What Are The Limits of (Preterm) Viability?

A retrospective recent study (PL Watkins et al. J Pediatr 2020; 217: 52-8) provides data that suggests that preterm infants at 22-23 weeks gestation can have good outcomes.


  • n=70 for 22-23 weeks (22 weeks, n=20, 23 weeks, n=50)
  • n=178 for 24-25 weeks (24 weeks, n=79, 25 weeks, n=99)

Key findings:

  • Survival to hospital discharge: 78% for 22-23 week cohort, 89% for 24-25 week cohort
  • No or mild neurodevelopmental impairment 64% or 22-23 week cohort, 76% for 24-25 week cohort. This was based on prospectively collected data at 18-22 months with Bayley Scales (BSID-III) (≥85) and being free from vision and hearing impairment

These survival and neurodevelopmental outcomes far exceed previous reports.  The study and the associated editorial (pg 9) identify several treatment characteristics that could have helped optimize outcomes: antenatal steroids, high-frequency ventilation, and a specialized environment.  Also, the authors did not include infants who were outborn, stillborn or died in the delivery room.

My take: This article’s data needs to be replicated elsewhere; in the meanwhile, it is going to challenge the notion of nihilism for infants born at 22-23 weeks gestation.

Related article: AH Jobe. J Pediatr 2020; 217: 184-8.  This commentary discusses the potential lifetime consequences of antenatal steroids, which may affect neurodevelopment and cardiovascular outcomes. “Antenatal corticosteroids are frequently used to disrupt normal development in rodent models”

Related blog posts:

St Thomas Harbor

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