Would you prescribe antenatal steroids to a pregnant patient at high risk for delivering at 22 weeks’ gestation?

^{Photo: Iryna Inshyna/Shutterstock}

For many decades, the limit of newborn viability was at approximately 24 weeks’ gestation. Recent advances in pregnancy and neonatal care suggest that the new limit of viability is 22 (22 weeks and 0 days to 22 weeks and 6 days) or 23 (23 weeks and 0 days to 23 weeks and 6 days) weeks of gestation. In addition, data from observational cohort studies indicate that for infants born at 22 and 23 weeks’ gestation, survival is dependent on a course of antenatal steroids administered prior to birth plus intensive respiratory and cardiovascular support at delivery and in the neonatal intensive care unit (NICU).

Antenatal steroids: Critical for survival at 22 and 23 weeks of gestation

Most studies of birth outcomes at 22 and 23 weeks’ gestation rely on observational cohorts where unmeasured differences among the maternal-fetal dyads that received or did not receive a specific treatment confounds the interpretation of the data. However, data from multiple large observational cohorts suggest that between 22 and 24 weeks of gestation, completion of a course of antenatal steroids will optimize infant outcomes. Particularly noteworthy was the observation that the incremental survival benefit of antenatal steroids was greatest at 22 and 23 weeks’ gestation (TABLE 1).¹ Similar results have been reported by Rossi and colleagues (TABLE 2).²

The importance of a completed course of antenatal steroids before birth was confirmed in another cohort study of 431 infants born in 2016 to 2019 at 22 weeks and 0 days’ to 23 weeks and 6 days’ gestation.³ Survival to discharge occurred in 53.9% of infants who received a full course of antenatal steroids before birth and 35.5% among those who did not receive antenatal steroids.^.3 Survival to discharge without major neonatal morbidities was 26.9% in those who received a full course of antenatal steroids and 10% among those who did not. In this cohort, major neonatal morbidities included severe intracranial hemorrhage, cystic periventricular leukomalacia, severe bronchopulmonary dysplasia, surgical necrotizing enterocolitis, or severe retinopathy of prematurity requiring treatment.

The American College of Obstetricians and Gynecologists (ACOG) recommends against antenatal steroids prior to 22 weeks and 0 days gestation.⁴ However, some neonatologists might recommend that antenatal steroids be given starting at 21 weeks and 5 days of gestation if birth is anticipated in the 22nd week of gestation and the patient prefers aggressive treatment of the newborn.

Active respiratory and cardiovascular support improves newborn outcomes

To maximize survival, infants born at 22 and 23 weeks’ gestation always require intensive active treatment at birth and in the following days in the NICU. Active treatment may include respiratory support, surfactant treatment, pressors, closure of a patent ductus arteriosus, transfusion of red blood cells, and parenteral nutrition. In one observational cohort study, active treatment at birth was not routinely provided at 22 and 23 weeks’ gestation but was routinely provided at later gestational ages (TABLE 3A).⁵ Not surprisingly, active treatment, especially at early gestational ages, is associated with improved survival to discharge. For example, at 22 weeks’ gestation, survival to discharge in infants who received or did not receive intensive active treatment was 28% and 0%, respectively.⁵ However, specific clinical characteristics of the pregnant patient and newborn may have influenced which infants were actively treated, confounding interpretation of the observation. In this cohort of extremely premature newborns, survival to hospital discharge increased substantially between 22 weeks and 26 weeks of gestational age (TABLE 3B).⁵

Many of the surviving infants needed chronic support treatment. Among surviving infants born at 22 weeks and 26 weeks, chronic support treatments were being used by 22.6% and 10.6% of infants, respectively, 2 years after birth.⁵ For surviving infants born at 22 weeks, the specific chronic support treatments included gastrostomy or feeding tube (19.4%), oxygen (9.7%), pulse oximeter (9.7%), and/or tracheostomy (3.2%). For surviving infants born at 26 weeks’ gestation, the specific chronic support treatments included gastrotomy or feeding tube (8.5%), pulse oximeter (4.4%), oxygen (3.2%), tracheostomy (2.3%), an apnea monitor (1.5%), and/or ventilator or continuous positive airway pressure (1.1%).⁵

Continue to: Evolving improvement in infant outcomes...