The interval between a single course of antenatal steroids and delivery and its association with neonatal outcomes

Objective:

This study was undertaken to determine whether the benefits of a single course of antenatal steroid treatment for neonatal respiratory morbidity diminish beyond seven days.

Study design:

A retrospective chart review was performed of all deliveries less than 34 weeks' gestation where delivery occurred after completing a single course of antenatal steroids (dexamethasone or betamethasone). Maternal and neonatal charts were reviewed, treatment course was confirmed, and neonatal morbidities were collected.

Results:

Of 197 neonates whose mothers received a full course of antenatal steroids, 98 delivered within seven days and 99 delivered more than seven days after the initial dose. The two groups were similar in gestational age at delivery (30 weeks 0 days vs 30 weeks 4 days). The groups were also similar in maternal age, race, payor status, type of steroid given, route of delivery, gender, and birth weight. Overall, infants delivering within seven days had a lower incidence of receiving respiratory support for more than 24 hours (62% vs 81%, P <.01), but there were no significant differences between the groups in surfactant treatment (39% vs 47%), use of mechanical ventilation (49% vs 59%), necrotizing enterocolitis (6% vs 4%), intraventricular hemorrhage (15% vs 20%), oxygen dependence at 28 days (24% vs 23%) or at 36 weeks estimated gestational age (13% vs 12%), length of stay (34 days vs 38 days), or mortality (2 vs 0). These results were no different when evaluating only infants delivered before 30 weeks.

Conclusion:

Among infants exposed to a single course of antenatal steroids, delivering more than seven days after initiation of treatment was associated with an increased need for short-term respiratory support, but not other measures of neonatal morbidity. These data challenge the concept of diminishing efficacy of steroids after seven days, and question the need for considering a rescue course.

Peaceman AM, Bajaj K, Kumar P et al. American Journal of Obstetrics and Gynecology, vol 193, no 3, part 2, Sep 2005, pp 1165-1169.

Author abstract. © Elsevier 2005.