(281) Neonatal Intensive Care Unit Services among Commercially Insured Infants in the United States, 2016 – 2023

Background: Neonatal intensive care unit (NICU) treatment of infants has increased in the United States (US) in recent decades, and NICU admissions are now common for very low birthweight and very preterm infants. Characteristics of NICU usage in US commercial claims data have not been previously reported.

Objectives: To describe NICU utilization among liveborn infants identified in a large cohort of commercially-insured pregnancies.

Methods: This study used data from Optum’s Dynamic Assessment of Pregnancies and Infants (DAPI), a proprietary pregnancy identification process within the Optum Research Database, a health insurance claims data source. Pregnancies were restricted to those with at least 6 months of continuous enrollment prior to the start of pregnancy. Liveborn infants were linked to pregnancies using a proprietary process. Current Procedural Terminology (CPT®) NICU procedure codes were used to identify infants with NICU admissions during the first year of life. Gestational age at the time of birth, the timing of NICU admissions, and other commonly co-occurring diagnoses and procedures in NICU infants were assessed.

Results: Between 01 July 2016 and 31 October 2023, a total of 810,444 pregnancies with at least 6 months of continuous enrollment were observed. These pregnancies were linked to 404,746 liveborn infants (including multiples). Among these liveborn infants, a total of 45,393 (11.2%) had evidence of at least one NICU procedure code during the first year of life. Codes were most likely to appear in the first week of life (33.9% of all NICU codes), with over half appearing in the first 20 days following the end of pregnancy. The risk of NICU admission decreased with increasing gestational age, with 89.1% of very preterm infants ( < 32 weeks completed gestation) having a NICU visit code, while 6.3% of term infants (37 – 42 weeks completed gestation) had evidence of a NICU visit. Commonly co-occurring procedure codes among NICU infants included chest x-ray (57.4% of NICU infants), ophthalmologic and otologic diagnosis and treatment (36.6%), and respiratory intubation and mechanical ventilation (36.4%). Commonly co-occurring diagnoses among NICU infants included respiratory distress (60.6%), neonatal jaundice (57.9%), and feeding problems (44.6%).

Conclusions: Infant outcomes in the first year of life, including NICU admissions, are increasingly of interest in studies of perinatal exposure to medications. Approximately 11% of infants received NICU services in a large, commercially-insured cohort of US individuals. Infants were most likely to receive NICU services soon after birth, and pre-term infants were much more likely to be admitted to NICU. Future research will characterize length of NICU stays and differences in NICU procedures by term.