Purpose of review Over 300 000 infants are hospitalized in a neonatal intensive care unit (NICU) in the United States annually during a developmental period critical to later neurobehavioral function. Environmental exposures during the fetal period and infancy have been shown to impact long-term neurobehavioral outcomes. This review summarizes evidence linking NICU-based environmental exposures to neurodevelopmental outcomes of children born preterm. Recent findings Preterm infants experience multiple exposures important to neurodevelopment during the NICU hospitalization. The physical layout of the NICU, management of light and sound, social interactions with parents and NICU staff, and chemical exposures via medical equipment are important to long-term neurobehavioral outcomes in this highly vulnerable population. Summary Existing research documents NICU-based exposure to neurotoxic chemicals, aberrant light, excess sound, and restricted social interaction. In total, this creates an environment of co-existing excesses (chemicals, light, sound) and deprivation (touch, speech). The full impact of these co-exposures on the long-term neurodevelopment of preterm infants has not been adequately elucidated. Research into the importance of the NICU from an environmental health perspective is in its infancy, but could provide understanding about critical modifiable factors impacting the neurobehavioral health of hundreds of thousands of children each year.

OBJECTIVE: To determine the trends in incidence of diagnosis of bronchopulmonary dysplasia (BPD) and associated health services use for the neonatal hospitalization of patients with BPD in an era of changing definitions and management. PATIENTS AND METHODS: All neonatal hospitalization records available through the Nationwide Inpatient Sample, 1993–2006, were analyzed. Multivariable regression analyses were performed for incidence of BPD diagnosis and associated hospital length of stay and charges. Multiple models were constructed to assess the roles of changes in diagnosis of very low birth weight (VLBW) neonates and different modalities of respiratory support used for treatment. RESULTS: The absolute incidence of diagnosis of BPD fell 3.3% annually (P = .0009) between 1993 and 2006 coincident with a 3.5-fold increase in the use of noninvasive respiratory support in patients with BPD. When data were controlled for demographic factors, this significant decrease in incidence persisted at a rate of 4.3% annually (P = .0002). All models demonstrated a rise in hospital length of stay and financial charges for the neonatal hospitalization of patients with BPD. The incidence of BPD adjusted for frequency of prolonged mechanical ventilation also decreased but only by 2.8% annually (P = .0075). CONCLUSIONS: The incidence of diagnosis of BPD decreased significantly between 1993 and 2006. In well-controlled models, birth hospitalization charges for these patients rose during the same period. Less invasive ventilatory support may improve respiratory outcomes of VLBW neonates.

Every year in the United States, more than 300,000 infants are admitted to neonatal intensive care units (NICU) where they are exposed to a chemical-intensive hospital environment during a developmentally vulnerable period. The neurodevelopmental impact of environmental exposure to phthalates during the NICU stay is unknown. As phthalate exposure during the third trimester developmental window has been implicated in neurobehavioral deficits in term-born children that are strikingly similar to a phenotype of neurobehavioral morbidity common among children born premature, the role of early-life phthalate exposure on the neurodevelopmental trajectory of premature infants may be clinically important. In this study, premature newborns with birth weight <1500g were recruited to participate in a prospective environmental health cohort study, NICU-HEALTH (Hospital Exposures and Long-Term Health), part of the DINE (Developmental Impact of NICU Exposures) cohort of the ECHO (Environmental influences on Child Health Outcomes) program. Seventy-six percent of eligible infants enrolled in the study. Sixty-four of 81 infants survived and are included in this analysis. 164 urine specimens were analyzed for phthalate metabolites using high-performance liquid chromatography/tandem mass spectrometry. The NICU Network Neurobehavioral Scale (NNNS) was performed prior to NICU discharge. Linear and weighted quantile sum regression quantified associations between phthalate biomarkers and NNNS performance, and between phthalate biomarkers and intensity of medical intervention. The sum of di(2-ethylhexyl) phthalate metabolites (∑DEHP) was associated with improved performance on the Attention and Regulation scales. Specific mixtures of phthalate biomarkers were also associated with improved NNNS performance. More intense medical intervention was associated with higher ∑DEHP exposure. NICU-based exposure to phthalates mixtures was associated with improved attention and social response. This suggests that the impact of phthalate exposure on neurodevelopment may follow a non-linear trajectory, perhaps accelerating the development of certain neural networks. The long-term neurodevelopmental impact of NICU-based phthalate exposure needs to be evaluated.