The use of a calcium antagonist (nifedipine) to suppress preterm labour. Comparison of magnesium sulfate, terbutaline and a placebo for inhibition of preterm labor. A randomized study. A randomised trial of two expectant managements of prelabour rupture of the membranes at 34 to 42 weeks. Prelabour rupture of the membranes at term--no advantage of delaying induction for 24 hours. Ritodrine in oral maintenance of tocolysis after active preterm labor: randomized controlled trial. Sweeping of the membranes versus uterine stimulation by oxytocin in nulliparous women. A randomized controlled trial. Comparison of nifedipine and ritodrine for the treatment of preterm labor. A randomized comparison of nifedipine and ritodrine for suppression of preterm labor. Induction of labor by intracervical prostaglandin gel and oxytocin infusion in primigravid women with unfavorable cervix.
The efficacy of an orally administered calcium antagonist, nifedipine, in suppressing premature uterine activity, was compared with intravenous ritodrine and no treatment. Nifedipine was found to be significantly more effective than ritodrine or withholding therapy, and was almost devoid of side-effects. Magnesium sulfate has been recommended as a safe and effective agent for inhibiting preterm labor. Its reported adequacy as a tocolytic agent, however, has not been substantiated by randomized, controlled trials. To assess the efficacy of magnesium sulfate, we initiated a prospective, randomized study comparing the capabilities of magnesium sulfate, terbutaline and a placebo (5% dextrose in lactated Ringer's solution) for labor inhibition. The study population consisted of 54 patients between 26 and 34 weeks of gestation and in preterm labor. The diagnosis of labor was made if, following hydration, persistent uterine contractions occurred at a frequency of at least three in a ten-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 there were no significant differences between the three treatment groups with regard to capability of delaying delivery at least 48 hours. Also, there were no significant differences between the groups with regard to gestational age at delivery, birth weight and neonatal survival. The fact that delivery occurred in less than 48 hours of approximately one-half the patients under the best of circumstances emphasizes the need for more effective techniques for the inhibition of preterm labor and the need for a better understanding of the mechanisms involved in the initiation of preterm labor. To compare obstetric and perinatal outcome between two different expectant managements in women with prelabour rupture of the membranes (PROM).
                A randomised study.
                One thousand three hundred and eighty-five women with rupture of the membranes at 34 to 42 weeks without contractions.
                Women without contractions 2 h after admission were randomised to early induction the following morning after PROM (early induction group) or induction two days later (late induction group). Women with contractions starting within 2 h after admission were included in the calculations as a short latency group. Digital examinations of the cervix were avoided until onset of active labour. Labour was induced with oxytocin in both groups if no spontaneous contractions occurred or if chorioamnionitis or fetal distress was detected.
                The frequency of spontaneous deliveries, operative deliveries, maternal and neonatal infections.
                In nulliparous women, a higher rate of spontaneous deliveries was found in the late induction group (89%) compared with the early induction group (81%) (P < 0.05). The ventouse extraction rate was 7% and 14% respectively (P < 0.05). A low (2-4%) caesarean section rate was recorded and did not differ between the groups. Endometritis was detected in six women after delivery. Sixty-one children were treated with antibiotics, and no difference could be detected between the groups.
                A higher rate of spontaneous deliveries was found among nulliparous women with prolonged latency as compared with brief latency prior to induction. A protocol of no digital examination before labour was associated with infrequent maternal and fetal morbidity, regardless of latency. We performed a prospective randomized study to compare maternal and fetal outcomes in pregnancies with prelabour rupture of the membranes (PROM) at term with early induction of labour or expectant management, 126 women with singleton pregnancy, cephalic presentation and gestational duration > or = 37 weeks, were randomized either to immediate induction of labour with oxytocin (Group 1) (n=52), or conservative management (Group 2) (n=74). Women who constituted Group 2 were divided into 2 groups. The first group (Group 2A) (n=25) included women in whom spontaneous labour did not begin after a waiting period of 24 hours, in which case labour was induced with oxytocin i.e. expectant management. The second group consisted of women (Group 2B) (n=49) in whom labour began spontaneously within 24 hours. The base Caesarean section rate was significantly higher in Group 2 (28.4%) (p<0.05). The rates of Caesarean section in the Groups 1-2A-2B were 19.2%, 60%, and 12.2%, respectively for nulliparous and parous women together. The rate of fetal distress was significantly higher in Group 2 (p<0.05). For determining maternal outcomes, the other parameters such as clinical chorioamnionitis, fever before or during labour, receiving antibiotics before or during labour, postpartum fever, analgesia, anaesthesia did not differ in Groups 1 and 2. Women in Group 1 went into active labour sooner, had fewer digital vaginal examinations, had a shorter interval between membrane rupture and delivery, and spent less time in the hospital before delivery than those in Group 2 (p<0.05). Babies in Group 2 were more likely to receive antibiotics, and more likely to stay in an intensive care nursery for more than 24 hours, and more likely to receive ventilation after initial resuscitation than those babies in Group 1. For developing apnoea and hypotonia, there was no significant difference between Groups 1 and 2. However, for babies in Group 2A there was a significant difference. We conclude that immediate induction of labour with oxytocin does not increase the risk of Caesarean section, compared with a practice of expectant management. Women at term with prelabour rupture of the membranes should therefore be reassured that immediate induction with oxytocin currently appears to be the best policy with respect to maternal and neonatal morbidity. 