Secular Trends of Preterm Birth Rate in Primiparous Women by Matermal Age: 1997~1999, 2011~2013 Singleton Birth Certificated Data of Korea |
박상화1, 임달오2 |
1서울대학교 의학연구원 인구의학연구소 2국립공주대학교 보건행정학과 |
우리나라 초산부의 출산 연령에 따른 단태아 조기분만율추이에 관한 연구, 1997~1999, 2011~2013 |
박상화1, 임달오2 |
1서울대학교 의학연구원 인구의학연구소 2국립공주대학교 보건행정학과 |
|
Abstract |
Purpose The objective of the study was to compare the secular trend of age specific preterm birth (PTB) rate by analyzing singleton birth certificated data among primiparous women (1997~ 1999: 918,115 births, 2011~2013: 690,120 births) of Korea Statistics.
Methods Odds ratio and 95% confidence intervals were calculated from logistic regression analyses to describe the secular trend (1997~1999 and 2011~2013) of maternal age specific PTB rate (20~24, 25~29, 30~34, 35~39, ≥40) adjusted for infantile sex, maternal education & occupation, and marital status.
Results The incidence of PTB increased 2.9 percent in 1997~1999 (phase I) to 4.4 percent in 2011~2013 (phase II). Age standardized PTB rate rose from 3.2 percent to 4.2 percent during the period. Compared with age specific PTB rates of phase I, the odds ratio of PTB in birth year of phase II were 1.636 (95% confidence interval: 1.550~1.726) in aged 20~24 years, 1.451 (1.410~ 1.494) in 25~29 years, 1.193 (1.149~1.238) in 30~34 years, 1.068 (0.996~1.146) in 35~39 years and 1.096 (0.939~1.280) in 40 years and older. Compared with PTB rate of women aged 25~29 years in phase I and phase II, respectively, a slightly decrease in adjusted odds ratios among women aged 30~34 was found for PTB rate (1.542 versus 1.171), for women aged 35~39 (2.230 versus 1.567) and for women aged 40 years and older (2.731 versus 1.923).
Conclusions Rate of PTB between phase I & II increased higher in primiprous women aged 20~ 29 years, whereas rates remained stable in women aged 35~39, and 40 years and older. There was a need to understand the contributing maternal age factors to PTB, and to reduce PTB rate for women aged 20~29 years. |
Key Words:
preterm, maternal age, primiparous women |
|