Uterine Tachysystole Research Articles

Randomized trial of isosorbide mononitrate versus misoprostol for cervical ripening at term

Objectives: To assess the adverse effects of isosorbide mononitrate (IMN) compared with misoprostol for cervical ripening at term. Methods: One hundred and seven women with term pregnancies referred for induction of labor with Bishop scores of 6 or less were randomly allocated to receive either a 40-mg IMN tablet vaginally ( n=55) or 50 μg misoprostol vaginally ( n=52) every 6 h for a maximum of three doses. They were sent to the labor ward for amniotomy or oxytocin if either their Bishop scores were more than 6 or their cervices were not ripe 24 h after the treatment. Adverse effects, progress, and outcomes of labor were assessed. Results: Isosorbide mononitrate was associated with fewer adverse effects especially uterine tachysystole (0 vs. 19.2%, P<0.01) and hyperstimulation (0 vs. 15.4%, P<0.01). The time from start of medication to vaginal delivery in IMN group was significantly longer (25.6±6.1 vs. 14±6.9 h, P<0.01). Oxytocin was needed in 51 women (92%) of the isosorbide mononitrate group and six women (11%) of the misoprostol group ( P<0.001). The cesarean rate was not significantly different between the groups, but the major indications were different: dystocia (45%) in the IMN group vs. persistent non-reassuring fetal heart rate pattern (56%) in the misoprostol group. Conclusions: Cervical ripening with IMN resulted in fewer adverse effects, but was less effective than misoprostol.

Medical management of late intrauterine death using a combination of mifepristone and misoprostol.

To assess the efficacy and safety of mifepristone in combination with misoprostol in the management of late fetal death. Observational study. Aberdeen Maternity Hospital, Aberdeen. A consecutive series of 96 women with intrauterine death after 24 weeks of gestation were studied. Each woman received a single dose of 200 mg mifepristone orally, following which a 24-48 hour interval was recommended before administration of misoprostol. For gestations of 24-34 weeks, 200 microg of intravaginal misoprostol was administered, followed by four oral doses of 200 microg at three hourly intervals. Gestations over 34 weeks were given a similar regimen but a reduced dose of 100 microg misoprostol. The average induction to delivery interval was 8.5 hours. Ninety-five women (98.9%) were delivered within 72 hours of administration of first dose of misoprostol, with 66.7%, 87.5%, 92.7% and 95.8% women delivering within 12, 24, 36 and 48 hours, respectively. No significant correlation was found between mean induction to delivery interval and maternal age, parity, Bishop's score, birthweight and mifepristone/ misoprostol interval. The induction to delivery interval was shorter with increasing gestation (P = 0.04). Mild side effects were noted in eight (8.3%) women. Three (3.1%) women had treatment for presumed or proven pelvic sepsis. No cases of uterine tachysystole, haemorrhage or coagulopathy were recorded. The combination of mifepristone and misoprostol for induction of labour following late fetal death is an effective and safe regimen. The induction to delivery interval with this regimen appears shorter than studies using mifepristone or misoprostol.

Does nifedipine prevent the tachysystole associated with misoprostol induction?

Objective: To determine the efficacy of oral nifedipine as prophylaxis against uterine tachysystole associated with misoprostol induction of labor. Methods: A total of 116 patients undergoing induction with term, singleton pregnancies were enrolled. All patients received 50 μg misoprostol intravaginally every 4 h. Patients were randomly assigned also to receive nifedipine 10 mg orally every 4 h, or no prophylaxis. The primary outcome variable was the incidence of 12 or more contractions in any 20-min interval. Results: Data on 106 patients were available for analysis. There were 55 subjects in the misoprostol-nifedipine group and 51 controls. Nifedipine did not diminish the incidence of tachysystole when added to misoprostol (42% vs. 45% without nifedipine; p = 0.7). Conclusion:Prophylactic oral nifedipine was not shown to decrease the uterine tachysystole associated with vaginal misoprostol induction at a 50-μg dose.

