Survival of Infants Born at Periviable Gestational Ages

https://doi.org/10.1016/j.clp.2017.01.009Get rights and content

Section snippets

Key points

  • Estimates of gestational age–specific survival vary significantly across hospitals, regions, and countries and are influenced by a number of factors that can make unbiased comparisons challenging.

  • Survival among live periviable births at 22 to 25 weeks of gestation has incrementally improved since the 1950s, with continued gains over the past decade.

  • Provision of active treatment, particularly at 22 and 23 weeks of gestation, varies widely among centers and countries, and this variation has a

Historical perspectives

The survival of extremely low birth weight (ELBW; birth weight ≤1000 g) infants, including periviable infants, has improved consistently over the past 7 decades. In the 1940s, death was the expected outcome for all ELBW infants born in developed nations around the world.3 Beginning in the 1950s and 1960s, the probability of survival for ELBW infants among several centers in the United States and the United Kingdom increased to 10% to 30% as understanding of neonatal physiology improved and the

Estimates of gestational age–specific survival

During the past 5 years, large cohort studies from developed nations in North America,11, 12, 13, 20, 21 South America,22 Europe,14, 15, 23, 24, 25 Asia,18, 19, 26 and Australia27 have reported estimates of gestational age–specific survival following periviable birth. Direct comparisons of estimated survival rates among these studies are limited, however, by potential biases introduced from differences in the data sources, ascertainment of death, selection of denominators, and definitions of

Recommendations and guidelines for perinatal care

Some of the variation in survival observed in Fig. 2 may be attributable to variation in the approach to perinatal care based on guideline statements from professional organizations and scientific societies. In a systematic review of 31 national or international guidelines for perinatal care of periviable births in highly developed countries, there was substantial variation in recommendations. Sixty-eight percent of guideline statements supported comfort care at 22 weeks of gestation and 65%

Cohort Selection

Differences in the conduct of cohort studies are important to understand when interpreting and comparing gestational age–specific survival rates. This is particularly relevant when studies use different numerators (eg, death in the delivery room, death before 28 days, death before hospital discharge, death before 1 year) and denominators (eg, fetus alive at maternal admission and >20 weeks of gestation, all live births, inborn live births, live births receiving active treatment, infants

Summary

In conclusion, survival among periviable births has improved since the 1950s, including over the past decade. There is wide variation in survival of periviable live births across developed countries and across different NICUs in the same country, although estimates of gestational age–specific survival are influenced by a number of factors that limit unbiased comparisons. Provision of active treatment, particularly at 22 and 23 weeks of gestation, varies widely among hospitals and developed

Acknowledgments

The review was supported, in part, by the National Institutes of Health under award K23 HL128942 (R.M. Patel). The authors would like to acknowledge the NICHD Neonatal Research Network, including Rosemary Higgins, MD, Abhik Das, PhD, and the GDB subcommittee, for graciously providing recent data on periviable survival.

First page preview

First page preview
Click to open first page preview

References (83)

  • A.A. Verhagen et al.

    Categorizing neonatal deaths: a cross-cultural study in the United States, Canada, and The Netherlands

    J Pediatr

    (2010)
  • T.N. Raju et al.

    Periviable birth: executive summary of a joint workshop by the Eunice Kennedy Shriver National Institute of Child Health and Human Development, Society for Maternal-Fetal Medicine, American Academy of Pediatrics, and American College of Obstetricians and Gynecologists

    Obstet Gynecol

    (2014)
  • American College of Obstetricians and Gynecologists, Society for Maternal-Fetal Medicine et al.

    Periviable birth: interim update

    Am J Obstet Gynecol

    (2016)
  • A.L. Stewart et al.

    Outcome for infants of very low birthweight: survey of world literature

    Lancet

    (1981)
  • R. Bhat et al.

    Immediate and long-term outcome of infants less than 1000 grams

    Crit Care Med

    (1978)
  • N. Paneth et al.

    Newborn intensive care and neonatal mortality in low-birth-weight infants: a population study

    N Engl J Med

    (1982)
  • R.R. Gordon

    Neonatal and “perinatal” mortality rates by birth weight

    Br Med J

    (1977)
  • K. Costeloe et al.

