The clinical efficacy of oral tocolytic therapy. Progesterone for maintenance tocolytic therapy after threatened preterm labour: a randomised controlled trial. Randomized trial of antibiotics in addition to tocolytic therapy to treat preterm labor. [Tocolytic therapy with magnesium sulfate and terbutaline for inhibition of premature 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. Women with preterm labour that is arrested with tocolytic therapy are at increased risk of recurrent preterm labour. The efficacy of maintenance tocolytic therapy after successful arrest of preterm labour remains controversial.
                The purpose of this study was to determine whether supplementation of vaginal progesterone after inhibition of preterm labour is associated with an increased latency period and a decreased recurrent of preterm labour.
                This trial was conducted in 70 women who presented with symptoms of threatened preterm labour, who after arrest of uterine activity were then randomised to progesterone therapy or no treatment. Treatment group received progesterone suppository (400 mg) daily until delivery and control group received no treatment.
                Longer mean latency until delivery (36/11 +/- 17/9 vs 24/52 +/- 27/2) (mean + standard deviation) days; respiratory distress syndrome 4 (10.8%) vs 12 (36.4%) P = 0.021; low birthweight 10 (27%) vs 17 (51.5%) P = 0.04; and birthweight (3101.54 +/- 587.9 g vs r 2609.39 +/- 662.9 g, P = 0.002), were significantly different between the two groups. No significant differences were found between recurrent preterm labour 13 (35.1%) vs 19 (57.6%), P = 0.092; admission to intensive care unit 9 (24.3%) vs 13 (39.4%), P= 0.205 ; and neonatal sepsis 2 (5.4%) vs 6 (18.2%) P = 0.136, for the progesterone and control groups, respectively.
                The use of vaginal progesterone suppository after successful parenteral tocolysis associated with a longer latency preceding delivery but failed to reduce the incidence of readmission for preterm labour. The objective of this study was to assess whether antibiotic therapy plus tocolysis given to women in preterm labor would prolong pregnancy compared with tocolysis alone.
                A randomized, double-blind trial of intravenous mezlocillin and oral erythromycin therapy vs. placebo was used in addition to tocolysis among women in preterm labor < or =34 weeks gestation with intact membranes. Amniocentesis was performed, and chorioamnionic membranes were examined histologically and cultured for microorganisms after delivery.
                Clinical characteristics including gestational age at enrollment, frequency of contractions, cervical Bishop's score, and white blood cell count on admission were similar in the 2 groups. Antibiotic therapy was well tolerated. No significant differences in the interval to delivery, birth weight, and neonatal outcomes were observed between the 2 groups. Women in the antibiotic group had a significantly lower incidence of postpartum infections compared with women in the placebo group. Patients with evidence of upper genital tract infection in either group had a significantly shorter interval to delivery, lower gestational age at delivery, lower mean birth weight, and increased neonatal hospitalization time.
                Lack of an antibiotic effect on the gestational age at delivery may be due to the low prevalence of upper genital tract infection among unselected women in preterm labor, to advanced preterm labor unresponsive to antibiotic therapy, or to an inability of antibiotics given alone to inhibit the cytokine response. Further work is needed to identify markers of upper genital tract infection among women in preterm labor and to evaluate other potential therapeutic interventions. Magnesium sulfate has been recommended as a safe and effective tocolytic agent. However has not been substantiated by randomized, controlled trials. To assess the efficacy of magnesium sulfate, we initiated prospective randomized study competing the capabilities of magnesium sulfate and terbutaline for labor inhibition. The study population consisted of 30 patients (15 patients with terbutaline and 15 patients with magnesium sulfate) between 28 and 36 weeks of gestation and in preterm labor. One patient in terbutaline group was excluded of the study because we found a severe fetal distress. The diagnosis of labor was made if, persistent uterine contractions occurred at a frequency of at last three in a team-minute period and cervical examination suggested active labor. Success was defined as postponement of delivery for at least 48 hours after initiation of therapy. Despite a trend toward increased efficacy in the terbutaline group (tocolytic Bishop grade and its success) there were no significant differences between the two treatment groups with regard to capability of delaying delivery at least 48 hours. Although there were significant differences for terbutaline regard the tocolysis time. For all these reasons, the efficacy between both groups of treatment is similar, and in a future cases, will be necessary to choose the better agent for every case to study.
Currently, there is insufficient evidence to advocate progestational agents as a tocolytic agents for women presenting with preterm labour.