Medical management of late intrauterine death using a combination of mifepristone and misoprostol

Objective To assess the efficacy and safety of mifepristone in combination with misoprostol in the management of late fetal death. Design Observational study. Setting Aberdeen Maternity Hospital, Aberdeen. Methods A consecutive series of 96 women with intrauterine death after 24 weeks of gestation were studied. Each woman received a single dose of 200mg mifepristone orally, following which a 24–48 hour interval was recommended before administration of misoprostol. For gestations of 24–34 weeks, 200μg of intravaginal misoprostol was administered, followed by four oral doses of 200μg at three hourly intervals. Gestations over 34 weeks were given a similar regimen but a reduced dose of 100μg misoprostol. Results The average induction to delivery interval was 8.5 hours. Ninety-five women (98.9%) were delivered within 72 hours of administration of first dose of misoprostol, with 66.7%, 87.5%, 92.7% and 95.8% women delivering within 12, 24, 36 and 48 hours, respectively. No significant correlation was found between mean induction to delivery interval and maternal age, parity, Bishop's score, birthweight and mifepristone/misoprostol interval. The induction to delivery interval was shorter with increasing gestation ( P = 0.04). Mild side effects were noted in eight (8.3%) women. Three (3.1%) women had treatment for presumed or proven pelvic sepsis. No cases of uterine tachysystole, haemorrhage or coagulopathy were recorded. Conclusion The combination of mifepristone and misoprostol for induction of labour following late fetal death is an effective and safe regimen. The induction to delivery interval with this regimen appears shorter than studies using mifepristone or misoprostol.

Does nifedipine prevent the tachysystole associated with misoprostol induction?

Objective: To determine the efficacy of oral nifedipine as prophylaxis against uterine tachysystole associated with misoprostol induction of labor.Methods: A total of 116 patients undergoinginduction with term, singleton pregnancies were enrolled. All patients received 50 μg misoprostol intravaginally every 4 h. Patients were randomly assigned also to receive nifedipine 10 mg orally every4 h, or no prophylaxis. The primary outcome variable was the incidence of 12 or more contractions in any 20-min interval.Results: Data on 106 patients were available for analysis. There were55 subjects in the misoprostol-nifedipine group and 51 controls. Nifedipine did not diminish the incidence of tachysystole when added to misoprostol (42% vs. 45% without nifedipine; p = 0.7).Conclusion:Prophylactic oral nifedipine was not shown to decrease the uterine tachysystole associated with vaginal misoprostol induction at a 50-μg dose.

A comparison of various routes and dosages of misoprostol for cervical ripening and the induction of labor

Objective: The purpose of this study was to compare the efficacy of different routes of misoprostol administration for cervical ripening and the induction of labor. Study Design: Three hundred thirty women at ≥32 weeks gestation with a Bishop score ≤6 and an indication for induction were randomized to 1 of 3 double-blinded groups: (1) 25 μg orally administered misoprostol plus 25 μg vaginally administered misoprostol, (2) orally administered placebo plus 25 μg vaginally administered misoprostol, or (3) 25 μg orally administered misoprostol plus vaginally administered placebo. Doses were repeated every 4 hours until onset of labor or a maximum of 12 doses were given. The primary outcome of the trial was vaginal delivery within 24 hours of the initiation of induction. Secondary outcomes were the time from induction to delivery, need for oxytocin augmentation, mode of delivery, frequency of side effects, and neonatal and maternal outcome. Analysis of variance, chi-square test, and logistic regression were used for analysis. Results: There were no significant differences in maternal characteristics or indications for induction. The percentage of women who achieved vaginal delivery within 24 hours was highest in the vaginally administered misoprostol group: 67% compared with 53% in the oral-plus-vaginal group (P <.05) and 36% in the oral group (P <.05). The median time to vaginal delivery was shorter in the vaginal and oral-plus-vaginal misoprostol groups, 13.5 hours and 14.3 hours, respectively, when compared with 23.9 hours in the oral group (P <.05). The rate of cesarean delivery was lowest in the vaginal misoprostol group (17% compared with 30% in the oral-plus-vaginal group and 32% in the oral group; P <.05). Uterine tachysystole occurred least frequently in the oral misoprostol group (10% compared with 32% in the vaginal group and 34% in the oral-plus-vaginal group; P <.05). Uterine hyperstimulation also occurred least frequently in the oral misopro-stol group (4% compared with 15% in the vaginal group and 22% in the oral-plus-vaginal group; P <.05). Conclusion: At the doses studied, induction of labor with vaginally administered misoprostol is more efficacious than either oral-plus-vaginal or oral-only route of administration. (Am J Obstet Gynecol 2001;185: 911-5.)

