Does a Split-Week Gestational Age Model Provide Valuable Information on Neurodevelopmental Outcomes in Extremely Preterm Infants?

Paige Church,Elizabeth Asztalos,Leonora Hendson,Alberto Nettel Aguirre,Jessie van Dyk,Rudaina Banihani,Hussein Zein,Sumesh Thomas

doi:10.3390/children8090731

Abstract

Our primary objective for this follow-up study was to compare the neurodevelopmental outcomes of a surviving cohort of infants using a split-week gestational model (early versus late) gestational age (GA) and the standard completed GA categorization. Neurodevelopmental outcomes using a split-week GA model defined as early (X, 0–3) and late (X, 4–6), with X being 23–26 weeks GA, were compared to outcomes using completed weeks GA. In total, 1012 infants were included in the study. Statistically significant differences were noted in outcomes between the early and late split of the gestational week at 23 weeks (early vs. late), with 13.3% vs. 54.5% for no neurodevelopmental impairment, and 53.3% vs. 22.7% for significant impairment (p = 0.034), respectively. There were no differences seen in the split week model for 24, 25, and 26 weeks. A trend towards improved neurodevelopmental outcomes was seen with each increasing gestation week. The split-week model did not provide additional information for pregnancies and infants between 24 and 26 weeks gestation. It did, however, provide information for counsel for infants at 23 weeks gestation, showing benefits in the late versus early half of the week.

Highlights

Over the last two decades, survival rates for infants born less than 27 weeks gestation have steadily improved
23 and 26 weeks gestation and discharged home, using a split-week gestational model gestational age (GA) in comparison to outcomes based on standard completed GA categorization. This is the follow-up phase of the initial retrospective cohort study of the live-born infants at GA 230/7 to 266/7 weeks who were admitted to the neonatal intensive care units (NICUs) at the Foothills Medical Centre, Calgary, Alberta and Sunnybrook Health
Of the 1450 infants born and admitted to the NICU at both the Foothills Medical Centre and Sunnybrook Health Sciences Centre over the study period with a gestational age of 23–26 weeks, 1345 were eligible for inclusion in the neonatal phase; 235 infants died in the neonatal period, leaving 1110 eligible for inclusion in the neurodevelopmental phase

Summary

Introduction

Over the last two decades, survival rates for infants born less than 27 weeks gestation have steadily improved. Recent population studies evaluating neurodevelopmental outcomes in infants born at less than 25–26 weeks gestation focus on three main areas of disability: impairment of cognition, motor function, and neurosensory function. These findings relate to the objective assessment of cognitive function, a measure of vision and hearing impairment including the need for aids, and motor challenges primarily in the form of cerebral palsy and other categories of motor challenges relating to ambulation [1–6]. Several studies point out that infants born in the latter part of a gestational week have improved survival outcomes compared to those born in the early part of the week [9,10] These studies did not examine the long-term consequences of this difference in their survivors. Long-term outcome information is likely to help parents faced with difficult decisions with the potential birth of a baby at the margins of viability, during neonatal care, and at the time of discharge from the hospital

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