cord.

However, the transition from fetal to neonatal life is particularly difficult for babies with CDH: immediately clamping the umbilical cord at birth forces these babies to become entirely reliant on their underdeveloped lungs for oxygen.

The benefits of delayed cord clamping

Hudson Institute’s research has found that if umbilical cord clamping is delayed until after a newborn has filled its lungs with air (physiologically based cord clamping), then oxygen delivery to the brain is maintained at safe levels during the transition to newborn life.

Fetal and Neonatal Health PhD student Aidan Kashyap likens a baby’s umbilical cord to a scuba diver’s life-sustaining tank of oxygen.

“Clamping the umbilical cord before a baby is ready to breathe is like disconnecting a scuba diver’s oxygen tank before they have reached the surface,” he said.

“With physiologically based cord clamping, we wait until the baby is ready to breathe before disconnecting them from the life-support of mum’s placenta.”

Mr Kashyap also said that this more stable transition to newborn life is also associated with better blood flow through the lungs for at least the first two hours after birth.

Delayed clamping for babies requiring resuscitation

While the World Health Organization already recommends delayed cord clamping for all healthy babies, this practise hasn’t been seen as feasible for babies requiring resuscitation at birth. This is because the resuscitation equipment is in the corner of the delivery room, away from the mother.

However, several clinical studies have now demonstrated the feasibility of using innovative devices to assess, resuscitate and ventilate infants at the maternal bedside, including the Baby-DUCC trial for pre-term babies, led by Dr Douglas Blank at Monash Children’s Hospital.

International collaboration in the works

From the success of these pre-clinical studies for CDH, alongside the clinical studies showing the possibilities of resuscitating infants at the maternal bedside, Mr Kashyap says taking the next step in furthering cord clamping research is on the horizon.

“Our current study suggests that the benefits of physiologically based cord clamping also extend to babies with CDH, so we are working closely with international collaborators to develop a clinical trial specifically for these infants with CDH,” he said.

Read the full report in BMJ Journals, titled Physiologically based cord clamping improves cardiopulmonary haemodynamics in lambs with a diaphragmatic hernia.

CDH Australia supports families affected by congenital diaphragmatic hernia. Information about support services is available on their website, www.cdh.org.au

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