BACKGROUND AND PURPOSE:

• Up to one third of all infants < 28 weeks will have intraventricular hemorrhage (IVH)
• Yeo et al. (Archives of Disease in Childhood – Fetal and Neonatal Edition, 2019) examined the trend and risk factors for IVH among infants <32 weeks gestation)

METHODS:

• Population-based cohort study (1995 to 2012)
  • Australian and New Zealand Neonatal Network (ANZNN)
• Participants
  • All preterm infants born <32 weeks gestation
• Interventions
  • Comparison of incidence of IVH between 6-year epochs
  • 6-year epochs: Epoch 1: 1995 to 2000 | Epoch 2: 2001 to 2006 | Epoch 3: 2007 to 2012
• Primary outcomes
  • Overall IVH and severe IVH incidence (Grade 3 and 4)
• Secondary outcome
  • Combined outcome of severe IVH and/or death over time

RESULTS:

• 60,068 infants
  • Overall survival to discharge increased over the three epochs from 89% to 93%
  • Increase seen in: Antenatal steroid usage | Increase in caesarean-section births
  • Decrease seen in: Infant intubation at birth | Low 5 min Apgar score | Sepsis
• The percentage of infants with IVH decreased over the three epochs (p<0.001)
  • Epoch 1: 23.6%
  • Epoch 2: 21.3%
  • Epoch 3: 21.4%
• Fewer surviving infants had severe IVH over time (p<0.001)
  • Epoch 1: 4.0%
  • Epoch 2: 3.3%
  • Epoch 3: 2.8%
• There was significant reduction risk for severe IVH from epoch 1 to 3 when adjusting for perinatal confounders
  • Adjusted odds ratio (AOR) 0.8 (95% CI, 0.7 to 0.9)
• Factors associated with development of severe IVH include
  • No antenatal steroids: AOR 1.7 (95% CI, 1.5 to 1.9)
  • Male infant: AOR 1.3 (95% CI, 1.2 to 1.4)
  • 5 min Apgar score <7: AOR 2.0 (95% CI, 1.9 to 2.2)
  • Intubated at birth: AOR 2.0 (95% CI, 1.8 to 2.2)
  • Extremely low gestational age: AOR 4.0 (95% CI, 3.7 to 4.4)
  • Outborn (born in outside centers and transported in to main center): AOR 1.6 (95% CI, 1.5 to 1.8)
  • Vaginal delivery: AOR 1.4 (95% CI, 1.3 to 1.6)
• Study found protective effect related to preeclampsia

CONCLUSION:

• Over time, more infants born <32 weeks gestation were surviving and incidence of severe IVH decreased
• Decrease in IVH incidence may be related to reduced risk factor rates over the same time period
  • Use of antenatal steroids
  • Switch from intubation at birth to nasal CPAP
• Authors note that factors are associated but do not necessarily cause severe IVH
• Study confirms previous studies that preeclampsia may be protective for IVH and authors postulate
  • Angiogenic factors may play a role
  • Medications may impact rate of IVH

Learn More – Primary Sources:

Improving incidence trends of severe intraventricular haemorrhages in preterm infants <32 weeks gestation: a cohort study

Related ObG Topics:

Cesarean or Vaginal Delivery for Extremely Preterm Breech Singletons Less Than 28 Weeks?

Antenatal Corticosteroids – When to Administer?

Do Antenatal Corticosteroids Reduce Morbidity in Premature Neonates Prior to 24 weeks?

17-OHPC Treatment and Prevention of Preterm Birth: Does Timing Matter?