Effectiveness of antenatal corticosteroid administration after preterm premature rupture of the membranes

OBJECTIVE: This study was undertaken to determine the effect of antenatal b etamethasone administration on the incidences of respiratory distress syndr ome, intraventricular hemorrhage, and perinatal infectious morbidity in the setting of preterm premature rupture of membranes. STUDY DESIGN: We performed a nonconcurrent prospective analysis of women wi th singleton pregnancies who were delivered between 24 and 32 weeks' gestat ion after preterm premature rupture of membranes. Patients were subdivided into 2 groups according to betamethasone exposure: (1) none (control group) and (2) two 12-mg doses in a 24-hour interval on admission (single-course group). Patients who received greater than or equal to2 doses of betamethas one were excluded. All patients received broad-spectrum prophylactic antibi otics. Data were analyzed with the Student t test, the chi (2) test, and th e Fisher exact test. Multiple logistic regression analyses incorporated mul tiple variables considered risk factors for respiratory distress syndrome a nd intraventricular hemorrhage. P < .05 for all 2-tailed tests was consider ed significant. RESULTS: A total of 362 patients were included, with 203 in the control gro up and 159 in the single-course group. Patients in these groups were delive red at 31.0 +/- 3.0 and 30.2 +/- 2.7 (mean +/- SD) weeks' gestation, respec tively, The groups were similar with respect to selected demographic charac teristics, latency until delivery, mode of delivery, birth weight, and mate rnal group B streptococcal colonization status. Univariate analysis demonst rated significant decreases in the frequencies of both respiratory distress syndrome (odds ratio. 0.31; 95% confidence interval, 0.2-0.5) and grade II I/IV intraventricular hemorrhage (odds ratio, 0.14; 95% confidence interval , 0.1-0.6) in the single-course group. The frequencies of early neonatal se psis, chorioamnionitis, endometritis, and neonatal death were similar betwe en groups. Multiple logistic regression analyses determined that a single c ourse of betamethasone was independently associated with reductions in the frequencies of both respiratory distress syndrome (odds ratio, 0.16; 95% co nfidence interval, 0.1-0.4) and grade III/IV intraventricular hemorrhage (o dds ratio, 0.18; 95% confidence interval, 0.1-0.4). CONCLUSIONS: A single course of betamethasone administered antenatally to p atients with preterm premature rupture of membranes was associated with dec reases in the frequencies of both respiratory distress syndrome and advance d grades of intraventricular hemorrhage without any increase in perinatal i nfectious morbidity.