Association of antenatal corticosteroids with mortality and morbidities in very preterm infants born to women with hypertensive disorders of pregnancy: a multicenter prospective cohort study

Abstract

Background: Hypertensive disorders of pregnancy (HDP) is the most common cause of indicated preterm delivery, but the impact of prenatal steroid exposure on the outcomes of preterm infants born to HDP mothers, who may be at risk for intrauterine hypoxia-ischemia, remains uncertain. The study objective is to evaluate the mortality and morbidities in HDP for very preterm infants (VPIs) exposed to different course of ANS.

Methods: This is a prospective cohort study comprising infants with < 32 weeks gestation born to women with HDP only from 1 Jan. 2019 to 31 Dec. 2021 within 40 participating neonatal intensive care units (NICUs) in Sino-northern network. ANS courses included completed, partial, repeated, and no ANS. Univariate and multivariable analyses were performed on administration of ANS and short-term outcomes before discharge.

Results: Among 1917 VPIs born to women with HDP only, 987(51.4%) received a complete course of ANS within 48 h to 7 days before birth, 560(29.2%) received partial ANS within 24 h before delivery, 100(5.2%) received repeat ANS and 270 (14.1%) did not receive any ANS. Compared to infants who received complete ANS, infants unexposed to ANS was associated with higher odds of death (AOR 1.85; 95%CI 1.10, 3.14), Severe Neurological Injury (SNI) or death (AOR 1.68; 95%CI 1.29,3.80) and NEC or death (AOR 1.78; 95%CI 1.55, 2.89), the repeated ANS group exhibits a significant negative correlation with the duration of oxygen therapy days (correlation coefficient - 18.3; 95%CI-39.2, -2.1). However, there were no significant differences observed between the full course and partial course groups in terms of outcomes. We can draw similar conclusions in the non-SGA group, while the differences are not significant in the SGA group. From KM curve, it showed that the repeated group had the highest survival rate, but the statistical analysis did not indicate a significant difference.

Conclusions: Even partial courses of ANS administered within 24 h before delivery proved to be protective against death and other morbidities. The differences mentioned above are more pronounced in the non-SGA group. Repeat courses demonstrate a trend toward protection, but this still needs to be confirmed by larger samples.

Keywords: Antenatal corticosteroids; Hypertensive disorders of pregnancy; Mechanical ventilation; Morbility; Mortality; Pulmonary hemorrhage; Very preterm infants.