768 - The NICHD Extremely Preterm Birth Outcomes Tool: Evaluating Use and Understanding in Maternal Fetal Medicine and Neonatology

Publication Number: 2749.768

Hayley M. Wilcox, Tufts University School of Medicine, Boston, MA, United States; Rachana Singh, Tufts University School of Medicine, Boston, MA, United States; Christina Sakai, MassGeneral Hospital for Children, Boston, MA, United States; Jaclyn Boulais, Tufts Childrens Hospital, Jamaica Plain, MA, United States

Background: The NICHD Extremely Preterm Birth Outcomes Tool (the NICHD "calculator") developed in 2008 and revised in 2020, provides population-based estimates of survival and neurodevelopmental impairment (NDI) for infants born extremely preterm (EP). Previous studies suggest variable counseling practices and calculator use at EP gestational ages among perinatal specialists.

Objective: Evaluate how maternal fetal medicine specialists (MFMs) and neonatologists use, understand, and interpret the NICHD calculator when counseling at EP gestational ages.

Design/Methods: A national, cross-sectional survey of MFM and neonatology faculty and fellows was conducted from July 2022-June 2023 via Qualtrics. Participants were recruited via an Society for Maternal Fetal Medicine online database and the Organization of Neonatal-Perinatal Training Program Directors listserv, then through snowball sampling. Respondents were asked about resources used for counseling, knowledge of calculator terminology and output, and case-based vignettes with equivalent predicted outcomes. Descriptive data were stratified by specialty using Qualtrics "Crosstabs iQ."

Results: Seventy-nine MFMs and seventy-six neonatologists responded; 95% were practicing in an academic setting. For survival prognostication, 83% of MFMs and 87% of neonatologists used the NICHD calculator; for NDI, 75% and 89% respectively. Neonatologists demonstrated greater understanding of NDI definitions (78% vs 30% correct) and the corrected age of assessment (18-26 months). Most respondents misinterpreted "active treatment" as including maternal interventions and were unsure of the meaning of "survival without active treatment." Calculator use increased as gestational age and estimated fetal weight decreased. Survival estimates provided in the case vignettes were similar to the calculator's predictions, although more optimistic across specialties; only half of respondents reported directly referencing the tool.

Conclusion(s): Both specialties frequently use and highly value the NICHD calculator for counseling at EP gestational ages, though notable uncertainty persists regarding its terminology and NDI definitions. These findings highlight the need for joint educational initiatives and ongoing efforts to ensure informed use of population-based prognostic tools in EP counseling.

Figure 1. Sources used for survival prognostication by specialty.
MFM and Neonatology respondents reported where they gather information when estimating survival for EP infants. Both groups most often used the NICHD calculator and institutional data. MFMs relied more on specialty guidelines (SMFM, ACOG), while neonatologists also chose personal experience and VON data.

Figure 2. Sources used for neurodevelopmental (ND) prognostication by specialty.
MFM and Neonatology respondents reported where they gather information when discussing neurodevelopmental outcomes for EP infants. Both groups most often used the NICHD calculator, but neonatologists more frequently cited personal experience and VON data, while MFMs relied more on institutional data and specialty guidelines.

Figure 3. Median estimated survival by specialty for case vignettes.
Respondents estimated survival for a 23 week female and 24 week male with and without antenatal steroids. For the 23 week female, neonatology provided higher estimates than the calculator, while MFM estimation matched the calculator. Both specialties had higher estimates than the NICHD calculator for the 24 week male.