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Comparative Study
. 2019 Mar 26;321(12):1188-1199.
doi: 10.1001/jama.2019.2021.

Association Between Year of Birth and 1-Year Survival Among Extremely Preterm Infants in Sweden During 2004-2007 and 2014-2016

Mikael Norman  1   2   3 , Boubou Hallberg  1   2 , Thomas Abrahamsson  4 , Lars J Björklund  5 , Magnus Domellöf  6 , Aijaz Farooqi  6 , Cathrine Foyn Bruun  6 , Christian Gadsbøll  4   5 , Lena Hellström-Westas  7 , Fredrik Ingemansson  8 , Karin Källén  9 , David Ley  5 , Karel Maršál  10 , Erik Normann  7 , Fredrik Serenius  7 , Olof Stephansson  11   12 , Lennart Stigson  13 , Petra Um-Bergström  14   15 , Stellan Håkansson  3   6
Affiliations
Comparative Study

Association Between Year of Birth and 1-Year Survival Among Extremely Preterm Infants in Sweden During 2004-2007 and 2014-2016

Mikael Norman et al. JAMA. .

Erratum in

Abstract

Importance: Since 2004-2007, national guidelines and recommendations have been developed for the management of extremely preterm births in Sweden. If and how more uniform management has affected infant survival is unknown.

Objective: To compare survival of extremely preterm infants born during 2004-2007 with survival of infants born during 2014-2016.

Design, setting and participants: All births at 22-26 weeks' gestational age (n = 2205) between April 1, 2004, and March 31, 2007, and between January 1, 2014, and December 31, 2016, in Sweden were studied. Prospective data collection was used during 2004-2007. Data were obtained from the Swedish pregnancy, medical birth, and neonatal quality registries during 2014-2016.

Exposures: Delivery at 22-26 weeks' gestational age.

Main outcomes and measures: The primary outcome was infant survival to the age of 1 year. The secondary outcome was 1-year survival among live-born infants who did not have any major neonatal morbidity (specifically, without intraventricular hemorrhage grade 3-4, cystic periventricular leukomalacia, necrotizing enterocolitis, retinopathy of prematurity stage 3-5, or severe bronchopulmonary dysplasia).

Results: During 2004-2007, 1009 births (3.3/1000 of all births) occurred at 22-26 weeks' gestational age compared with 1196 births (3.4/1000 of all births) during 2014-2016 (P = .61). One-year survival among live-born infants at 22-26 weeks' gestational age was significantly lower during 2004-2007 (497 of 705 infants [70%]) than during 2014-2016 (711 of 923 infants [77%]) (difference, -7% [95% CI, -11% to -2.2%], P = .003). One-year survival among live-born infants at 22-26 weeks' gestational age and without any major neonatal morbidity was significantly lower during 2004-2007 (226 of 705 infants [32%]) than during 2014-2016 (355 of 923 infants [38%]) (difference, -6% [95% CI, -11% to -1.7%], P = .008).

Conclusions and relevance: Among live births at 22-26 weeks' gestational age in Sweden, 1-year survival improved between 2004-2007 and 2014-2016.

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Conflict of interest statement

Conflict of Interest Disclosures: Dr Norman reported receiving grants from the Swedish Heart Lung Foundation and the H2020/European Union; and receiving personal fees from a Swedish medical journal, the Swedish patient insurance, Liber AB, Studentlitteratur AB, and AbbVie AB. No other disclosures were reported.

Figures

Figure.
Figure.. One-Year Survival Among Infants Delivered at 22-26 Weeks’ Gestational Age in Sweden
Infants were born between April 1, 2004, and March 31, 2007, in the Extremely Preterm Infants in Sweden Study (EXPRESS) and between January 1, 2014, and December 31, 2016, in EXPRESS 2. The observation time was 1 year for all infants during both studies. The vertical ticks at the ends of the lines are 95% CIs. The lines are staggered to avoid superimposition.
See this image and copyright information in PMC

Comment in

References

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