The Clinical Burden of Extremely Preterm Birth: Findings from a Large Medical Records Database in the United States

Introduction Infants born extremely preterm (EP; <28 weeks’ gestational age [wGA]) are at high risk for mortality and for developing complications, including bronchopulmonary dysplasia (BPD), respiratory complications, intraventricular hemorrhage (IVH), and retinopathy of prematurity (ROP). We utilized the electronic medical records database of Kaiser Permanente Northern California to evaluate the clinical burden of EP birth in terms of mortality, complications of prematurity, and healthcare resource utilization.

Materials and Methods EP infants with live births between January 1997 and December 2016 were included. Infants with major congenital malformations, and those born <22 wGA, were excluded. Outcomes included incidence of complications associated with EP births (BPD, respiratory complications, IVH, and ROP) identified during birth hospitalization and/or up to 3 years of age; mortality rates up to 2 years of age; respiratory medication use up to 2 years of age; and hospital readmissions, outpatients’ and emergency room (ER) visits for respiratory complications up to 3 years of age. International Classification of Diseases, Ninth/Tenth Revision, Clinical Modification (ICD-9-CM/ICD-10-CM) codes were used to identify complications.

Results Among 704,989 live births, a total of 2,154 (0.31%) eligible infants met the study definition of EP (representing 4.0% of infants born preterm); of these infants, 52.6% were male and 76.6% were singletons. The cumulative mortality rate among EP infants was 42.5% at 1 to 2 years of age. BPD was present in 34.3% of EP infants during birth hospitalization, IVH in 22.7%, and ROP in 37.1%. The proportion of children born EP and diagnosed with respiratory complications was 78.7% (1,695/2,154) from birth to 1 year of age, 59.7% (740/1,240) between 1 and 2 years, and 46.0% (570/1,239) between 2 and 3 years. Medication use for respiratory complications among children born EP was 35.3%, 41.2 and 36.0% at <1 year CA, 1 year CA, and 2 years CA, respectively. The proportion of children born EP with a hospital readmission (3-year follow-up) was 16.4%. Overall, 28.5 and 53.9% of EP infants had ≥2 ER and outpatients visits, respectively.

Conclusion The short-term and long-term clinical burden among children born EP birth is high.

Conflict of Interest

None declared.