Induction of labour with misoprostol – a prostaglandin E 1 analogue

The purpose of our study was to compare the safety and efficacy of intravaginal misoprostol versus existing hospital protocol of intraccrvical dinoprostone and oxytocin for cervical ripening and induction of labour. 200 patients with indication for induction of labour were randomly assigned to receive either intravaginal misoprostol or dinoprostone/oxytocin combination. In first group twenty five micrograms of misoprostol was placed intravaginally every 6 hours till the patient reached active stage of labour. In second group dinoprostone gel 0.5 mg was placed in the endocervix at night and oxytocin induction was started in the early morning. The average interval from start to induction of vaginal delivery was shorter in misoprostol group (1315±811 minutes) compared to dinoprostone/oxytocin group (1512±712 minutes) (p < 0.01). There was no significant difference in route of delivery. 18% of misoprostol treated patients and 23% of dinoprostone/oxytocin treated patients required Caesarean section. Complications such as uterine tachysystole were significantly higher in misoprostol group (p < 0.01) but it was not associated with increased incidence of uterine hyperstimulation. Perinatal outcome was similar in both groups.

Randomized Comparison of Glyceryl Trinitrate and Prostaglandin E2 for Cervical Ripening at Term

In Brief Objective To estimate the adverse effects of glyceryl trinitrate compared with prostaglandin (PG) E2 vaginal tablet for cervical ripening in term pregnancy. Methods One hundred ten women with term pregnancies referred for induction of labor with Bishop scores of 6 or less were randomly assigned to receive a 500-μg glyceryl trinitrate tablet vaginally (n = 54) or a 3-mg PGE2 tablet vaginally (n = 56), every 6 hours for maximum of two doses. Subjects were sent to the labor ward for amniotomy or oxytocin if their Bishop scores were more than 6 or their cervices were not ripe 24 hours after treatment. Adverse effects, changes in the Bishop scores, progress, and outcomes of labor were assessed. Results Glyceryl trinitrate was associated with fewer episodes of uterine tachysystole (0% versus 9%; P = .02). The median Bishop score after 12 hours was lower in women given glyceryl trinitrate compared with those given PGE2. Adverse effects, including headache and palpitations, were more frequent with glyceryl trinitrate than with PGE2. The cesarean rate was not significantly different between groups. Conclusion Cervical ripening with glyceryl trinitrate resulted in fewer episodes of tachysystole, but there were significantly more minor side effects. It can be used for cervical ripening at term, but it was not as effective as PGE2. Glyceryl trinitrate for cervical ripening caused fewer tachysystoles but was less effective than prostaglandin E2.

Randomized comparison of glyceryl trinitrate and prostaglandin E2 for cervical ripening at term

Objective: To estimate the adverse effects of glyceryl trinitrate compared with prostaglandin (PG) E2 vaginal tablet for cervical ripening in term pregnancy. Methods: One hundred ten women with term pregnancies referred for induction of labor with Bishop scores of 6 or less were randomly assigned to receive a 500-μg glyceryl trinitrate tablet vaginally ( n = 54) or a 3-mg PGE2 tablet vaginally ( n = 56), every 6 hours for maximum of two doses. Subjects were sent to the labor ward for amniotomy or oxytocin if their Bishop scores were more than 6 or their cervices were not ripe 24 hours after treatment. Adverse effects, changes in the Bishop scores, progress, and outcomes of labor were assessed. Results: Glyceryl trinitrate was associated with fewer episodes of uterine tachysystole (0% versus 9%; P = .02). The median Bishop score after 12 hours was lower in women given glyceryl trinitrate compared with those given PGE2. Adverse effects, including headache and palpitations, were more frequent with glyceryl trinitrate than with PGE2. The cesarean rate was not significantly different between groups. Conclusion: Cervical ripening with glyceryl trinitrate resulted in fewer episodes of tachysystole, but there were significantly more minor side effects. It can be used for cervical ripening at term, but it was not as effective as PGE2.

A randomized comparison of oral and intravaginal misoprostol for labor induction

Objective: To compare oral misoprostol (100 μg) to vaginal misoprostol (25 μg) for cervical ripening and labor induction. Methods: Two hundred thirty-six women with medical or obstetric indications for labor induction and undilated, uneffaced cervices were assigned randomly to receive 100 μg of oral or 25 μg of vaginal misoprostol every 4 hours for 24 hours. Intravenous oxytocin was then given using a standardized protocol. We anticipated that 31% of women treated orally and 50% of women treated vaginally would deliver vaginally within 24 hours of starting labor induction. Results: Among 234 subjects, 121 received oral and 113 received vaginal misoprostol. The mean (± standard deviation [SD]) interval from start of induction to delivery was 1240 ± 845 minutes for orally treated women and 1381 ± 802 minutes for vaginally treated women ( P = .06, log-transformed data). More orally treated women delivered vaginally in 24 hours than vaginally treated women (74 versus 54, P = .14, relative risk [RR] 1.14, 95% confidence interval [CI] 0.92, 1.40). One hundred six women (87.6%) who received oral misoprostol delivered vaginally, compared with 88 women (77.9%) who received vaginal misoprostol ( P = .07). Oxytocin was given to 60 (49.6%) orally treated and 59 (52.2%) vaginally treated subjects ( P = .69). More women in the oral group had tachysystole, nine compared with two ( P = .06), hypertonus, and hyperstimulation. Frequencies of intrapartum complications and birth outcomes were similar between groups. Conclusion: Oral misoprostol 100 μg and vaginal misoprostol 25 μg were similarly effective for cervical ripening and labor induction. Oral administration was associated with trends toward higher likelihood of vaginal delivery and more uterine tachysystole.

