Racial and ethnic disparities in postnatal growth among very low birth weight infants in California

Objective: To identify racial/ethnic disparities in postnatal growth by year and gestational age among very low birth weight (VLBW) infants. Study design: Retrospective cohort of 37,122 infants with birth weight 500–1500 g or gestational age 23–34 weeks cared for in the California Perinatal Quality Care Collaborative (2008–2016). Postnatal growth failure (PGF) was defined as a change in weight Z-score from birth to discharge below −1.28 (Fenton growth charts). Multivariable regression with birth hospital as a random effect estimated odds ratios (OR). Results: Infants of Hispanic mothers had the highest risk of PGF (30%) compared with infants of white (24%; OR 1.33), Black (22%; OR 1.50), or Asian/Pacific Islander (23%; OR 1.38) mothers. PGF incidence decreased from 27.4% in 2008 to 22.8% in 2016, with differences in trends by race/ethnicity. Each additional gestational age week was associated with lower PGF risk (OR 0.73, 95% CI 0.72–0.74). Conclusion: Racial/ethnic disparities in PGF persist; targeted interventions addressing PGF are needed to mitigate disparities.