Title:
Neonatal outcomes at extreme prematurity by gestational age in a contemporary cohort

Authors:

Elizabeth B. Ausbeck MD¹, P. Hunter Allman MS², Jeff M. Szychowski PhD^1,2, Akila Subramaniam MD, MPH¹, Anup Katheria MD³

Institutions:

1Department of Obstetrics and Gynecology, Center for Women’s Reproductive Health, University of Alabama at Birmingham, Birmingham, AL

2Department of Biostatistics, University of Alabama at Birmingham, Birmingham, AL

3Neonatal Research Institute, Sharp Mary Birch Hospital for Women and Newborns, San Diego, CA

Background:

• Extremely preterm neonates (<28 weeks gestational age) account for <1% of all deliveries
• However, these neonates have the highest risk of death or severe morbidity
• Current counseling on risks of these adverse events utilizes data that is not based on a contemporary cohort

• To describe the rates of neonatal death and severe neonatal morbidity by gestational age (GA) at delivery in a contemporary patient population

Study Design:

• Secondary analysis of multicenter RCT (PREMOD2) that compared umbilical cord milking to delayed cord clamping in premature newborns
• Inclusion criteria:

• • Delivery GA of 23⁰-27⁶ weeks

• Exclusion criteria:

• • Major congenital anomalies
  • Severe placental abruption
  • Transplacental incision
  • Umbilical cord prolapse
  • Hydrops fetalis
  • Placenta accrete with bleeding accrete
  • Monochorionic multiple gestations
  • Fetal or maternal risk for severe compromise at delivery
  • Inability to return for 24-month neurodevelopmental testing

• Primary outcomes:

• • Neonatal death
  • Composite of severe neonatal morbidity (components in Figure)

• Analysis:

• • Incidence of primary outcomes were stratified by GA in weeks
  • Planned secondary analysis to assess differences in the primary outcomes in appropriate vs small for GA (SGA) neonates with the Cochran-Mantel-Haneszel test

Results:

• Of 474 neonates in the RCT, 182 (38%) were included in this analysis
• Mean delivery GA: 25.7±1.4 weeks (median 25.9 weeks, IQR 24.6-27.0)
• Mean birthweight: 812±211 grams
• Neonatal death occurred in 27 (15%) neonates
• Severe morbidity occurred in 139 (76%) neonates
• Figure, top panel

• • Rates of mortality and morbidity declined with increasing GA

• Figure, bottom panel

• • SGA infants (n=25) had significantly higher neonatal mortality across GAs (p =0.005)
  • However, composite morbidity was not significantly different between SGA and non-SGA infants (p=0.24)

Conclusions:

• Death and severe neonatal morbidity declined with advancing GA
• Higher rates of death in SGA infants
• Although limited in scope, we present updated estimates for neonatal death and severe morbidity in a contemporary patient population, which may be used to effectively counsel patients for informed decision making