Racial/ethnic disparities and human milk use in necrotizing enterocolitis.

BACKGROUND: The impact of human milk use on racial/ethnic disparities in necrotizing enterocolitis (NEC) incidence is unknown. METHODS: Trends in NEC incidence and human milk use at discharge were evaluated by race/ethnicity among 47,112 very low birth weight infants born in California from 2008 to 2017. We interrogated the association between race/ethnicity and NEC using multilevel regression analysis, and evaluated the effect of human milk use at discharge on the relationship between race/ethnicity and NEC using mediation analysis. RESULTS: Annual NEC incidence declined across all racial/ethnic groups from an aggregate average of 4.8% in 2008 to 2.6% in 2017. Human milk use at discharge increased over the time period across all racial groups, and non-Hispanic (NH) black infants received the least human milk each year. In multivariable analyses, Hispanic ethnicity (odds ratio (OR) 1.27, 95% confidence interval (CI) 1.02-1.57) and Asian or Pacific Islander race (OR 1.35, 95% CI 1.01-1.80) were each associated with higher odds of NEC, while the association of NH black race with NEC was attenuated after adding human milk use at discharge to the model. Mediation analysis revealed that human milk use at discharge accounted for 22% of the total risk of NEC in non-white vs. white infants, and 44% in black vs. white infants. CONCLUSIONS: Although NEC incidence has declined substantially over the past decade, a sizable racial/ethnic disparity persists. Quality improvement initiatives augmenting human milk use may further reduce the incidence of NEC in vulnerable populations.

Association of Race/Ethnicity With Very Preterm Neonatal Morbidities.

Importance: Severe morbidity in very preterm infants is associated with profound clinical implications on development and life-course health. However, studies of racial/ethnic disparities in severe neonatal morbidities are scant and suggest that these disparities are modest or null, which may be an underestimation resulting from the analytic approach used. Objective: To estimate racial/ethnic differences in severe morbidities among very preterm infants. Design, Setting, and Participants: This population-based retrospective cohort study was conducted in New York City, New York, using linked birth certificate, mortality data, and hospital discharge data from January 1, 2010, through December 31, 2014. Infants born before 24 weeks' gestation, with congenital anomalies, and with missing data were excluded. Racial/ethnic disparities in very preterm birth morbidities were estimated through 2 approaches, conventional analysis and fetuses-at-risk analysis. The conventional analysis used log-binomial regression to estimate the relative risk of 4 severe neonatal morbidities for the racial/ethnic groups. For the fetuses-at-risk analysis, Cox proportional hazards regression with death as competing risk was used to estimate subhazard ratios associating race/ethnicity with each outcome. Estimates were adjusted for sociodemographic factors and maternal morbidities. Data were analyzed from September 5, 2017, to May 21, 2018. Main Outcomes and Measures: Four morbidity outcomes were defined using International Classification of Diseases, Ninth Revision, diagnosis and procedure codes: necrotizing enterocolitis, intraventricular hemorrhage, bronchopulmonary dysplasia, and retinopathy of prematurity. Results: In total, 582 297 infants were included in this study. Of these infants, 285 006 were female (48.9%) and 297 291 were male (51.0%). Using the conventional approach in the very preterm birth subcohort, black compared with white infants had an increased risk of only bronchopulmonary dysplasia (adjusted risk ratio [aRR], 1.34; 95% CI, 1.09-1.64) and a borderline increased risk of necrotizing enterocolitis (aRR, 1.39; 95% CI, 1.00-1.93). Hispanic infants had a borderline increased risk of necrotizing enterocolitis (aRR, 1.39; 95% CI, 0.98-1.96), and Asian infants had an increased risk of retinopathy of prematurity (aRR, 1.85; 95% CI, 1.15-2.97). In the fetuses-at-risk analysis, black infants had a 4.40 times higher rate of necrotizing enterocolitis (95% CI, 2.98-6.51), a 2.73 times higher rate of intraventricular hemorrhage (95% CI, 1.63-4.57), a 4.43 times higher rate of bronchopulmonary dysplasia (95% CI, 2.88-6.81), and a 2.98 times higher rate of retinopathy of prematurity (95% CI, 2.01-4.40). Hispanic infants had an approximately 2 times higher rate for all outcomes, and Asian infants had increased risk only for retinopathy of prematurity (adjusted hazard ratio, 2.43; 95% CI, 1.43-4.11). Conclusions and Relevance: In this study, racial/ethnic disparities in neonatal morbidities among very preterm infants appear to be sizable, but may have been underestimated in previous studies, and may have implications for the future. Understanding these racial/ethnic disparities is important, as they may contribute to inequalities in health and development later in the child's life.

Racial/ethnic differences in necrotizing enterocolitis incidence and outcomes in premature very low birth weight infants.

