Risk factors for preterm birth: a prospective cohort study

Zhongguo Dang Dai Er Ke Za Zhi. 2021 Dec 15;23(12):1242-1249. doi: 10.7499/j.issn.1008-8830.2108015.
[Article in English, Chinese]


Objectives: To investigate the incidence of preterm birth and risk factors for preterm birth.

Methods: A prospective cohort study was performed for the pregnant women in early pregnancy and their spouses, who underwent prenatal examination for the first time in Hunan Provincial Maternal and Child Health Care Hospital from May 2014 to December 2016 and decided to be hospitalized for delivery. A questionnaire survey was performed to collect exposure information possibly related to preterm birth. The hospital's medical record system was used for information verification and to record the pregnancy outcome. A multivariate logistic regression analysis was used to investigate the risk factors for preterm birth.

Results: A total of 6 764 pregnant women with complete data were included, and the incidence rate of preterm birth was 17.09%. The multivariate logistic regression analysis showed that a history of adverse pregnancy outcomes, eating areca nut before pregnancy, a history of pregnancy complications, a history of hepatitis, no folate supplementation during pregnancy, medication during pregnancy, active smoking and passive smoking during pregnancy, drinking during pregnancy, unbalanced diet during pregnancy, high-intensity physical activity during pregnancy, and natural conception after treatment of infertility or assisted conception as the way of conception were risk factors for preterm birth (P<0.05). Additionally, the pregnant women whose spouses were older, had a higher body mass index or smoked had an increased risk for preterm birth (P<0.05). A higher level of education of pregnant women or their spouses and lower gravidity were protective factors against preterm birth (P<0.05).

Conclusions: There are many risk factors for preterm birth. Special attention should be paid to the life behaviors of pregnant women during pregnancy, and health education should be strengthened for pregnant women and their spouses to develop good living habits and reduce the incidence of preterm births.

目的: 了解早产的发生情况,并探讨早产发生的危险因素。方法: 以2014年5月至2016年12月在湖南省妇幼保健院首次参加产前检查并决定住院分娩的孕早期孕妇及其配偶为研究对象开展前瞻性队列研究。采用调查问卷收集可能与早产发生相关的暴露信息,并通过医院病历系统完成信息核查,记录妊娠结局。采用多因素logistic回归分析探讨早产发生的危险因素。结果: 共收集6 764例孕妇完整资料,其早产发生率为17.09%。多因素logistic回归分析显示,孕妇有不良妊娠史、孕前进食槟榔、有妊娠并发症史、有肝炎史、孕期未补充叶酸、孕期服药、孕期主动/被动吸烟、孕期饮酒、孕期不均衡饮食、孕期强体力活动、受孕方式为不孕经治疗自然受孕和辅助受孕,以及配偶年龄较大、体重指数较高、吸烟均为早产发生的危险因素(P<0.05);而孕妇教育水平高、配偶教育水平高、孕次少是早产发生的保护因素(P<0.05)。结论: 早产的危险因素很多,应特别注重孕妇的孕期生活行为,对孕妇及其配偶加强卫生宣教,养成良好的生活习惯,以减少早产的发生。.

Keywords: Pregnant woman; Preterm birth; Prospective cohort study; Risk factor.

MeSH terms

  • Child
  • Female
  • Humans
  • Infant, Newborn
  • Pregnancy
  • Pregnancy Outcome
  • Premature Birth* / epidemiology
  • Premature Birth* / etiology
  • Prospective Studies
  • Risk Factors
  • Tobacco Smoke Pollution*


  • Tobacco Smoke Pollution