Maternal corticosteroids to prevent intrauterine exposure to hyperthermia and inflammation: a randomized, double-blind, placebo-controlled trial.

OBJECTIVE: Intrauterine exposure to hyperthermia at term is associated with adverse neonatal neurologic outcomes. The objective of this study was to determine whether prophylactic maternal corticosteroid treatment prevents fetal exposure to hyperthermia and inflammatory cytokines after epidural analgesia.

STUDY DESIGN: A 2-phase, randomized, institutional review board-approved, double-blind, placebo-controlled trial was performed. Term nulliparous women were enrolled at epidural placement. Patients with a temperature of >99.4 degrees F or with diabetes mellitus were excluded. In phase 1, 25 mg methylprednisolone (low dose) or placebo was administered every 8 hours. In phase 2, the treatment dose was increased to 100 mg every 4 hours (high dose). Our primary outcome was a rate of intrapartum fever of >100.4 degrees F. Secondary outcomes were fetal interleukin-6 levels and the rate of neonatal bacteremia.

RESULTS: One hundred one patients were assigned randomly to placebo; 50 patients were assigned to the low-dose group, and 49 patients were assigned to the high-dose group. Treatment with the high dose resulted in a 90% reduction in maternal fever, compared with placebo and low dose therapy (2.0% vs 21.8% vs. 34.0%, respectively; P < .001). Neonatal sepsis evaluations were reduced significantly in the high-dose group (4.1% vs 17.8% vs 24%, respectively; P = .01), but the rates of asymptomatic bacteremia were increased (9.3% vs 0% vs 2.1%, respectively; P = .005). Median cord blood interleukin-6 levels were reduced with the high-dose steroid treatment, but this result was statistically significant only between the high-dose and placebo groups (24.0 +/- 38.5 vs 32.0 +/- 95.0 pg/mL, respectively; P = .02).

CONCLUSION: Prophylaxis with high-dose corticosteroids significantly reduces fetal exposure to hyperthermia and inflammation. However, maternal high-dose corticosteroids increase the rate of neonatal asymptomatic bacteremia. Stress-dose corticosteroid use in labor should trigger consideration of a screening neonatal blood culture.