384 - Prediction of early cord clamping in extremely preterm infants

Publication Number: 384.6119

Anup Katheria, Sharp Mary Birch Hospital for Women & Newborns, San Diego, CA, United States; Rebecca A. Dorner, Sharp Mary Birch Hospital for Women & Newborns, San Diego, CA, United States; William Grobman, The Warren Alpert Medical School of Brown University, Providence, RI, United States; Matthew Rysavy, McGovern Medical School at the University of Texas Health Science Center at Houston, Houston, TX, United States; Jenny K.. Koo, Sharp Mary Birch, San Diego, CA, United States; Grecio Sandoval, The George Washington University, Washington, DC, United States; Sara B.. DeMauro, Perelman School of Medicine at the University of Pennsylvania, Philadelphia, PA, United States; Abhik Das, RTI International, North Potomac, MD, United States; Henry C. Lee, University of California, San Diego School of Medicine, La Jolla, CA, United States; Michael Cotten, Duke university, Durham, NC, United States; Laura N. Calvo, Duke University School of Medicine, Durham, NC, United States; Myra H. Wyckoff, UT Southwestern, Dallas, TX, United States; shampa saha, RTI international, Durham, NC, United States; NICHD Neonatal Research Network, National Institute of Child Health and Human Development, Bethesda, MD, United States

Background: Obstetrical providers often do not perform delayed cord clamping (DCC) on preterm infants, potentially due to pre-delivery anticipated need for immediate resuscitation. However, most preterm infants do not have asphyxia precluding DCC. Determining which factors that may predispose to early cord clamping (ECC) could help providers be aware of infants who are more likely to miss DCC.

Objective: (1) To identify prenatal risk factors for ECC in extremely preterm infants (23-28 weeks) born in NRN hospitals from 2016-2023. (2) To use these factors to construct a model predicting which infants have the highest risk of ECC.

Design/Methods: Data from the NRN registry were used. Stepwise logistic regression and classification and regression tree (CART) analysis was performed to identify variables most associated with ECC and build a parsimonious model that could be used to identify which preterm infants had the highest risk of ECC. Statistical significance was set at P< 0.05.

Results: There were 12,750 infants eligible for analysis (DCC, N=4213, ECC, N=8537). Table 1 presents maternal characteristics in the two study groups. Table 2 presents the results of logistic regression analysis which was performed to select predictors for ECC. Table 3 shows the relative importance of the predictors of ECC chosen by the CART model. CART analysis helps choose the most important predictors based on its importance in predicting the outcome. The variable importance ranking is a summary of a variable’s contribution to the overall tree when all nodes are examined. On the CART model, lack of magnesium sulfate administration, lower gestational age, cesarean delivery, antepartum hemorrhage, and time to delivery < 6 hours after mother’s admission to the hospital in that order, were the factors that contributed the most to identifying which infants received ECC. Several additional factors were relevant, including male fetus and socially constructed factors such as race/ethnicity.

Conclusion(s): Our results from the logistic regression analysis and CART suggest that there are multiple factors among extremely preterm pregnancies – including lack of antenatal magnesium, earlier gestation, cesarean delivery, antenatal hemorrhage, and shorter time to delivery after mother’s admission to the hospital – that can be used to identify infants more likely to miss DCC. Further, there is evidence that race and ethnicity contributed to differences in who received DCC. Pre-briefing, providing verbal reassurance about infant’s status and/or scrubbing in and providing stimulation or respiratory support may decrease rates of unnecessary ECC.

Table 1. Maternal Characteristics
Legend: MgSo4: Magnesium Sulfate; GA: gestational age; SGA: Small for gestational age

Table 2. Risk Factors for Early Cord Clamping
CART ROC (Area Under Curve) =0.66(0.65,0.67)
Legend: MgSo4: Magnesium Sulfate; GA: gestational age; Gestational age categorized as 22,23,24,25,26,27,28. Maternal age categorized as 14-19,20-24,25-30, 31-35,36-40, 41-45, > 45 years. Time to delivery after admission to the hospital: categorized as: <6 hrs, 6-12, 12-24, 24-48, 48-72, 72-100,100-150, 150-200, >200 hrs.

Figure 1. CART Tree
CART_Tree-fig.jpeg

Table 1. Maternal Characteristics
Legend: MgSo4: Magnesium Sulfate; GA: gestational age; SGA: Small for gestational age

Table 2. Risk Factors for Early Cord Clamping
CART ROC (Area Under Curve) =0.66(0.65,0.67)
Legend: MgSo4: Magnesium Sulfate; GA: gestational age; Gestational age categorized as 22,23,24,25,26,27,28. Maternal age categorized as 14-19,20-24,25-30, 31-35,36-40, 41-45, > 45 years. Time to delivery after admission to the hospital: categorized as: <6 hrs, 6-12, 12-24, 24-48, 48-72, 72-100,100-150, 150-200, >200 hrs.

Figure 1. CART Tree
CART_Tree-fig.jpeg