Simple Check Could Transform Millions of Babies’ Lives
Birth is one of the most critical moments in a person’s life. During this transition, a baby moves from receiving oxygen through the umbilical cord to breathing on their own. Most of the time this shift happens smoothly, but when something goes wrong the consequences can be devastating.
We studied over 35,000 babies born in Sweden between 1997 and 2012, tracking their health records for up to 20 years. We found that babies with an umbilical cord pH below 7.05 (suggesting they didn’t get enough oxygen during the delivery) faced a higher risk of death and disabilities within the first two decades of life.
If oxygen deprivation (known as “neonatal acidemia”) lasts too long, it can cause lasting damage to the brain and other organs – and even death. Globally, over a million babies die each year due to oxygen deprivation at birth.
A simple, painless test – namely sampling umbilical cord blood – can check acid levels (pH) to reveal how well the baby handled birth. A low cord pH signals a significant shortage of oxygen during birth, which can lead to a range of complications. However, around the world, doctors can’t agree on what value of cord pH is considered abnormal.
In countries like Sweden and Norway, a cord pH lower than 7.05 is often considered abnormal, reflecting a more cautious approach, while other countries may set the pH threshold at 7.00 or lower to trigger further medical intervention. These differences in guidelines can profoundly affect the timing of interventions and the management of newborns suffering from acidemia at birth.
In our study, the risk of cerebral palsy (a disorder affecting movement and coordination) was four times higher in babies born with a cord pH below 7.05 compared with babies born with a cord pH above 7.05. Similarly, epilepsy (a neurological condition that causes seizures) was nearly twice as likely in babies born with a cord pH of 7.05. The risk of intellectual disabilities was also more common, but only when the cord pH was lower (pH 6.95).
Our study established a clear connection between acidemia at birth and long-term neurological problems. And the lower the cord pH the greater the risk.
The brain is highly sensitive to fluctuating oxygen levels in the blood. Neurons, the brain’s primary communication cells, are particularly vulnerable. If deprived of oxygen, the cells can suffer damage or die, affecting movement, memory and cognitive function.
The brain areas typically affected include the motor cortex , which controls movement and is linked to cerebral palsy; the hippocampus , essential for memory and learning; and the basal ganglia , which regulates movement and can be damaged in oxygen-deprived babies.
If a lack of oxygen is suspected in a newborn, healthcare staff can sample cord pH immediately. Within minutes they can diagnose if the baby’s cord pH is abnormal, allowing for timely medical intervention that can save the baby from long-term brain damage and even death.
Therapeutic hypothermia , or cooling therapy, has shown promise in reducing brain damage when applied during the first hours after birth. Cooling the baby helps slow down the brain’s metabolism, giving the brain time to heal. Medical staff usually cool the baby down to about 33.5°C for about 72 hours before gradually warming the baby back up.
Researchers continue to explore new treatments to protect babies from long-term brain damage.
Recognising the effect of oxygen levels at birth is a medical necessity and a simple blood test can provide us with this information.
Sampling cord pH should be a routine at all maternity units since this test provides a snapshot of the health of the baby at birth. By improving newborn care and medical practices, we can help every child have a better chance at a life, free from preventable disabilities.
Tiia-Marie Sundberg receives funding in the form of a doctoral scholarship from the Southern Healtcare Region in Sweden.
Mehreen Zaigham receives funding from Swedish ALF (ALF is the abbreviation in Swedish of a national agreement between the Swedish government and seven Regions on the education of physicians and clinical research).