Category: Prematurity
Poster Session II
The NICHD Extremely Preterm Birth Outcomes Tool (“calculator”)—used for periviable counseling—predicts neonatal survival (PredNS) using gestational age (GA), birthweight (BW), sex, singleton, and steroids. PredNS improves with advancing gestation, but, patients often do not receive updated counseling. Differences in PredNS at time of counseling and delivery can affect decisions. The objectives were to assess: 1) the relative difference in PredNS using data available at time of counseling (PredNSc) vs time of delivery (PredNSd) and, 2) if clinical factors outside the calculator were associated with relative difference in PredNS ≥ 10%.
Study Design:
This retrospective cohort study of deliveries between 22.0-25.6 wks (Jan 2017 to Mar 2022) included singletons with estimated fetal weight (EFW) and BW between 401-1000 grams. Subjects with lethal fetal anomaly, fetal demise, or no EFW within 4 wks of delivery were excluded. The calculator was used to estimate PredNSc (EFW & GA at EFW) and PredNSd (BW & GA at delivery). All other inputs were unchanged. Active treatment was assumed. Primary outcome was an absolute value of relative difference (AVRD) in PredNS ≥ 10%, calculated as: |[(PredNSc – PredNSd) / PredNSd]*100|. Bivariate analysis and multivariable Poisson regression models with robust error variance were used. Adjusted relative risk (aRR) with 95% confidence intervals were calculated.
Results:
Of the 288 deliveries, 167 (58%) met eligibility criteria. 97 (58%) had AVRD in PredNS ≥ 10%. Several potential risk factors for the primary outcome were identified (Table 1). After multivariable adjustment, placental abruption (aRR 0.52, 95% CI 0.30-0.92) was found to decrease the risk of the primary outcome. Factors associated with increased risk included p</span>rior CD (aRR 1.85, 95% CI 1.43-2.39) and time from EFW to delivery ≥ 7 days (aRR 1.37, 95% CI 1.11-1.69) (Table 2).
Conclusion:
We identified several clinical factors not included in the calculator that can be known prior to delivery and are associated with a difference in PredNS. These results have implications for counseling in the periviable period.
Nayla G. Kazzi, MD (she/her/hers)
McGovern Medical School at The University of Texas Health Science Center at Houston (UTHealth)
Houston, Texas, United States
Sarah Nazeer, MD (she/her/hers)
Maternal-Fetal Medicine Fellow
Department of Obstetrics, Gynecology & Reproductive Health Sciences, University of Texas
Houston, Texas, United States
Hailie Ciomperlik, BA
Univ. of Texas Medical School at Houston
Houston, Texas, United States
John Biebighauser, BS
University of Texas-Houston Medical School
Houston, Texas, United States
Chloe Denham, BS
University of Texas-Houston Medical School
Houston, Texas, United States
Baha M. Sibai, MD
Professor
Department of Obstetrics, Gynecology and Reproductive Sciences, McGovern Medical School at The University of Texas Health Science Center at Houston (UTHealth)
Houston, Texas, United States
Suneet P. Chauhan, MD
Professor
Department of Obstetrics, Gynecology and Reproductive Sciences, McGovern Medical School at The University of Texas Health Science Center at Houston (UTHealth)
Houston, Texas, United States