540 - Timing of a Single Course Antenatal Steroids and Neurodevelopmental Outcomes of Children Born Preterm: A National Cohort Study

Publication Number: 540.6735

Aseel M. Sa'deh, Dalhousie University Faculty of Medicine, halifax, NS, Canada; Walid El-Naggar, Dalhousie University Faculty of Medicine, Halifax, NS, Canada; Marc Beltempo, McGill University Faculty of Medicine and Health Sciences, Monreal, PQ, Canada; Jehier Afifi, Dalhousie University Faculty of Medicine, Halifax, NS, Canada; Prakesh S. Shah, Mount Sinai Hospital, Toronto, ON, Canada; Krystal Van Den Heuvel, Dalhousie University Faculty of Medicine, Hammonds Plains, NS, Canada; Seungwoo Lee, Mount Sinai Hospital, Toronto, ON, Canada

Background: Maternal antenatal steroids (ANS) before preterm birth are known to improve survival, morbidity and the composite outcome of death or neurodevelopmental impairment (NDI), mainly related to decreased mortality. There is paucity of data on the association of different timing and completeness of a single course of ANS with neurodevelopmental outcomes among survivors.

Objective: To compare the rates of NDI and significant NDI (sNDI) between extreme preterm infants with different ANS to birth intervals and to examine the association of differential ANS exposure with neurodevelopment in these infants.

Design/Methods: A national retrospective cohort of infants (230-286 weeks) born between 2010 and 2020, admitted to Canadian Neonatal Network units and completed neurodevelopmental assessment at 18-24 months’ corrected age in Canadian Neonatal Follow Up Network (CNFUN) centers. Infants were grouped and compared based on different ANS exposure (none, partial < 2 days, complete 2-7 days and complete >7 days). Co primary outcomes are NDI (any of cerebral palsy (CP), Bayley scores < 85 in any domain, hearing or visual impairment) and sNDI (any of non-ambulatory CP, Bayley scores < 70 in any domain, hearing aid/cochlear implant, bilateral visual impairment). Multivariable regression models with GEE to account for clustering by site adjusted for potential confounders (maternal education, diabetes, hypertension, gestational age, infant sex, singleton, rupture of membranes >24 hours, intrapartum magnesium sulfate, outborn status, and SNAPEII scores) were used to estimate adjusted OR (95% CI). The complete ANS 2-7 days prior to birth was the reference group.

Results: Among 6787 included infants, 10% did not receive any ANS, 21% received partial course < 2 days, 46% received complete course 2-7 days before birth and 23% received complete course >7 days (Figure 1). Maternal and neonatal baseline characteristics are shown in Table 1. Table 2 compares the outcomes between the four ANS exposure groups. After adjustment for potential confounders, there was no difference in NDI or sNDI between groups. However, partial ANS < 2 days was associated with higher odds of CP (aOR 1.66 (95% CI) 1.09 - 2.54) and severe language delay (aOR 1.27 (95% CI) 1.004 - 1.60) compared to complete ANS within 2-7 days before birth, probably due to confounding by indication.

Conclusion(s): Among extreme preterm infants who survived to 18-24 months, differential ANS exposure was not associated with NDI or sNDI . The improved survival associated with ANS does not come with a tradeoff of increased adverse neurodevelopment in children born preterm.

Figure 1: Flow Chart of the Study Population


Table 1: Population Characteristics
Data are presented as percentage (n/N), mean (SD) or median (IQR)
* Welch’s ANOVA was used due to the unequal variances across the groups instead of standard ANOVA
** Ref to College education or higher ^ receipt of chest compression or epinephrine


Table 2: Neurodevelopmental Outcomes at 18-24 Months Corrected Age Based on Differential ANS Exposure
Data are presented as percentage (n/N) or median (IQR)*