Objective: This study was undertaken to determine the effect of antenatal betamethasone administration on the incidences of respiratory distress syndrome, 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 with singleton pregnancies who were delivered between 24 and 32 weeks' gestation 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 >2 doses of betamethasone were excluded. All patients received broad-spectrum prophylactic antibiotics. Data were analyzed with the Student t test, the chi(2) test, and the Fisher exact test. Multiple logistic regression analyses incorporated multiple variables considered risk factors for respiratory distress syndrome and intraventricular hemorrhage. P <.05 for all 2-tailed tests was considered significant.
Results: A total of 362 patients were included, with 203 in the control group and 159 in the single-course group. Patients in these groups were delivered at 31.0 +/- 3.0 and 30.2 +/- 2.7 (mean +/- SD) weeks' gestation, respectively. The groups were similar with respect to selected demographic characteristics, latency until delivery, mode of delivery, birth weight, and maternal group B streptococcal colonization status. Univariate analysis demonstrated significant decreases in the frequencies of both respiratory distress syndrome (odds ratio, 0.31; 95% confidence interval, 0.2-0.5) and grade III/IV intraventricular hemorrhage (odds ratio, 0.14; 95% confidence interval, 0.1-0.6) in the single-course group. The frequencies of early neonatal sepsis, chorioamnionitis, endometritis, and neonatal death were similar between groups. Multiple logistic regression analyses determined that a single course of betamethasone was independently associated with reductions in the frequencies of both respiratory distress syndrome (odds ratio, 0.16; 95% confidence interval, 0.1-0.4) and grade III/IV intraventricular hemorrhage (odds ratio, 0.18; 95% confidence interval, 0.1-0.4).
Conclusions: A single course of betamethasone administered antenatally to patients with preterm premature rupture of membranes was associated with decreases in the frequencies of both respiratory distress syndrome and advanced grades of intraventricular hemorrhage without any increase in perinatal infectious morbidity.