Association of Antenatal Corticosteroid Exposure and Infant Survival at 22 and 23 Weeks

National Trends in Survival and Short-Term Outcomes of Periviable Births ≤24 Weeks Gestation in the United States, 2009 to 2018

OBJECTIVE

Data from the academic medical centers in the United States showing improvements in survival of periviable infants born at 22 to 24 weeks GA may not be nationally representative since a substantial proportion of preterm infants are cared for in community hospital-based neonatal intensive care units. Our objective was to examine the national trends in survival and other short-term outcomes among preterm infants born at ≤24 weeks gestational age (GA) in the United States from 2009 to 2018.

STUDY DESIGN

This was a retrospective, repeated cross-sectional analysis of the National Inpatient Sample for preterm infants ≤24 weeks GA. The primary outcome was the trends in survival to discharge. Secondary outcomes were the trends in the composite outcome of death or one or more major morbidity (bronchopulmonary dysplasia, necrotizing enterocolitis stage ≥2, periventricular leukomalacia, severe intraventricular hemorrhage, and severe retinopathy of prematurity). The Cochran-Armitage trend test was used for trend analysis. p-Value <0.05 was considered significant.

RESULTS

Among 71,854 infants born at ≤24 weeks GA, 34,251 (47.6%) survived less than 1 day and were excluded. Almost 93% of those who survived <1 day were of ≤23 weeks GA. Among the 37,603 infants included in the study cohort, 48.1% were born at 24 weeks GA. Survival to discharge at GA ≤ 23 weeks increased from 29.6% in 2009 to 41.7% in 2018 (p < 0.001), while survival to discharge at GA 24 weeks increased from 58.3 to 65.9% (p < 0.001). There was a significant decline in the secondary outcomes among all the periviable infants who survived ≥1 day of life.

CONCLUSION

Survival to discharge among preterm infants ≤24 weeks GA significantly increased, while death or major morbidities significantly decreased from 2009 to 2018. The postdischarge survival, health care resource use, and long neurodevelopmental outcomes of these infants need further investigation.

KEY POINTS

· Survival increased significantly in infants ≤24 weeks GA in the United States from 2009 to 2018.. · Death or major morbidity in infants ≤24 weeks GA decreased significantly from 2009 to 2018.. · Death or surgical procedures including tracheostomy, VP shunt placement, and PDA surgical closure in infants <=24 weeks GA decreased significantly from 2009 to 2018..

Antenatal Corticosteroids at 21-23 Weeks of Gestation

Neonates born at the cusp of viability are at particularly high risk of severe morbidity and mortality. With advances in medicine and technology, the ability to resuscitate smaller, more premature neonates has become possible, and survival as early as 21 weeks of gestation has been reported. Although administration of antenatal corticosteroids has been shown to reduce the risk of morbidity and mortality at later gestational ages, neonates born before 24 weeks of gestation have not been included in randomized clinical trials. Changing clinical practices surrounding neonatal resuscitation with intervention offered after birth at earlier gestational ages has prompted re-evaluation of the use of antenatal corticosteroids at these very early gestational ages. Recent observational data demonstrate that antenatal corticosteroids administered before deliveries at or after 22 weeks of gestation are associated with lower risks of neonatal mortality, although survival with severe morbidity remains high. Future research is needed to determine the efficacy of antenatal corticosteroids for deliveries before 22 weeks of gestation and should evaluate the timing of corticosteroid administration. Furthermore, efforts should be made to include diverse populations and clinically meaningful long-term outcomes. At this time, the decision surrounding antenatal corticosteroids for threatened periviable deliveries should incorporate multidisciplinary counseling with the goal of achieving concordant prenatal and postnatal management aligned with the patient's desires.

Association of Antenatal Steroid Exposure at 21 to 22 Weeks of Gestation With Neonatal Survival and Survival Without Morbidities

Importance

The provision of antenatal corticosteroids to pregnant patients at gestational age (GA) 22 6/7 weeks or less remains controversial and lacks support from randomized clinical trials.

Objective

To compare rates of survival and survival without major morbidities among infants born at GA 22 0/7 to 23 6/7 weeks after exposure to antenatal steroids at 22 6/7 weeks' gestation or less vs no exposure to antenatal steroids.

Design, Setting, and Participants

This cohort study enrolled infants born at GA 22 0/7 to 23 6/7 weeks between January 1, 2016, and December 31, 2019, at centers in the National Institute of Child Health and Human Development Neonatal Research Network. Infants who did not receive intensive care and infants with antenatal steroid exposure after GA 22 6/7 weeks were excluded.

Exposure

Infants were classified as having no, partial, or complete exposure to antenatal steroids.

Main Outcomes and Measures

The primary outcome was survival to discharge. The main secondary outcome was survival without major neonatal morbidity. The associations of differential exposures to antenatal steroids with outcomes were evaluated using logistic regression, adjusting for GA, sex, race, maternal education, small for GA status, mode of delivery, multiple birth, prolonged rupture of membranes, year of birth, and Neonatal Research Network center.

Results

A total of 431 infants (mean [SD] GA, 22.6 [0.5] weeks; 232 [53.8%] boys) were included, with 110 infants (25.5%) receiving no antenatal steroids, 80 infants (18.6%) receiving partial antenatal steroids, and 241 infants (55.9%) receiving complete antenatal steroids. Seventeen infants were exposed to antenatal steroids at GA 21 weeks. Among infants exposed to complete antenatal steroids, 130 (53.9%) survived to discharge, compared with 30 infants (37.5%) with partial antenatal steroid exposure and 239 infants (35.5%) with no antenatal steroids. Infants born after complete antenatal steroid exposure, compared with those without antenatal steroid exposure, were more likely to survive to discharge (adjusted odds ratio [aOR], 1.95 [95% CI, 1.07-3.56]) and to survive without major morbidity (aOR, 2.74 [95% CI, 1.19-6.30]).

Conclusions and Relevance

In this retrospective cohort study, among infants born between GA 22 0/7 and 23 6/7 weeks who received intensive care, exposure to a complete course of antenatal steroids at GA 22 6/7 weeks or less was independently associated with greater odds of survival and survival without major morbidity. These data suggest that the use of antenatal steroids in patients at GA 22 6/7 weeks or less could be beneficial when active treatment is considered.