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. The aim of this study was to evaluate whether sweeping of the membranes at term could shorten the length of pregnancy and reduce the incidence of postterm pregnancies. We randomly selected 104 nulliparas with uncomplicated pregnancy and gestational age between 281 and 287 days. Our patients were divided into three groups. Group A consisted of 34 women who were subjected to sweeping of the membranes. Uterine stimulation with oxytocin was applied in 35 women (group B), and 35 women (group C) were used as a control group. We had no significant reduction of the time interval from sweeping of the membranes until delivery (1.9 +/- 1.2 days), compared to that of group B (2.1 +/- 0.8 days) as well as that of the control group (2.5 +/- 0.9 days). The incidence of spontaneous labor in patients after sweeping of the membranes was greater (67.6%) when compared with oxytocin-stimulated patients and the control group (p < 0.05). Furthermore, a better Bishop score was noted in patients of group A. No statistically significant difference was noted in the mode of delivery between the groups, but sweeping of the membranes significantly decreased the incidence of postterm pregnancies (p < 0. 05). We concluded that sweeping of the membranes is an effective method for initiating labor in women with a gestational age between 40 and 41 weeks, thus reducing the need for induction.
                Copyright 2000 S. Karger AG, Basel Treatment of preterm labor with beta-sympathomimetics has been questioned because of the many maternal and fetal complications associated with its use. Nifedipine, a calcium antagonist, has been shown to suppress uterine activity in vitro and in vivo. A randomized prospective study was performed to compare the efficacy of nifedipine to ritodrine in the suppression of preterm labor. Data obtained from 42 women, of which 19 were randomized to the ritodrine group and 23 to the nifedipine group, were analyzed. Ritodrine and nifedipine proved to be equally effective in the suppression of preterm labor. However, the nifedipine group had fewer maternal and fetal complications. To compare the efficacy and safety of nifedipine and ritodrine in preventing preterm labor, and to evaluate maternal side effects and neonatal outcome.
                Non-blind, randomized controlled trial
                A randomized trial of 102 pregnant women with gestational ages under 34 weeks, including 24 with twin pregnancies and 45 on betasympathicomimetic drugs, who had regular uterine contractions with either observed cervical changes or preterm rupture of membranes. After stratification women were randomly assigned to receive either ritodrine intravenously or nifedipine orally. Fifty-five women were randomized to the nifedipine group and 47 to the ritodrine group. As expected, both groups were comparable in terms of several entry variables, including mean gestational age, ruptured membranes, treatment with tocolytic drugs, cervical examination, contraction frequency, age, and twin gestation. Delivery of women in the nifedipine group was delayed for 48 h, 7 days, and until 34 weeks gestation in 33 (60%), 26 (47%) and 21(38%) cases, respectively, compared with 31 (66%), 21(45%) and 11(23%) women in the ritodrine group (no significant difference). Maternal side effects were significantly less common in the nifedipine group than in the ritodrine group, however after 7 days of therapy there was no difference between the two groups. Neonatal outcome was similar in the two groups, with four neonatal deaths in the nifedipine and five in the ritodrine group.
                Nifedipine seems to be as effective as ritodrine in the treatment of preterm labor and is associated with less frequent side effects. The rate of Cesarean Section for failed induction of labor and maternal and fetal compilations are high when labor is induced in a nulliparas women with an unripe cervix by amniotomy and oxytocin infusion. Prostaglandins (PG) in different forms have been used for ripening the cervix with an aim of reducing these problems. A prospective randomized trial was performed on one hundred primigravid women between 37 and 42 weeks of gestation with singleton pregnancy, cephalic presentation and unfavorable cervix (Modified Bishop Score < or = 5) in the department of Obstetrics & Gynaecology of Institute of Postgraduate Medicine & Research from 1st May 1996 to 30th April 1997. In this study the efficiency of prostaglandin E2 intracervical (PGE2 IC) gel in induction of labor in a group of primigravid women with unripe cervix was assessed and compared with another group with similar characteristics using oxytocin infusion and artificial rupture of membrane (ARM). The Modified Bishop Score (MBS), interval between IOL and onset of labor and the duration of labor after insertion of PGE2 gel was significantly different from those of oxytocin infusion group. But the Apgar Score at 1 & 5 min had shown no statistically significant difference. Any significant difference could also not be detected in the mode of delivery between the two induction group. The proportion of emergency Cesarean Section (CS) was high in the oxytocin infusion group than that of in the prostaglandin group. There was also no significant difference regarding the acceptability of both the induction methods.
There is insufficient information on which to base decisions about the role of COX inhibition for women in preterm labour. Further well designed trials are needed.
[Note: The 11 citations in the awaiting classification section of the review may alter the conclusions of the review once assessed.]