Improving 1-year survival at 22 weeks gestation: which perinatal interventions matter?

There is a need to identify the specific interventions that benefit survival chances at the borderline of viability to inform care for patients seeking proactive life-prolonging care.

We evaluated the impact of perinatal interventions on the 1-year survival among 22-week live births.

The study used the United States (U.S.) National Vital Statistics System Natality Data and included nonanomalous singleton live births at 22 weeks from 2019 to 2022. Cases were included if at least one of the interventions was documented: antenatal corticosteroids, cesarean delivery, neonatal intensive care unit (NICU) admission, assisted ventilation (immediate or for >6 hours), neonatal antibiotics for suspected newborn sepsis, or surfactant therapy. Cox proportional hazards regression models estimated adjusted hazard ratios (aHRs) for mortality within year one of life, controlling for maternal race, age, prior preterm birth, birth year, birth weight, infant sex, and individual treatment modalities.

Of the 4994 live births, 2769 received ≥1 intervention and comprised the study group. Within this group, 39.2% received antenatal corticosteroids, 28.4% had a cesarean delivery, 55.6% required immediate ventilation, 29.0% ventilation >6 hours, 78.7% NICU admission, 22.8% surfactant therapy, and 22.4% neonatal antibiotics. A significant dose-response relationship was observed with cases receiving 2 to 3 interventions and ≥4 interventions demonstrating improved 1-year survival probability compared to those receiving only 1 intervention (aHR 0.64; 95% CI [0.57-0.71] and aHR 0.41; 95% CI [0.36-0.46], respectively; all P<.001). Survival benefits were improved over time from 2019 to 2022, independent of intervention number (aHR 0.82; 95% CI [0.72-0.94], P=.004) or type (aHR 0.84; 95% CI [0.74-0.96], P=.009). Individually, antenatal corticosteroids (aHR 0.87; 95% CI [0.79-0.96]; P=.007), cesarean delivery (aHR 0.76; 95% CI [0.68-0.84]; P<.001), NICU admission (aHR 0.41; 95% CI [0.36-0.46]; P<.001), and newborn antibiotics (aHR 0.7; 95% CI [0.6-0.82]; P<.001) were significantly associated with improved survival at 1-year of life.

Antenatal corticosteroids, cesarean delivery, NICU admission, and neonatal antibiotics were each individually associated with improved 1-year survival at 22 weeks. A greater number of interventions cumulatively improved outcomes. These findings could help guide patient counseling and care management of fetuses and newborns at the cusp of viability. El resumen está disponible en Español al final del artículo.