Preterm birth trend in Taiwan from 2001 to 2009

Abstract

Aim: The aim of this study was to analyze the trends and risk factors of preterm birth from all the women who delivered during 2001-2009 in Taiwan.

Material and methods: We analyzed the preterm birth rates, the proportions of obstetric antecedents and risk factors in the population of pregnant women and neonatal Apgar scores according to the National Medical Birth Register database from 2001 to 2009. Adjusted odds ratios (OR) with 95% confidence intervals for risk factors of preterm birth were assessed using multivariable logistic regression models. The obstetric antecedents of preterm birth for singletons were stratified by spontaneous preterm labor and indicated preterm delivery (labor induction or elective cesarean delivery).

Results: The preterm birth rate was 8.56% with the majority (89.76%) delivered between 32 and 37 weeks of gestation. A 0.07% annual increase (P < 0.001) in preterm delivery was observed. The greatest risk factors were multiple pregnancies (OR > 20), followed by medical complications (OR > 2.8), congenital malformations (OR > 2), teen pregnancies (OR > 1), and advanced maternal age (OR > 1). Specifically, singleton preterm births comprised 57.3% spontaneous labor and 42.7% indicated delivery. There was a 0.5% annual increase (P < 0.001) in indicated delivery. Incidence of neonates with poor Apgar scores (<7) was significantly different between those with and without medical complications (P < 0.001).

Conclusions: The preterm birth rate increased significantly from 2001 to 2009 and multiple pregnancies were the most important contributing factor. Most of the singleton preterm births resulted from spontaneous labor, but the proportion of indicated deliveries increased.

Keywords: induced preterm delivery; neonatal outcome; preterm birth; spontaneous preterm labor.