The clinical efficacy of oral tocolytic therapy.
OBJECTIVE
Our purpose was to determine whether maintenance oral tocolytic therapy after preterm labor stabilization decreases uterine activity, reduces the rate of recurrent preterm labor and subsequent preterm birth, or improves neonatal outcome.


METHODS
Women with documented idiopathic preterm labor stabilized with acute tocolytic therapy were randomized to three groups: placebo, terbutaline 5 mg, or magnesium chloride 128 mg, all given orally every 4 hours. Patients and providers were blinded to group assignment. All subjects were enrolled in a comprehensive system of preterm birth prevention that included preterm labor education, weekly clinic visits, home uterine contraction assessment, daily phone contact, and 24-hour perinatal nurse access.


RESULTS
Of the 248 patients who were randomized, 39 were delivered before discharge and 4 were lost to follow-up, leaving 205 for final analysis: 68 placebo, 72 terbutaline, and 65 magnesium. The terbutaline group had significantly more side effects than the placebo group did. All groups had otherwise similar perinatal outcomes when confounding variables were controlled for. Overall, the three groups had a preterm birth rate < 37 weeks of 55.6% delivery, < 34 weeks of 15.6%, a 20.4% rate of newborn intensive care unit admission, and a mean neonatal length of stay of 6.3 days.


CONCLUSIONS
Maintenance oral tocolytic therapy did not decrease uterine activity, reduce the rate of recurrent preterm labor or preterm birth, or improve perinatal outcome. Overall improvement in perinatal outcome may be achieved with a comprehensive program of preterm birth prevention without the use of maintenance oral tocolytic therapy.
Rust
O A
OA
Department of Obstetrics and Gynecology, University of Mississippi Medical Center, Jackson 39216-4505, USA.
Bofill
J A
JA
Arriola
R M
RM
Andrew
M E
ME
Morrison
J C
JC
D000284:Administration, Oral; D001723:Birth Rate; D004311:Double-Blind Method; D005260:Female; D006760:Hospitalization; D006801:Humans; D007231:Infant, Newborn; D007234:Infant, Premature; D015931:Intensive Care, Neonatal; D015636:Magnesium Chloride / Q000008:administration & dosage / Q000627:therapeutic use; D011247:Pregnancy; D011256:Pregnancy Outcome; D013726:Terbutaline / Q000008:administration & dosage / Q000627:therapeutic use; D015149:Tocolytic Agents / Q000008:administration & dosage* / Q000627:therapeutic use; D017211:Treatment Failure; D016896:Treatment Outcome; D014590:Uterine Contraction / Q000187:drug effects; D018590:Uterine Monitoring
D015149:Tocolytic Agents; D015636:Magnesium Chloride; D013726:Terbutaline