2 - Antenatal Corticosteroid Exposure is Associated with Higher Infant Mortality Rates among Term Infants in the United States

Poster Number: 2
Publication Number: 2.337

Stephanie W. Pool, University of Alabama at Birmingham, Birmingham, AL, United States; AKM F. Rahman, University of Alabama at Birmingham, Vestavia, AL, United States; Samuel Gentle, UAB, Birmingham, AL, United States; Vivek V. Shukla, University of Alabama at Birmingham, Birmingham, AL, United States; Namasivayam Ambalavanan, University of Alabama School of Medicine, Birmingham, AL, United States; Waldemar A. Carlo, University of Alabama at Birmingham, Birmingham, AL, United States; Colm P. Travers, University of Alabama at Birmingham, Birmingham, AL, United States; Rachel Tindal, UAB Heersink School of Medicine, Birmingham, AL, United States

Background: Antenatal corticosteroids (ACS) decrease mortality among preterm infants but meta-analysis of randomized controlled trials noted a trend for increased fetal and neonatal mortality among infants exposed to ACS who subsequently delivered after 36 weeks’ gestation.

Objective: Test the hypothesis that term infants exposed to ACS will have a higher infant mortality rate (IMR) compared with term infants who are not exposed to ACS.

Design/Methods: This US population-based study included live-born infants from 37-42 weeks’ gestation in the Centers for Disease Control and Prevention (CDC) WONDER Expanded Linked Birth Infant Death 2017-2018 database. Infants with congenital anomalies and deaths due to congenital anomalies were excluded. We used logistic regression adjusted for gender, race, prenatal care, mode of delivery, multiple birth, and pregnancy risk factors (as defined by the CDC) to determine the difference in IMR between ACS exposed and unexposed infants. We used Chi-square or Fisher’s exact test to compare differences in categorical variables between groups.

Results: We included 6,712,347 term infants of whom 51,098 (0.8%) were exposed to ACS. Infants exposed to ACS had a higher infant mortality rate compared with infants unexposed to ACS (exposed 2.2/1000 versus unexposed 1.5/1000; adjusted odds ratio (aOR) 1.43; 95% confidence intervals (CI) 1.19-1.73; p< 0.001). This difference in IMR was primarily driven by a higher post-neonatal mortality rate among ACS exposed infants (1.6/1000) compared with unexposed infants (1.1/1000). Infants exposed to ACS had a higher rate of neonatal intensive care unit admission (10.3% versus 4.4%; p< 0.001), ventilation (5.7% versus 2.6%; p< 0.001), surfactant therapy (0.4% versus 0.1%; p< 0.001), and seizures (0.05% versus 0.03%; p=0.002) compared with unexposed infants.Conclusion(s): Exposure to antenatal corticosteroids was associated with a higher infant mortality rate among term infants in the United States. In addition, term infants exposed to antenatal corticosteroids had higher rates of neonatal morbidity compared with unexposed infants.