Increase in Preterm Birth during Demographic Transition in Chile from 1991 to 2012.

Paulina López Orellana

doi:10.1155/2015/845968

Abstract

Introduction. Universally mothers at 35 years or more have had higher maternal and perinatal risks. This study analyzed the trend of this group in maternal population and determined their risk of having premature children, during the demographic transition period in Chile. Materials and Methods. Epidemiological study conducted in the population of simple live births registered in the Chilean National Database Births of 1991–2012. Analyses were performed in three categories of maternal age: 35 or more, under 35, and 20 to 29 years. The risk of prematurity was measured by crude and Adjusted Odds Ratio from logistic regression model. Results. Mothers aged 35 and older increased in population from 10.6% in 1991 to 16.7% in 2012 and presented an overall prevalence of preterm delivery of 6.7%, higher prevalence than 20–29 age group (4.7%). In aging mothers, the Odds Ratio for preterm birth adjusted for education, marital status, and parity was 1.68 (95% CI (1.66–1.70)) compared to mothers aged 20–29. All differences were significant (p < 0.001). Conclusions. During Chilean demographic transition, mothers aged 35 or older increased steadily and significantly maintaining higher risks of preterm births. Policies to prevent and monitor the late motherhood could contribute to stopping the current trend.

Highlights

Mothers at 35 years or more have had higher maternal and perinatal risks
The present study provided information to evaluate emerging problem of maternal and perinatal health, a public health problem as part of changes in population in demographic transition period [17]
Chile was completing the demographic transition and countries that have already done so, like Norway, reached one-third of maternal population older than 34, close to ratios which were observed in Central Europe

Summary

Introduction

Mothers at 35 years or more have had higher maternal and perinatal risks. During Chilean demographic transition, mothers aged 35 or older increased steadily and significantly maintaining higher risks of preterm births. In Chile, the demographic and health statistics indicated changes that were expressed in a decrease in the birth rate and fertility, the latest age at first birth, and other modifications of socioeconomic order such as increased schooling and the female employment rate. These changes resulted from the demographic and epidemiological transition that was occurring since the 80s; in this context, increasing of maternal age corresponded to the demographic structure of population aging [4, 5]. 51% of maternal deaths that occurred between 2000 and 2009 were associated with comorbidities that mostly affect mothers over 35 years [6,7,8]

Methods

Results

Conclusion