    The EPICure study: outcomes to discharge from hospital for infants born at the threshold of viability

    Pediatrics

    (2000)
  • B.J. Stoll et al.

    Neonatal outcomes of extremely preterm infants from the NICHD Neonatal Research Network

    Pediatrics

    (2010)
  • B.J. Stoll et al.

    Trends in care practices, morbidity, and mortality of extremely preterm neonates, 1993-2012

    JAMA

    (2015)
  • R.M. Patel et al.

    Causes and timing of death in extremely premature infants from 2000 through 2011

    N Engl J Med

    (2015)
  • J.D. Horbar et al.

    Mortality and neonatal morbidity among infants 501 to 1500 grams from 2000 to 2009

    Pediatrics

    (2012)
  • K.L. Costeloe et al.

    Short term outcomes after extreme preterm birth in England: comparison of two birth cohorts in 1995 and 2006 (the EPICure studies)

    BMJ

    (2012)
  • P.Y. Ancel et al.

    Survival and morbidity of preterm children born at 22 through 34 weeks' gestation in France in 2011: results of the EPIPAGE-2 cohort study

    JAMA Pediatr

    (2015)
  • P.S. Shah et al.

    Outcomes of preterm infants <29 weeks gestation over 10-year period in Canada: a cause for concern?

    J Perinatol

    (2012)
  • S. Kusuda et al.

    Trends in morbidity and mortality among very-low-birth-weight infants from 2003 to 2008 in Japan

    Pediatr Res

    (2012)
  • N. Ishii et al.

    Outcomes of infants born at 22 and 23 weeks' gestation

    Pediatrics

    (2013)
  • W.J. Ge et al.

    Prediction of neonatal outcomes in extremely preterm neonates

    Pediatrics

    (2013)
  • R. Guinsburg et al.

    Proactive management of extreme prematurity: disagreement between obstetricians and neonatologists

    J Perinatol

    (2012)
  • F. Serenius et al.

    Neurodevelopmental outcome in extremely preterm infants at 2.5 years after active perinatal care in Sweden

    JAMA

    (2013)
  • F. Chen et al.

    Thirteen-year mortality and morbidity in preterm infants in Switzerland

    Arch Dis Child Fetal Neonatal Ed

    (2016)
  • M.J. Zegers et al.

    Changing Dutch approach and trends in short-term outcome of periviable preterms

    Arch Dis Child Fetal Neonatal Ed

    (2016)
  • P. Agarwal et al.

    Neonatal outcome of extremely preterm Asian infants 28 weeks over a decade in the new millennium

    J Perinatol

    (2015)
  • R.A. Boland et al.

    Outcomes of infants born at 22-27 weeks' gestation in Victoria according to outborn/inborn birth status

    Arch Dis Child Fetal Neonatal Ed

    (2017)
  • U. Guillen et al.

    Survival rates in extremely low birthweight infants depend on the denominator: avoiding potential for bias by specifying denominators

    Am J Obstet Gynecol

    (2011)
  • M.A. Rysavy et al.

    Reporting outcomes of extremely preterm births

    Pediatrics

    (2016)
  • U. Guillen et al.

    Guidelines for the management of extremely premature deliveries: a systematic review

    Pediatrics

    (2015)
  • M.A. Hernan et al.

    The Simpson's paradox unraveled

    Int J Epidemiol

    (2011)
  • P.J. Marang-van de Mheen et al.

    Simpson's paradox: how performance measurement can fail even with perfect risk adjustment

    BMJ Qual Saf

    (2014)
  • B.N. Manktelow et al.

    Differences in case-mix can influence the comparison of standardised mortality ratios even with optimal risk adjustment: an analysis of data from paediatric intensive care

    BMJ Qual Saf

    (2014)
  • A. Janvier et al.

    Delivery room practices for extremely preterm infants: the harms of the gestational age label

    Arch Dis Child Fetal Neonatal Ed

    (2016)
  • Cited by (112)

    View all citing articles on Scopus

    Conflicts of Interest: The authors have no conflicts of interest to report.

    View full text