Gestational age and weight at discharge for infants aged 24-29 weeks increased steadily between 2005 and 2018, reported Erika M. Edwards, PhD, MPH, of the Vermont Oxford Network, Burlington, and associates.
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Although they discussed several possible influencing factors, the authors were unable to explain the associated benefits, costs, and harms associated with increased age and weight at discharge, which remain undetermined. Infants are separated a week longer than they were at the beginning of the study period, the prolonged effects of which cannot be underestimated, Dr. Edwards and colleagues observed in a large cohort study in Pediatrics.
A total of 314,811 infants 24-29 weeks’ gestational age who were admitted to 824 neonatal ICUs (NICUs) throughout the United States survived to initial discharge. The median postmenstrual age at hospital discharge was 38.3 weeks. Over the 14-year period from 2005 to 2018, unadjusted postmenstrual age at discharge increased a median 9 days, compared with a median adjusted age of 8 days.
Of the 273,109 infants initially discharged from the hospital to home, median weight at discharge was 2,600 g. Over the 14 years from 2005 to 2018, median unadjusted discharge weight increased 360 g, compared with median adjusted weight, which was estimated to have increased 316 g.
Median unadjusted z scores for weight increased 0.22 standard units over the 14-year period, compared with median adjusted z scores for weight at discharge, which increased an estimated 0.19 standard units.
The proportion of infants who were consuming human milk at discharge increased over the study period from 40% in 2005 to 48% in 2018. The use of cardiorespiratory monitors and oxygen decreased from 49% to 26%, and 27% to 22% respectively. The number of infants who were never transferred to specialized care before discharge to home also improved, from 71% to 76%.
Despite the unknowns, good news for managing pediatricians?
In a separate interview, study author Dr. Edwards noted that “infants born very preterm, who are discharged home from the NICU today, are larger and more physiologically mature than they were in 2005. Pediatricians will likely find this news to be positive as it may be easier to manage care for a more physiologically mature [infant],” and it may reduce risk of readmission.
“Infants stayed, on average, 8 days longer in 2018 than they did in 2005. That is 8 days when they were not at home with their families. Despite efforts by NICU teams to increase family-centered care, the NICU is not the same as being at home. ... That extra time in the NICU cost [some families] an estimated $28,000. ... As health care costs continue to rise, we need to understand the true cost [behind] this increase,” added Dr. Edwards, noting that more research is needed to understand what may be driving the increase in NICU length of stay and the possible implications. More research to investigate whether babies did better after discharge also is needed.
Going forward, Dr. Edwards indicated that she and her colleagues are exploring ways to measure apnea of prematurity (AOP) and use of continuous pulse oximetry (CPO) as the subject of future studies. In our study, we showed that the number of infants discharged home on a cardiorespiratory monitor decreased, but we do not know if that is explained by differences in management of AOP and CPO. “Understanding the influence of AOP and CPO management on discharge age would be an important contribution [to future research].”