THE CLINICAL EFFICACY OF ORAL TOCOLYTIC THERAPY

OBJECTIVE: Our purpose was to determine whether maintenance oral tocol ytic therapy after preterm labor stabilization decreases uterine activ ity reduces the rate of recurrent preterm labor and subsequent preterm birth, or improves neonatal outcome. STUDY DESIGN: Women with documen ted idiopathic preterm labor stabilized with acute tocolytic therapy w ere randomized to three groups: placebo, terbutaline 5 mg, or magnesiu m chloride 128 mg, all given orally every 4 hours, Patients and provid ers were blinded to group assignment. Ail subjects were enrolled in a comprehensive system of preterm birth prevention that included preterm labor education, weekly clinic visits, home uterine contraction asses sment, daily phone contact, and 24-hour perinatal nurse access. RESULT S: Of the 248 patients who were randomized, 39 were delivered before d ischarge and 4 were lost to follow-up, leaving 205 for final analysis: 68 placebo, 72 terbutaline, and 65 magnesium. The terbutaline group h ad significantly more side effects than the placebo group did. All gro ups had otherwise similar perinatal outcomes when confounding variable s were controlled for. Overall, the three groups had a preterm birth r ate <37 weeks of 55.6% delivery, <34 weeks of 15.6%, a 20.4% rate of n ewborn intensive care unit admission, and a mean neonatal length of st ay of 6.3 days. CONCLUSIONS: Maintenance oral tocolytic therapy did no t decrease uterine activity reduce the rate of recurrent preterm labor or preterm birth, or improve perinatal outcome, Overall improvement i n perinatal outcome may be achieved with a comprehensive program of pr eterm birth prevention without the use of maintenance oral tocolytic t herapy.