J Korean Med Sci.  2016 Nov;31(11):1797-1801. 10.3346/jkms.2016.31.11.1797.

Seasonal Pattern of Preterm Births in Korea for 2000–2012

• Woo Y
• Ouh YT
• Ahn KH
• Cho GJ
• Hong SC
• Oh MJ
• Kim HJ

• KMID: 2470277
• DOI: http://doi.org/10.3346/jkms.2016.31.11.1797

Abstract

The aim of this study was to investigate a seasonal pattern of preterm births in Korea. Data were obtained from the national birth registry of the Korean Statistics Office and included all births in Korea during the period 2000-2012 (n = 6,310,800). Delivery dates were grouped by month of the year or by season (winter [December, January, February], spring [March, April, May], summer [June, July, August], and autumn [September, October, November]). The seasonal patterns of prevalence of preterm births were assessed. The rates of preterm births at 37 weeks were highest twice a year (once in winter and again in summer). The rates of preterm births increased by 13.9% in summer and 7.5% in winter, respectively, than in spring (OR, 1.139; 95% CI, 1.127-1.152, and OR, 1.075; 95% 1.064-1.087, respectively) after controlling for age, the educational level of the parents, maternal parity, and neonatal gender. The pattern for spontaneous preterm births < 34 weeks was similar. In Korea, a seasonal pattern of preterm births was observed, with peak prevalence in summer and winter. A seasonal pattern of preterm births may provide new insights for the pathophysiology of preterm births.

Keyword

Seasonal Variation; Preterm Birth; Summer; Winter, Korea

MeSH Terms

Adult
Female
Humans
Infant, Newborn
Logistic Models
Male
Odds Ratio
Premature Birth/*epidemiology
Prevalence
Republic of Korea/epidemiology
Seasons
Young Adult

Figure

• 

  Fig. 1 The rate of preterm births by seasons at delivery. (A) < 37 weeks, (B) < 34 weeks.

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