Editor’s Note: Dr. Julie Evans (she/her) is a resident physician in pediatrics at the University of Virginia. She is interested in general pediatrics and global health. – Rachel Y. Moon, MD, Associate Editor, Digital Media, Pediatrics
“Preterm,” “very preterm,” “early term,” and “term” are all words we use to describe how long the gestation (pregnancy) has been when a baby is born. Very preterm infants are those who are born before 28 weeks’ gestation.
Unsurprisingly, when a baby is born very preterm, many morbidities (diseases that can cause long term consequences) and even mortality (death) are more common. Dr. Jeffrey D. Horbar, MD, and colleagues from the University of Vermont analyzed data from the Vermont Oxford Network for 447,396 very preterm infants at 888 US hospitals to describe trends over time in outcomes for these infants in their article entitled, “Trends in Mortality and Morbidities for Infants Born 24 to 28 Weeks in the US: 1997-2021,” which is being early released this week in Pediatrics (10.1542/peds.2023-064153).
This study included very preterm infants born at 24–28 weeks’ gestation who weighed 401 to 1500 grams (0.88–3.3 pounds) at birth. The authors examined trends in mortality and the following morbidities: late onset sepsis, necrotizing enterocolitis (NEC), chronic lung disease (CLD), intraventricular hemorrhage (IVH), and retinopathy of prematurity (ROP). In addition, the authors looked at the category of death or morbidity, which was defined as an infant dying or having at least one of the morbidities above.
The authors found that from 1997 to 2021:
- Rate of mortality decreased (18.1% to 12.4%)
- Rate of late onset sepsis decreased (32.4% to 13.4%)
- Rate of NEC decreased (10% to 6.8%)
- Rate of CLD increased (33.4% to 43.3%)
- Rate of severe IVH decreased (11.8% to 10.7%)
- Rate of severe ROP decreased (14.8% to 9.3%)
The overall rate of death or morbidity also decreased from 65.4% to 57.6%.
However, when the authors analyzed the data by clustering years in smaller groups, they discovered that improvements in mortality and morbidity have slowed, stalled, or even reversed in recent years. Nearly all of the morbidities had rapid improvement early on, with slower or no improvement in more recent years. The authors speculate that the early improvements observed may have been due to quality improvement by neonatal care teams and the start of effective therapies that are now being used for most infants. The authors propose that we may have reached the limit of effectiveness of available therapies such as antenatal steroids, surfactant administration, and non-invasive ventilation.
In order to regain the pace of improvement seen in the earlier years of this study, the authors propose a 3-pronged strategy:
- Research to develop new therapies
- Quality improvement to optimize effectiveness of available interventions
- Commitment to follow through addressing social determinants of health
Regardless of subspecialty, most pediatricians care for children who were born very preterm, and this article will remind all of us of how far treatment for these smallest infants has progressed over the past few decades.
