The ability of doctors to care for newborns with birth defects continues to improve in the US. Babies who may have died from a serious defect decades ago are more likely to survive now.
A recent study found this trend was true particularly with very serious heart defects. The researchers found that more babies born with critical heart defects are surviving today than in the 1980s.
However, almost 20 percent of newborns with very serious heart defects still do not make it to their first birthday.
The researchers found that babies diagnosed a little later actually have a better survival rate overall, perhaps because the heart condition is less severe.
The study, led by Matthew E. Oster, MD, MPH, of the National Center on Birth Defects and Developmental Disabilities at the Centers for Disease Control and Prevention, looked at the long-term survival rates of babies born with heart defects.
The researchers looked at the records of all babies born with congenital heart defects in the greater Atlanta area between 1979 and 2005.
Out of a little over 1 million births, the researchers identified 6,965 babies born with heart defects. Among these, 1,830 had critical congenital heart defects.
Using this data, the researchers estimated the survival rates of the babies who had one of 12 different heart defects at birth.
They also considered when the babies had been diagnosed and what methods had been used to see if earlier diagnosis made a difference in the child's likelihood of surviving.
Out of the children with critical congenital heart defects, 75.2 percent survived to their first birthday, compared to 97.1 percent of those born with noncritical congenital heart defects.
Overall, the survival rate of babies with critical defects improved over time. From 1979 to 1993, the survival rate was 67.4 percent. That increased to 82.5 percent for 1994-2005.
Interestingly, researchers found that babies whose defect was discovered more quickly actually had a lower survival rate.
Among the 890 babies whose critical heart defects were identified within a day or less after birth, 71.7 percent survived. But in the group of 405 babies whose critical heart defect was diagnosed at least one day later after birth, the survival rate was 82.5 percent.
The researchers also found that survival rates for these babies were slightly lower if they had a lower birth weights or if their mothers were under 30 years old.
"One-year survival for infants with critical congenital heart defects has been improving over time, yet mortality remains high. Later diagnosis is associated with improved 1-year survival," the authors wrote.
The authors noted that smaller European studies have found similar results, in which babies whose diagnosis was delayed actually had higher rates of survival.
It's possible that these babies may have less severe defects as well, so it's not clear why the babies with delayed diagnoses are more likely to survive.
The study was published April 22 in the journal Pediatrics. The research did not receive external funding, and the authors declared no conflicts of interest.