[Literature Library] Risk factors for preterm birth

Preterm birth (<37 weeks of gestation) is a major cause of perinatal morbidity and mortality. A population-based retrospective cohort study analyzing 334,415 deliveries has examined the influences of various risk factors for extremely preterm birth (24-28 weeks of gestation) and if these changed between different sub-populations with known risk factors.

• Strongest risk factors for extremely preterm birth were:
  • Placental abruption (OR = 20.606, 95%CI 17.006-24.969, p < 0.001)
  • Multi-gestations (OR = 7.714, 95%CI 6.581-9.042, p < 0.001)
  • Placenta previa (OR = 5.884, 95%CI 4.149-8.344, p < 0.001)
     
• Risk factors for singleton extremely preterm birth included:
  • Placental abruption (OR = 24.619, 95%CI 20.063-30.210, p < 0.001)
  • Placenta previa (OR = 5.845, 95%CI 4.022-8.945, p < 0.001))
  • Previous preterm birth (OR = 2.305, 95%CI 1.980-2.784, p < 0.001)
  • Nulliparity (OR = 2.226, 95%CI 1.902-2.605, p < 0.001)
  • Lack of prenatal care (OR = 2.136, 95%CI 1.772-2.574, p < 0.001)
     
• Among all groups, placental abruption was the strongest risk factor for extremely preterm birth whereas no significant difference on risk factors between sub-populations was observed