Terbutaline pump maintenance therapy for prevention of preterm delivery: a double-blind trial. A placebo-controlled randomized trial of the terbutaline pump for prevention of preterm delivery. Randomized comparison of oral terbutaline and ritodrine for preventing recurrent preterm labor. Oral terbutaline in the outpatient management of preterm labor. Oral terbutaline after parenteral tocolysis: a randomized, double-blind, placebo-controlled trial. The clinical efficacy of oral tocolytic therapy. Management options in women with preterm uterine contractions: a randomized clinical trial. Ritodrine in oral maintenance of tocolysis after active preterm labor: randomized controlled trial. Terbutaline sulfate in the prevention of recurrence of premature labor.
This study's aim was to determine whether maintenance therapy with terbutaline administered by pump prolongs gestation in women after treatment with intravenous magnesium sulfate tocolysis for suspected preterm labor.
                Consenting women with a singleton gestation and intact membranes who had uterine contractions and >1 cm cervical dilation, 80% effacement, or progressive cervical change and whose contractions were successfully arrested with intravenous magnesium were randomly assigned to receive either terbutaline or normal saline solution placebo by subcutaneous infusion pump. Pump therapy was administered with a standardized protocol. Pump therapy was discontinued and parenteral magnesium was resumed if recurrent preterm labor developed while women were on the therapeutic regimen at <34 weeks' gestation and no contraindication for tocolysis existed. If recurrent labor was arrested, pump therapy was restarted according to the original treatment group. A sample size of 48 women was required to detect a 2-week intergroup difference in mean time to delivery. Analyses were based on intent to treat.
                Fifty-two women received terbutaline (n = 24) or placebo (n = 28). At random assignment the groups were similar with respect to age, race, parity, previous preterm delivery, gestational age, and cervical examination. Overall there was a 1-day difference in mean time to delivery between the groups (terbutaline 29 +/- 22 days and placebo 28 +/- 23 days, P = .78). There were no differences in the rates of preterm delivery at <34 and <37 weeks' gestation. Neonatal outcomes were similar.
                Maintenance terbutaline therapy administered by pump does not prolong gestation in women successfully treated for suspected preterm labor. To determine the efficacy of the terbutaline pump for the prevention of preterm delivery, patients in preterm labor defined by progressive cervical change underwent intravenous magnesium sulfate tocolysis (with or without oral indomethacin, as necessary), and once labor was arrested, were randomized to one of three treatment arms: terbutaline by pump, saline by pump (blinded), or oral terbutaline. If recurrent preterm labor occurred despite maximization of therapy, the treatment arm was determined and therapy was changed; saline pump and oral terbutaline were switched to terbutaline pump, terbutaline pump was switched to oral terbutaline. Patients who continued to labor were readmitted for aggressive intravenous therapy. Women randomized to the terbutaline pump (n = 15), saline pump (n = 12), and oral terbutaline (n = 15) groups were similar in terms of gravidity, parity, days of tocolysis before study entry, gestational age at entry, and cervical dilatation at entry. The mean gestational age at delivery was the same in all three groups (35 weeks), as were neonatal outcomes. Terbutaline by pump, saline by pump, and oral terbutaline appear equivalent for the prevention of preterm delivery. The terbutaline pump should remain experimental. We compared oral ritodrine and terbutaline for the prevention of recurrent preterm labor. Women between 20 and 35 weeks' gestation who successfully completed a course of intravenous tocolysis were eligible for inclusion. One hundred two patients were randomized to oral ritodrine (20 mg every four hours) or oral terbutaline (5 mg every four hours). The groups showed no significant differences with respect to recognized risk factors for preterm labor or prognostic factors for the failure of tocolysis. Initial treatment failures occurred more frequently in the ritodrine group (nine vs. two, P = .0527). There were no statistically significant differences in the treatment results or frequency of side effects. We conclude that ritodrine appears to be less effective than terbutaline upon the initiation of oral therapy and that oral ritodrine and terbutaline are equivalent in safety and efficacy when used on a long-term basis for preventing recurrent preterm labor. Our purpose was to prove our hypothesis that once preterm uterine contractions and/or labor is controlled with intravenous tocolysis, oral terbutaline, as a maintenance drug, does not prolong pregnancy.
                Before discharge, 184 patients between 24 and 35 completed weeks' gestation were prospectively randomized to continued bed rest either with or without oral terbutaline. Assignment was made with stratification into four groups: group 1, those patients with a Bishop score > or = 5 with oral terbutaline (n = 50); group 2, those with a Bishop score > or = 5 without oral terbutaline (n = 53); group 3, those with a Bishop score < 5 with oral terbutaline (n = 41); group 4, those with a Bishop score < 5 without oral terbutaline (n = 40). Oral terbutaline was discontinued at 37 completed weeks.
                No statistically significant differences were found in the number of readmissions, the number of unscheduled hospital visits, and the neonatal outcomes among the four groups. The gestational age at delivery and percent of deliveries at > or = 37 weeks were not significantly different when group 1 was compared with group 2 and group 3 was compared with group 4.
                Oral terbutaline maintenance does not improve pregnancy outcome in patients who have had initial successful intravenous tocolysis. Our purpose was to determine whether oral terbutaline, used after successful intravenous tocolysis, will prolong pregnancy and prevent recurrent preterm labor.
