Freezing The Baby: The Novel Therapy That Took Neonatology By Storm

By Eva Martin, MD of Elm Tree Medical Inc.

Modern medicine is full of wonders, from mechanical ventilators that enable tiny preemies to breathe when their lungs are too small to catheters that deliver all the nutrition a neonate needs to survive the first few weeks. Advances in modern medicine, and particularly in technologies and treatments in the Neonatal Intensive Care Unit (NICU), have drastically increased survival rates. Take the same infant born at 1,000 grams birthweight (2.2 pounds). In 1960, that newborn had a 5% chance of living. In 2000, she had a 95% chance. As advances have enabled more infants to survive this critical period, attention has been directed towards interventions that will improve their long-term outcomes and reduce neurologic disability. Chief amongst these therapies is “therapeutic hypothermia” also known as “head cooling.” What is this intervention and who does it work for?

Therapeutic hypothermia can involve cooling either a premature infant’s head or whole body. Some hospitals cool the whole body because it leaves the baby’s head free so physicians can monitor brain activity with EEG sensors. In either case, therapeutic hypothermia involves cooling a newborn to a core temperature of 92.3 to 94.1 degree Fahrenheit (really cold!) for three days. Researchers have studied various methods and have established a set of best practices, such as starting therapy within 6 hours of birth and conducting various monitoring tests like EEG, MRI, and ultrasound.

You may be thinking- this treatment sounds very dramatic! This can’t possibly be for all preemies! You’re right- therapeutic hypothermia is for any infant who meets the following three criteria: Gestational age >33 weeks, suspicion of encephalopathy or a seizure event, and any obstetric sentinel event. Examples of obstetric sentinel events include a concerning fetal heart tracing during labor, a low APGAR score 10 minutes after birth, or placental abruption. Doctors may suspect encephalopathy when they observe lethargy, weak or missing reflexes, constricted pupils, low heart rate, or difficulty breathing, among other signs. When doctors first started researching therapeutic hypothermia, the indications were much more restricted, but further research has led many centers to offer this treatment to more infants who could potentially benefit. 1 in 300 newborns are diagnosed with encephalopathy.

Does this dramatic therapy really work? Yes. The chance a neonate survived with a normal neurodevelopmental outcome at 18 months increased from 23% to 40% with therapeutic hypothermia. Two meta-analyses demonstrated that therapeutic hypothermia reduces the risk of death and major neurodevelopmental disability for infants. A Cochrane review systematically evaluated each of the purported benefits of therapeutic hypothermia and found a statistically significant lowering of the risk of neuromotor delay, developmental delay, cerebral palsy, and abnormal MRI results. It also resulted in a non-significant reduction in deafness and blindness. Side effects included low heart rate and high platelet count.

If a baby needs this miraculous intervention, does it mean that something went wrong during labor? Not necessarily. Obviously every case is different, but research has shown that less than 50% of encephalopathy cases are due to management of labor. As this intervention is available for more infants, more obstetricians will have the role of explaining this therapy to their patients and supporting new parents during this stressful and uncertain time. We want to hear from you! Does your hospital offer therapeutic hypothermia? Have you seen its results first hand?