BACKGROUND: As advances in neonatal intensive care increase the survival of extremely premature infants, the at-risk population for necrotizing enterocolitis (NEC) continues to rise. Although racial health disparities in preterm births have been well documented, large-scale studies exploring racial differences in NEC outcomes are lacking. Here, we conduct a study of racial health disparities in NEC using a nationally representative multicenter cohort. STUDY DESIGN: Infants ≤1500 g birth weight and ≤30 weeks gestational age admitted in the first week after birth to neonatal intensive care units in the Pediatrix Medical group from 1997 to 2015 were included. Multivariable logistic regression was used to determine the adjusted odds ratio (AOR) of risk factors related to NEC and associated mortality. RESULTS: Of the 126,089 (45% non-Hispanic White, 27% non-Hispanic Black, and 19% Hispanic) infants who met the inclusion criteria, 8796 (7%) developed NEC. On multivariable analysis, non-Hispanic Black and Hispanic infants had higher odds of developing NEC (AOR 1.31, 95% confidence interval (CI) [1.24-1.39], p < 0.001 and AOR 1.30 [1.21-1.39], p < 0.001, respectively). Among infants with NEC, mortality was higher in non-Hispanic Black and Hispanic infants compared to non-Hispanic White infants (AOR 1.35 [1.15-1.58], p < 0.001 and AOR 1.31 [1.09-1.56], p = 0.003, respectively). CONCLUSION: Our study demonstrates that non-Hispanic Black and Hispanic infants are significantly more likely to be diagnosed with NEC. In addition, non-Hispanic Black and Hispanic infants have higher odds of death after NEC compared to non-Hispanic White infants. Further studies are necessary to investigate the etiology of these health disparities and to test interventions to improve these health outcomes.

Infant and maternal risk factors related to necrotising enterocolitis-associated infant death in the United States.

AIM: To evaluate necrotising enterocolitis (NEC)-associated infant death and identify risk factors related to NEC infant death in the United States. METHODS: The United States Period Linked Birth/Infant Death data for 2010-2013 were utilised to determine risk factors associated with NEC infant death. Infant mortality rates (IMRs) were calculated and a retrospective matched case-control analysis was performed. An infant case was defined as having the International Classification of Diseases, Tenth Revision code for NEC listed on the death record. Controls were matched on birthweight and randomly selected. Conditional multivariable logistic regression models stratified by birthweight were conducted to determine risk factors for NEC infant death. RESULTS: The average annual NEC IMR was 12.5 deaths per 100 000 live births and was higher among very low birthweight (VLBW) compared to normal birthweight infants and among black compared to white infants. For VLBW infants, the multivariable analysis identified male sex, five-minute Apgar score of less than 7, and white infants born to a mother who is less than or equal to 19 years of age to be related with NEC-associated infant death. CONCLUSION: Paediatricians should be aware of the factors related to NEC-associated infant death to reduce the number of infants at greatest risk for NEC and focus on racial disparities.

Epidemiology of neonatal necrotising enterocolitis: a population-based study.

We examined the birthweight-, gender- and race-specific incidence as well as the biodemographic and clinical correlates of necrotising enterocolitis (NEC) in a well-defined six-county perinatal region in upstate New York. We conducted a retrospective, 8-year population-based survey to identify all cases of proven NEC (modified Bell stage II and above) in the area's regional neonatal intensive care unit (NICU). The denominator used to calculate the incidence was obtained from the Statewide Planning Research Cooperative System. Incidence was expressed as cases per 1000 live births. A total of 85 documented cases of proven NEC was identified in a six-county perinatal region that experienced 117 892 live births during the 8-year period. The average annual incidence was 0.72 cases per 1000 live births [95% CI 0.57, 0.87 per 1000 live births]. The highest incidence of NEC occurred among infants weighing 750-1000 g at birth and declined with increasing birthweight. The urban county had a 1.53 times higher risk of NEC than rural counties [95% CI 0.9, 2.6]. The overall incidence of NEC for non-Hispanic blacks was significantly greater than that for non- Hispanic whites (2.2 vs. 0.5 cases per 1000 live births, P = 0.00). The differences remained statistically significant even after correction for birthweight. Most cases (93%) in this series were preterm (gestational age <37 weeks). Only two patients were never fed before the diagnosis of NEC was confirmed. Positive blood cultures were documented in 27% of the cases with a predominance of Gram-negative enteric micro-organisms. NEC remains an important health problem especially for preterm infants and the non-Hispanic black population.

Comparison of clinical characteristics and high-risk factors in Australian aboriginal and non-aboriginal neonates with necrotising enterocolitis.

In a five-year retrospective data analysis, incidence of > stage II necrotising enterocolitis (NEC) was four times higher in aboriginal (18/125) than non-aboriginal (11/306) neonates, all < or = 32 weeks' gestation. Stage III NEC occurred more frequently (10/18 vs 3/11) and related mortality was higher (44.4% vs 0%) in aboriginal than non-aboriginal neonates. Risk factors for NEC-prolonged rupture of membranes (50% vs 9.1%, p = 0.01), prematurity (median [range] gestational age: 25 (24-28.5) vs 30 [27-33]) weeks, p = 0.02), birth weight (< 1 kg 13 [72%] vs 2 [18%], p = 0.007) and intrauterine growth retardation (50% vs 0%, p = 0.01) occurred more frequently in aboriginal neonates. Though feed type and increments per day were similar, aboriginal neonates received higher volume of feeds/kg/day (median [range]: 154 [145-189] vs 106 [103-134] ml, p < 0.05). Condition at delivery and respiratory status before development of NEC were not significantly different.