Association of Antenatal Steroid Exposure With Survival Among Infants Receiving Postnatal Life Support at 22 to 25 Weeks' Gestation.

Importance: Although evidence of antenatal steroids (ANS) efficacy at 22 to 25 weeks' gestation is limited, increasingly these infants are treated with postnatal life support.

Objectives: To estimate the proportion of infants receiving postnatal life support at 22 to 25 weeks' gestation who had exposure to ANS, and to examine if the provision of ANS was associated with a higher rate of survival to hospital discharge and survival without major morbidities.

Design, Setting, And Participants: This multicenter observational cohort study consisted of 33 472 eligible infants liveborn at 431 US Vermont Oxford Network member hospitals between January 1, 2012, and December 31, 2016. We excluded infants with recognized syndromes or major congenital anomalies. Of the eligible infants, 29 932 received postnatal life support and were included in the analyses. Data analysis was conducted from July 2017 to July 2018.

Exposure: Antenatal steroids administered to the mother at any time prior to delivery.

Main Outcomes And Measures: Survival to hospital discharge, major morbidities among survivors, and the composite of survival to discharge without major morbidities.

Results: Among 29 932 infants who received postnatal life support, 51.9% were male, with a mean (SD) gestational age of 24.12 (0.86) weeks and mean (SD) birth weight of 668 (140) g; 26 090 (87.2%) had ANS exposure and 3842 (12.8%) had no ANS exposure. Survival to hospital discharge was higher for infants with ANS exposure (18 717 of 25 892 [72.3%]) compared with infants without ANS exposure (1981 of 3820 [51.9%]); the adjusted risk ratio for 22 weeks was 2.11 (95% CI, 1.68-2.65), for 23 weeks was 1.54 (95% CI, 1.40-1.70), for 24 weeks was 1.18 (95% CI, 1.12-1.25), and for 25 weeks was 1.11 (95% CI, 1.07-1.14). Survival to hospital discharge without major morbidities was higher for infants with ANS exposure (3777 of 25 833 [14.6%]) compared with infants without ANS exposure (347 of 3806 [9.1%]); the adjusted risk ratio for 22 through 25 weeks was 1.67 (95% CI, 1.49-1.87).

Conclusions And Relevance: Concordant receipt of ANS and postnatal life support was associated with significantly higher survival and survival without major morbidities at 22 through 25 weeks' gestation compared with life support alone. Although statistically higher with ANS, survival without major morbidities remains low at 22 and 23 weeks. There is an opportunity to reevaluate national obstetric guidelines, allowing for shared decision making at the edge of viability with concordant obstetrical and neonatal treatment plans.