174 - Association of Social Distancing with Extremely Preterm Live Births and Intrapartum Stillbirths in the Initial COVID-19 Pandemic Period

Poster Number: 174
Publication Number: 174.234

Vivek V. Shukla, University of Alabama at Birmingham, Birmingham, AL, United States; Benjamin A. Carper, RTI International, RTP, NC, United States; Matthew Rysavy, McGovern Medical School at the University of Texas Health Science Center at Houston, Houston, TX, United States; Edward F. Bell, University of Iowa Roy J. and Lucille A. Carver College of Medicine, Iowa City, IA, United States; Abhik Das, RTI International, North Potomac, MD, United States; Ravi M. Patel, Emory University and Children's Healthcare of Atlanta, Atlanta, GA, United States; Carl DAngio, University of Rochester School of Medicine and Dentistry, Rochester, NY, United States; Kristi L. Watterberg, University of New Mexico School of Medicine, Albuquerque, NM, United States; Michael Cotten, Duke University School of Medicine, Durham, NC, United States; Stephanie L. Merhar, Cincinnati Children's Hospital Medical Center, Cincinnati, OH, United States; Myra H. Wyckoff, University of Texas Southwestern Medical School, Dallas, TX, United States; Pablo J. Sanchez, Nationwide Children's Hospital -OSU, Columbus, OH, 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; NICHD Neonatal Research Network, NICHD, Bethesda, MD, United States

Background: COVID-19 pandemic-related increased social distancing could have changed the incidence of extremely preterm live births.

Objective: To test the hypothesis that increased social distancing is associated with a lower incidence of extremely preterm live births at the NICHD Neonatal Research Network sites during the initial COVID-19 pandemic period.

Design/Methods: Study Design Type: Prospective observational study. Eligibility Criteria: All extremely preterm (≤ 28 6/7 weeks gestational age) live births (EPLB) and intrapartum stillbirths (EPIS) at the NICHD Neonatal Research Network sites (calendar weeks 9 to 30 of 2018, 2019, and 2020) were included. Comparison: The incidence of EPLB and EPIS as a proportion of total births during the pandemic period (calendar weeks 9 to 30 of 2020) was compared to that of the reference period (corresponding calendar weeks of 2018 and 2019). Maternal and fetal-neonatal characteristics and neonatal outcomes were compared between the periods. We correlated the change in the incidence of EPLB and EPIS over time with the social distancing as measured by site state-specific social distancing index (SDI), defined as the extent to which residents of the state practiced social distancing, computed from six mobility metrics (including % staying home, % reduction of all trips compared to pre-COVID-19 benchmark, % reduction of work trips, % reduction of non-work trips, % reduction of travel distance, and % reduction of out-of-county trips, available from https://data.covid.umd.edu).

Results: For the analyzed period, EPLB and EPIS as percentages of total births did not significantly decrease in the pandemic period (1.83 to 1.77%, p=0.40, and 0.10 to 0.06%, p=0.05, respectively). The SDI (Mean ± SD=39.9 ± 11.3 for the pandemic period) was not significantly cross-correlated with the percent change of EPLB (coefficient=0.26, 95% CI=-0.16, 0.67) and EPIS (coefficient=-0.18, 95% CI=-0.59, 0.24, Figure 1). The mean gestational age for all extremely preterm births was higher in the pandemic period until calendar week 18 (Mean ± SD= 26.0 ±1.5 vs. 25.7 ± 1.4 weeks, all p< 0.01) and was positively cross-correlated with the SDI (coefficient=0.55, 95% CI=0.13, 0.97, Figure 2), but the mean gestational age was not significantly different between the study periods (Table 1).Conclusion(s): Increased social distancing was not associated with a lower incidence of extremely preterm live birth but was associated with a higher extremely preterm birth gestational age in the initial COVID-19 pandemic period.
Table 1: Baseline Characteristics and Outcomes
Figure 1: Correlation of Social Distancing Index with Extremely Preterm Live births and Intrapartum Stillbirths.The social distancing index was not significantly cross-correlated with the percent change of extremely preterm live births (coefficient=0.26, 95% CI=-0.16, 0.67) and intrapartum stillbirths (coefficient=-0.18, 95% CI=-0.59, 0.24).