Karin Gray, M.D., assistant professor of pediatrics at the Larner College of Medicine (Photo: LCOM Creative Services)
Karin Gray, M.D., is an assistant professor of pediatrics at the Larner College of Medicine at the University of Vermont and a pediatric hospitalist and medical director of the newborn nursery at the University of Vermont Medical Center. Her post, below, originally appeared on the UVM Medical Center blog and was titled “Why Screening for Congenital Heart Disease is Important.”
In pediatrics, February makes us think of Valentine’s Day, cookies, red heart stickers, FROSTING – and American Heart Month. In our newborn nursery, we would like to think that a simple, quick, and almost unnoticed test that newborns receive at 24 hours of life — our critical congenital heart disease screen (CCHD) – is also making parents’ hearts happy.
It has been three years since our nursery first rolled out CCHD screening, led by Rebecca Weston, M.D., in conjunction with the Cindy Ingham, R.N., chief of newborn screening at the Vermont Department of Health. At the same time, hospitals across Vermont also started CCHD screening programs. Additionally, home birthing midwives were given tools to screen infants born by home births.
What is critical congenital heart disease, and why is screening important?
Congenital heart disease affects approximately 1 percent of infants born each year, making it the most common birth defect. The term critical congenital heart disease is used to describe conditions that can be life-threatening and which require intervention in the newborn period.
CCHD accounts for one quarter of all congenital heart disease. Infants with CCHD can have poorer outcomes if there is a delay in diagnosis and treatment. While some of these conditions can be picked up by prenatal ultrasound, others cannot. In a recent 10-year period in Vermont, 42 percent of babies with CCHD were picked up by prenatal ultrasound, while 47 percent were identified after birth by clinical exam. Almost 11 percent of infants with CCHD lesions (totaling 8 babies) were not diagnosed before nursery discharge, or were born at home.
While all of these infants survived, the hope is that CCHD screening can help us identify well-appearing newborns with significant heart disease prior to their leaving the nursery.
How is CCHD screening performed? What can I expect for my newborn?
All infants, when they are first born, have lower levels of oxygen in their blood than adults. This is normal and is due to infants relying on their mother’s oxygen prior to birth. If you’ve seen a newborn, you know that babies look bluish when they are first born and then “pink up.” By the time babies are 24 hours old, their blood oxygen levels should be close to that of an adult.
The pulse ox is a soft cloth or bandage-like strip that is wrapped around a baby’s right hand and either foot to see if baby’s oxygen levels are low, or if the oxygen is being routed abnormally in their body. This can be a clue to critical congenital heart disease – even in a baby who no longer appears “blue.” We like to do this test at 24 hours, to pick up infants as quickly as possible. It can be done earlier, but is more likely to appear abnormal even in a healthy baby, as that baby is still transitioning from in-utero to newborn blood flow patterns.
Wow! CCHD screening sounds amazing!
Yes, we are very happy to think that we are watching out for little hearts in our newborn nursery. However, CCHD screening isn’t perfect. A positive CCHD screen detects problems that are related to the lungs or to infection more often than it detects true heart disease. Or, it detects a newborn that is still transitioning. That is why a first “failed” screen in a well-appearing infant will be followed by up to two more attempts, each an hour later, to give well babies time to mature. Additionally, CCHD screening catches most, but not all infants with CCHD. Parents and primary care providers both remain important in watching over babies as they go home, and bringing babies who need further evaluation to attention.