INSERM, UMR S953, Recherche épidémiologique en santé périnatale et santé des femmes et des enfants, Hôpital Tenon, Paris F-75020, France.
Reprod Health. 2013 May 16;10:26. doi: 10.1186/1742-4755-10-26.
Preterm birth is a global problem in Perinatal and infant Health. Currently is gaining a growing attention. Rates of preterm birth have increased in most countries, producing a dramatic impact on public health. Factors of diverse nature have been associated to these trends. In Chile, preterm birth has increased since 90. Simultaneously, the advanced demographic transition has modified the characteristics of woman population related to maternity. The principal objective of this study is to analyze some sociodemographic characteristics of the maternal population over time, and their possible association to rates of preterm birth. The second aim is to identify groups of mothers at high risk of having a preterm child.
This population-based study examined all liveborn singletons in Chile from 1991 to 2008; divided in three periods. Preterm birth rates were measured as % births <37 weeks of gestation. Logistic regression assessed the risk of preterm birth associated with mother's age, parity, and marital status, expressed as crude and adjusted odds ratios.
Over time, rates of preterm birth increased in overall population, especially during the third period (2001-2008). In the same time, characteristics of maternal population changed: significant increase of extreme reproductive ages, significant decrease in parity and increase in mothers living without a partner. Risk of preterm birth remained higher in groups of mothers: <18 and >38 years of age; without a partner; primiparas and grandmultiparas. However, global increase in preterm birth was not explained by the modification of socio demographics characteristics of maternal population.
Some socio demographic characteristics remained associated with preterm birth over time. These associations allowed identifying five groups of mothers at higher risk to have a preterm child in the population. Increase in overall preterm birth affected all women, even those considered at "low sociodemographic risk" and the contribution of more recent period (2001-2008) to this increase is greater. Then, studied factors couldn't explain the increase in preterm birth. Further research will have to consider other factors affecting maternal population that could explain the observed trend of preterm birth.
早产是围产儿和婴儿健康方面的一个全球性问题。目前，早产问题越来越受到关注。大多数国家的早产率都有所上升，这对公共卫生产生了巨大影响。各种性质的因素都与这些趋势有关。在智利，自 90 年代以来，早产率有所上升。与此同时，人口的快速转变改变了与生育有关的女性人口特征。本研究的主要目的是分析一段时间内产妇人群的一些社会人口学特征，及其与早产率的可能关联。第二个目的是确定早产高危产妇群体。
本基于人群的研究调查了智利 1991 年至 2008 年期间所有活产单胎；分为三个时期。早产率以<37 周妊娠的出生百分比表示。采用 logistic 回归评估母亲年龄、产次和婚姻状况与早产风险的关系，以粗比和调整比值比表示。
随着时间的推移，总体人群的早产率增加，尤其是在第三时期（2001-2008 年）。同时，产妇人群的特征发生了变化：极龄产妇显著增加，产次显著减少，无伴侣的产妇增加。然而，早产风险的增加不能用产妇人群社会人口特征的改变来解释。
随着时间的推移，一些社会人口特征仍然与早产有关。这些关联可以确定五个高危产妇群体，这些群体在人群中更有可能生育早产儿。总体早产率的增加影响了所有妇女，即使是那些被认为处于“低社会人口风险”的妇女，而且最近时期（2001-2008 年）对这一增加的贡献更大。因此，研究中的因素并不能解释早产率的增加。进一步的研究将不得不考虑影响产妇人群的其他因素，这些因素可以解释观察到的早产趋势。
