J Korean Med Assoc.  2016 Jul;59(7):498-505. 10.5124/jkma.2016.59.7.498.

Changes in neonatal outcomes in Korea

• Kim SY

• KMID: 2343860
• DOI: http://doi.org/10.5124/jkma.2016.59.7.498

Abstract

In Korea, the first neonatal intensive care unit was established in the early 1980s, and over the past 30 years, the advancements in the field of neonatology in Korea have led to a significant improvement in the survival of low birth weight infants. The survival rates of very low birth weight infants (VLBWIs) more than doubled, from 38.3% in the 1980s to 84.8% in 2014, and the survival rates of extremely low birth weight infants increased more than five-fold, from 12.3% in the 1980s to 69.6% currently. A comparison of VLBWI survival among countries showed improved survival rates in each birth weight group in Canada, Australia-New Zealand, and various European countries, with Japan at the top. For the first time in Korea, a nationwide prospective web-based registration system for VLBWIs, the Korean Neonatal Network (KNN), was established, and KNN operations were initiated officially on April 15, 2013 by the Korean Society of Neonatology with support from the Korea Centers for Disease Control and Prevention. As of April 2016, clinical data for over 6,700 VLBWIs have been collected from 64 participating hospitals across the country. This network has made it possible to investigate overall survival rates as well as short- and long-term outcomes in VLBWIs. The purpose of this review was to evaluate the recent changes in neonatal outcomes in VLBWIs in Korea based on KNN data.

Keyword

Infant, very low birth weight; Infant, extremely low birth weight; Mortality; Morbidity; Outcomes

MeSH Terms

Birth Weight
Canada
Centers for Disease Control and Prevention (U.S.)
Humans
Infant
Infant, Extremely Low Birth Weight
Infant, Low Birth Weight
Infant, Newborn
Infant, Very Low Birth Weight
Intensive Care, Neonatal
Japan
Korea*
Mortality
Neonatology
Prospective Studies
Survival Rate

Figure

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  Figure 1 Changes of neonatal survival rates for very low birth weight infants (VLBWI) and extremely low birth weight infants (ELBWI) in Korea (1960-2014 June) (From Shim JW, et al. J Korean Med Sci 2015;30 Suppl 1:S25-S34, according to the Creative Commons license) [3].

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  Figure 2 Changes of neonatal survival rates by gestational period in Korea (2002-2014 June). *P<0.015, 2007 vs. 2002; †P<0.015, 2009 vs. 2002; ‡P<0.015, 2013-2014.6 vs. 2002 (From Shim JW, et al. J Korean Med Sci 2015;30 Suppl 1:S25-S34, according to the Creative Commons license) [3].

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  Figure 3 Comparison of neonatal survival rate in Korea, Japan, Europe, Canada, and Autralia-New Zealand by very low birth weight infants (VLBWIs) and extremely low birth weight infants (ELBWIs). *P<0.05 comparison to the Korean Neonatal Network (KNN) reference birth weight specific survival rates. NRNJ, Neonatal Research Network of Japan [12]; CNN, Canadian Neonatal Network [13]; AZN, Australia-New Zealand Neonatal Network [14]; EuroNeo-Net, European Neonatal Network [15] (From Shim JW, et al. J Korean Med Sci 2015;30 Suppl 1:S25-S34, according to the Creative Commons license) [3].

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  Figure 4 Changes of the rate of death before 36 weeks, survival with bronchopulmonary dysplasia (BPD) or survival without BPD at 36 weeks postmenstrual age (PMA) from 2013 to mid 2014 compared to 2007 to 2008 [10] among very low birth weight (VLBW) infants born at 23 to 31 weeks of gestation. In total, 1,990 VLBW infants were compared to 3,841 VLBW infants from the nationwide survey in 2007 to 008 [18]. The distribution of the overall rate of the three possible outcomes at 36 weeks PMA were different compared to that in the survey from 2007 to 2008 [18] using the chi-square test (P<0.001). The incidence of BPD increased by 85% (from 17.8% to 33.0%); the rate of severe BPD increased by 157% (from 8.1% to 20.8%); the rate of death before 36 weeks' PMA decreased by 28.9% (from 15.9% to 11.3%) compared to the retrospective survey in 2007 to 2008 [18] (From Jo HS, et al. J Korean Med Sci 2015;30 Suppl 1:S81-S87, according to the Creative Commons license) [19].

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  Figure 5 Incidence of intraventricular hemorrhage (IVH) according to gestational age (GA) (A) and birth weight (BW) (B). The proportions of infants with grades 1, 2, 3, and 4 IVH and without IVH are presented according to GA and BW (From Ahn SY, et al. J Korean Med Sci 2015;30 Suppl 1:S52-S58, according to the Creative Commons license) [20].

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  Figure 6 Ecrotizing enterocolitis (NEC) incidence according to gestational age (week) (From Youn YA, et al. J Korean Med Sci 2015;30 Suppl 1:S75-S80, according to the Creative Commons license) [23].

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  Figure 7 The incidences of severity of retinopathy of prematurity (ROP) and treatment according to the gestational age and birth weight in very low birth weight infants. (A) The incidences of severity of ROP and treatment according to gestational age. (B) The incidences of severity of ROP and treatment according to birth weight (From Hwang JH, et al. J Korean Med Sci 2015;30 Suppl 1:S88-S94, according to the Creative Commons license) [24].

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