Meta-Analysis in PEDIATRICS: Survival and Impairment of Extremely Premature Infants

Reference: Hilde Tinderholt Myrhaug, Kjetil Gundro Brurberg, Laila Hov, Trond Markestad. (2019). Survival and Impairment of Extremely Premature Infants: A Meta-analysisPediatrics, Feb 2019, 143 (2) e20180933; DOI: 10.1542/peds.2018-0933

CONTEXT: Survival of infants born at the limit of viability varies between high-income countries.

OBJECTIVE: To summarize the prognosis of survival and risk of impairment for infants born at 22 + 0/7 weeks’ to 27 + 6/7 weeks’ gestational age (GA) in high-income countries.

DATA SOURCES: We searched 9 databases for cohort studies published between 2000 and 2017 in which researchers reported on survival or neurodevelopmental outcomes.

STUDY SELECTION: GA was based on ultrasound results, the last menstrual period, or a combination of both, and neurodevelopmental outcomes were measured by using the Bayley Scales of Infant Development II or III at 18 to 36 months of age.

DATA EXTRACTION: Two reviewers independently extracted data and assessed the risk of bias and quality of evidence.

RESULTS: Sixty-five studies were included. Mean survival rates increased from near 0% of all births, 7.3% of live births, and 24.1% of infants admitted to intensive care at 22 weeks’ GA to 82.1%, 90.1%, and 90.2% at 27 weeks’ GA, respectively. For the survivors, the rates of severe impairment decreased from 36.3% to 19.1% for 22 to 24 weeks’ GA and from 14.0% to 4.2% for 25 to 27 weeks’ GA. The mean chance of survival without impairment for infants born alive increased from 1.2% to 9.3% for 22 to 24 weeks’ GA and from 40.6% to 64.2% for 25 to 27 weeks’ GA.

LIMITATIONS: The confidence in these estimates ranged from high to very low.

CONCLUSIONS: Survival without impairment was substantially lower for children born at <25 weeks’ GA than for those born later.