Leading causes of preterm delivery as risk factors for intraventricular hemorrhage in very preterm infants: results of the EPIPAGE 2 cohort study

Background Intraventricular hemorrhage is a major risk factor for neurodevelopmental disabilities in preterm infants. However, few studies have investigated how pregnancy complications responsible for preterm delivery are related to intraventricular hemorrhage. Objective We sought to investigate the association between the main causes of preterm delivery and intraventricular hemorrhage in very preterm infants born in France during 2011 between 22-31 weeks of gestation. Study Design The study included 3495 preterm infants from the national EPIPAGE 2 cohort study who were admitted to neonatal intensive care units and had at least 1 cranial ultrasound assessment. The primary outcome was grade I-IV intraventricular hemorrhage according to the Papile classification. Multinomial logistic regression models were used to study the relationship between risk of intraventricular hemorrhage and the leading causes of preterm delivery: vascular placental diseases, isolated intrauterine growth retardation, placental abruption, preterm labor, and premature rupture of membranes, with or without associated maternal inflammatory syndrome. Results The overall frequency of grade IV, III, II, and I intraventricular hemorrhage was 3.8% (95% confidence interval, 3.2–4.5), 3.3% (95% confidence interval, 2.7–3.9), 12.1% (95% confidence interval, 11.0–13.3), and 17.0% (95% confidence interval, 15.7–18.4), respectively. After adjustment for gestational age, antenatal magnesium sulfate therapy, level of care in the maternity unit, antenatal corticosteroids, and chest compressions, infants born after placental abruption had a higher risk of grade IV and III intraventricular hemorrhage compared to those born under placental vascular disease conditions, with adjusted odds ratios of 4.3 (95% confidence interval, 1.1–17.0) and 4.4 (95% confidence interval, 1.1–17.6), respectively. Similarly, preterm labor with concurrent inflammatory syndrome was associated with an increased risk of grade IV intraventricular hemorrhage (adjusted odds ratio, 3.4; 95% confidence interval, 1.1–10.2]). Premature rupture of membranes did not significantly increase the risk. Conclusion Relationships between the causes of preterm birth and intraventricular hemorrhage were limited to specific and rare cases involving acute hypoxia-ischemia and/or inflammation. While the emergent nature of placental abruption would challenge any attempts to optimize management, the prenatal care offered during preterm labor could be improved.