Across the United States, more babies born at 22 weeks’ gestation are admitted to neonatal intensive care units (NICUs) and surviving in increasing numbers, according to a new study led by UTHealth Houston. 

The paper, titled “Increasing Resource Use for Infants 22 Weeks’ Gestation in Neonatal Intensive Care Units,” was published today in JAMA Network Open. 

“Over time, our clinical understanding of how to care for preterm infants has changed,” said Matthew Rysavy, MD, PhD, first and corresponding author of the study and assistant professor in the Division of Neonatal-Perinatal Medicine and director of Neonatal Research with McGovern Medical School at UTHealth Houston. “In the 1970s, it was unusual for babies born as early as 28 weeks’ gestation to survive in the United States. Currently, survival is expected for 95% of babies born at 28 weeks’ gestation.” Today, the most premature babies to receive intensive care are born at around 22 weeks’ gestation.

Researchers examined data from the Pediatrix Clinical Data Warehouse on 825,112 infants admitted at 137 tertiary neonatal intensive care units (NICU) across 29 states in the U.S. between 2008 and 2021. Of the 825,112 infants admitted, 60,944 were extremely premature (less than 28 weeks old) and 872 were at 22 weeks’ gestation.

From 2008 to 2021, there was a 388% increase in NICU admissions, 732% increase in bed days, and 946% increase in ventilator days for 22-week-old infants. The number of survivors among infants born at 22 weeks in participating hospitals increased from four per year (2008 to 2009) to 32 per year (2020 to 2021). Researchers theorized that the increase in NICU admissions for infants born at 22 weeks might have been a result of more babies born at that age. But, in fact, the number of births of babies at 22 weeks decreased between 2008 and 2021.

The changes in neonatal intensive care and survival occurred after publication of national guidelines around 2015, according to Rysavy. In 2014-2016, the American Academy of Pediatrics, American College of Obstetricians and Gynecologists, and others published updated guidance to support intensive care as early as 22 weeks’ gestation in appropriate clinical circumstances.

“This is an example of medical practice changing. Infants born at 22 weeks’ currently account for 1 in 16 U.S. infant deaths, but that appears to be decreasing with changes in practice,” Rysavy said.

Co-authors included Monica M. Bennett, PhD, with Baylor Scott & White Research Institute; Ravi M. Patel, MD, MSc, with Emory University and Children’s Healthcare of Atlanta; Zubin S. Shah, MD, with Baylor University Medical Center, Texas A&M Health Science Center School of Medicine and Pediatrix Medical Group; Kaashif A. Ahmad, MD, with the University of Houston, Women’s Hospital of Texas and Pediatrix Medical Group; Dan L. Ellsbury, MD, with Mercy One Children’s Hospital and Pediatrix Medical Group; Veeral N. Tolia, MD, with Baylor University Medical Center and Pediatrix Medical Group; and Reese H. Clark, MD, with Pediatrix Medical Group and the Pediatrix Center for Research Education, Quality, and Safety. (RJ/Newswise)