Association of a Count of Inpatient Morbidities with 2-Year Outcomes among Infants Born Extremely Preterm

Objective: To determine if number of neonatal morbidities is associated with death or severe neurodevelopmental impairment (sNDI) among infants born extremely preterm who survived to 36 weeks' postmenstrual age (PMA).

Study design: This is a retrospective cohort analysis of prospectively collected data from 15 NICHD Neonatal Research Network centers. Neonatal morbidities and 2-year outcomes were examined for 3794 infants born at 22 to 26 weeks' gestation from 2014 through 2019 who survived to 36 weeks' PMA.

Results: Serious brain injury (SBI), bronchopulmonary dysplasia (BPD), and severe retinopathy of prematurity (ROP) had the strongest bivariate associations with death or sNDI (ORs, 95% CI): 3.96 (3.39, 4.64), 3.41 (2.94, 3.95), and 2.66 (2.28, 3.11)], respectively. A morbidity count variable was constructed using these morbidities. The estimated ORs and 95% CI for death or sNDI with any 1, any 2, or all 3 of these morbidities, adjusted for maternal and infant characteristics and hospital of birth, increased from 2.75 (2.25, 3.37) to 6.10 (4.83, 7.70) to 12.90 (9.07, 18.36), respectively. Corresponding rates of late death or sNDI with none, any 1, any 2, and all 3 morbidities were 12.6%, 30.3%, 51.9%, and 69.9%, respectively. The estimated logistic model produced predictions of death or sNDI with moderate discrimination (C-statistic [95% CI]: 0.765 [0.749, 0.782]) and good calibration (Intercept [CITL] = -0.004, slope = 1.026).

Conclusions: Among infants born extremely preterm who survived to 36 weeks' PMA, a count of SBI, BPD, and severe ROP predicts death or sNDI.

Trial registration: ClinicalTrials.gov ID Generic Database: NCT00063063.