                After successful intravenous tocolysis, 203 women with preterm labor at 24 weeks' to 34 weeks 6 days' gestation were randomized to terbutaline (5 mg orally, every 4 hours) or placebo until 37 weeks' gestation. Women with recurrent preterm labor were treated with intravenous magnesium sulfate; if tocolysis was successful, they continued with the initial study medication. The primary outcome was the percentage delivered of their infants within 1 week of beginning oral tocolytic therapy. Latency, recurrent preterm labor, and maternal and neonatal outcomes were also assessed.
                Pregnancy outcome data were available in 200 women. There were no differences seen between the two groups in the incidence of delivery at 1 week (18% vs 24%, 95% confidence interval 0.44 to 1.29). In addition, there were no differences regarding median latency, mean gestational age at delivery, or the incidence of recurrent preterm labor (20% vs 16%, 95% confidence interval 0.64 to 2.71). Post hoc evaluation of 96 women enrolled before 32 weeks' gestation suggested pregnancy prolongation with maintenance oral terbutaline (p < 0.01).
                Maintenance oral terbutaline therapy initiated at 24 weeks' to 34 weeks 6 days' gestation after successful parenteral tocolysis is not associated with pregnancy prolongation or a reduction in the incidence of recurrent preterm labor. 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.
                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.
                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.
                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. Our purpose was to evaluate three management strategies and to assess pregnancy outcomes in women with preterm uterine contractions.
                Consenting women seen in our hospital triage area with preterm uterine contractions were randomly assigned to observation alone, intravenous hydration, or one dose of subcutaneous terbutaline sulfate (0.25 mg). Eligible women had a singleton gestation between 20 and 34 weeks, intact membranes, more than three contractions in 30 minutes, and a cervical dilation < or = 1 cm and effacement < 80%. Women who had progressive cervical change at < 34 weeks were treated with intravenous tocolysis. Women with recurrent preterm uterine activity remained in their assigned group during subsequent triage visits.
                One hundred seventy-nine women were randomized: observation (56), hydration (62), and terbutaline (61). Women in these three groups were similar with respect to maternal age, race, parity, prior preterm births, gestational age at randomization, contraction frequency, and mean cervical dilatation. There were no intergroup differences in the mean days to delivery, the number of repeat triage visits, the incidence of preterm labor at < 34 weeks, or the frequency of preterm deliveries at < 34 weeks and < 37 weeks. Women assigned to terbutaline had contractions stopped and were discharged earlier (terbutaline 4.1 +/- 5.1 hours, observation 5.2 +/- 5.3 hours, hydration 6.0 +/- 5.7 hours; p = 0.006). No complications of therapy were observed.
                The use of intravenous hydration in the management of preterm contractions was of no benefit. The use of one dose of subcutaneous terbutaline resulted in the shortest length of triage stay but did not affect pregnancy outcome. To assess the efficacy of oral ritodrine in the form of sustained-release capsules for maintenance of uterine quiescence after successful treatment of threatened preterm labor.
                We randomized 120 women with singleton pregnancy who were successfully treated for threatened preterm labor before 34 completed weeks to receive either maintenance tocolysis with two 40 mg ritodrine sustained release capsules three times a day (study group, n=62) or no treatment (control group, n=58) for three days. The primary outcome measure was the recurrent episode of threatened preterm labor within 72 hours, which was defined as regular palpable uterine contractions and change in cervical effacement or cervical dilatation on clinical examination. Secondary outcome measures included the incidence of preterm birth, neonatal adverse outcomes, and maternal side effects.
                There was no difference in the frequency of recurrent episodes of threatened preterm labor requiring another course of intravenous treatment between the study (8/62) and control (6/58) group of women (P=0.879). No differences were found between the study and control groups in any of the predefined secondary outcome measures, ie, delivery before 37 weeks (13/62 vs 7/58, respectively; P=0.288), delivery before 34 weeks (3/62 vs 1/58, respectively; P=0.682) and birth weight (3037-/+573 g vs 3223-/+423 g, respectively, P=0.862). There were more reported maternal side effects in the study group than in control group (47/62 vs 23/58, respectively; P(<0.001).
                Additional maintenance ritodrine therapy was unnecessary in women with singleton pregnancy who had an episode of threatened preterm labor successfully treated with intravenous tocolytic therapy.
                ClinicalTrials.gov Identifier: NCT00290173. Forty-six patients in premature labor were initially successfully treated with ethanol infusion. Twenty-three of these patients were then given prolonged oral terbutaline sulfate therapy until 38 weeks' gestation, and the remaining 23 patients were given placebo. The treated group gained significantly more time in gestation than the placebo group (P < .05), although the placebo group started with a higher Bishop score. In addition, idiopathic respiratory distress syndrome was seen significantly less often in the treated group. There was no perinatal mortality in either group.
Terbutaline pump maintenance therapy has not been shown to decrease the risk of preterm birth by prolonging pregnancy. Furthermore, the lack of information on the safety of the therapy, as well as its substantial expense, argues against its role in the management of arrested preterm labor. Future use should only be in the context of well-conducted, adequately powered randomized controlled trials.
 [Note: The two citations in the awaiting classification section of the review may alter the conclusions of the review once assessed.]