Secular variation and risk factors of preterm birth in Hainan, The Free Trade Port in China from 2010 to 2021

Abstract

Abstract Objectives Preterm delivery rates have increased obviously worldwide over the past decade, yet reliable epidemiological studies on the incidence of preterm birth and temporal trends are not available in Hainan, The Free Trade Port in China. We aimed to describe the rate of preterm birth and trends between 2010 and 2021 and to primarily explore risk factors associated with preterm birth in Hainan, China. Methods This was an observational study was based on data from the Hainan Provincial Birth Certificate System (HPBCS) for live births between 1 January 2010 and 31 December 2021.Pregnancies with at least one live birth, with the baby born at 28 weeks of gestation or more or 1000 g or more birthweight were included.The outcome were preterm birth rates and their trends over time. Potential risk factors were collected, including infant’s date of birth, infant gender, maternal age, paternal age, maternal ethnicity, paternal ethnicity, gestational age at delivery, mode of delivery, and single or multiple pregnancies. The logistic regression model was used to assess the relationship between preterm birth and potential risk factors. Results A total of 1,537,239 live births and 86,328 preterm births were investigated, giving a total preterm birth rate of 5.6%. The overall preterm birth rate increased from 5.62% in 2010 to 7.1% in 2021 (compound annual growth rate [CAGR] 4.3). The CAGR of late preterm birth is consistent with the overall preterm birth rate (4.3%). The fastest growth is observed in the rate of early preterm births (5.5%), while the rate of mid-term preterm births exhibits the slowest growth (3.9%). Infant gender, multiple pregnancy, parental age, and ethnicity had significant effects on preterm birth. Conclusion The preterm birth rate was increasing year by year from 2010 to 2021 in Hainan, The Free Trade Port in China. Multiple pregnancies, higher maternal age at delivery, and male infants were associated with a higher rate of preterm birth.