Labor induction with prostaglandin E 1 misoprostol compared with dinoprostone vaginal insert: A randomized trial

Objective: To compare the safety, efficacy, and costs of intravaginal misoprostol versus dinoprostone vaginal inserts for cervical ripening and labor induction. Methods: Two hundred twenty-three labor induction patients were assigned randomly to one of two treatment groups: 1) intravaginal misoprostol or 2) dinoprostone vaginal inserts. Fifty micrograms of misoprostol were placed in the posterior vaginal fornix every 3 hours for a maximum period of 24 hours. Ten milligrams of dinoprostone was administered in a single application as a vaginal insert for 12 hours. Results: Among 223 patients evaluated, 108 were allocated to the misoprostol group and 115 to the dinoprostone group. The median interval from induction to vaginal delivery was significantly shorter in the misoprostol group: 698 (range 395–1053) versus 1041 (range 792–1531) minutes ( P < .001). Vaginal delivery within 12 hours of ripening occurred in 40.7% of patients who received misoprostol compared with 19.1% for those receiving dinoprostone ( P < .001); no significant difference between the groups was noted for vaginal delivery within 24 hours. Uterine tachysystole occurred more frequently in patients in the misoprostol group (21.3%) than in the dinoprostone group (7.0%) ( P = .004). Nevertheless, no statistically significant differences were noted between the groups with respect to intrapartum complications, including uterine hyperstimulation, mode of delivery, and neonatal or maternal adverse outcomes. The average cost per patient for misoprostol treatment was $85 compared with $606 for treatment with the vaginal insert. Conclusion: Intravaginal misoprostol and the dinoprosone vaginal insert appear to be safe agents for cervical ripening and labor induction. However, misoprostol is less expensive and more effective than the dinoprostone vaginal insert.

A comparison of intermittent vaginal administration of misoprostol with continuous dinoprostone for cervical ripening and labor induction

Objective: Our purpose was to compare the effect of vaginal administration of misoprostol (Cytotec) with that of dinoprostone (Cervidil) on cervical ripening and labor induction. Study design: Two hundred patients with indications for induction of labor and unfavorable cervical examinations were randomly assigned to receive vaginally administered misoprostol (prostaglandin E 1) or the dinoprostone (prostaglandin E 2) vaginal insert. Twenty-five microgram tablets of misoprostol were placed in the posterior vaginal fornix every 4 hours for a maximum of six doses. Additional misoprostol was not given after either spontaneous rupture of membranes, adequate cervical ripening (Bishop score of ≥8 or cervical dilatation of ≥3 cm), or beginning of active labor. The vaginal insert, Cervidil, containing 10 mg of dinoprostone in a timed-release preparation was placed in the posterior vaginal fornix for a maximum period of 24 hours. The vaginal insert was removed for spontaneous rupture of membranes, entry into active labor, adequate cervical ripening, or abnormality of uterine contractile pattern or fetal cardiac activity. Results: Of the 200 patients enrolled, 99 were randomized to misoprostol and 101 to dinoprostone. The average interval from start of induction to vaginal delivery was 1 hour shorter in the misoprostol group (1296.7 ± 722.1 minutes) than in the dinoprostone group (1360.0 ± 792.0 minutes), but this difference was not statistically significant ( p = 0.97). Oxytocin augmentation of labor was used in 50 (50.5%) misoprostol-treated patients and 43 (43.5%) dinoprostone-treated patients (relative risk 1.14, 95% confidence interval 0.86 to 1.51, p = 0.35). There were no significant differences between routes of delivery with misoprostol or dinoprostone. Overall, 38 patients (19.3%) had cesarean deliveries. There was a significantly lower prevalence of tachysystole (six or more uterine contractions in a 10-minute window for two consecutive 10-minute periods) in the misoprostol group (7.1%) than in the dinoprostone group (18.4%) (relative risk 0.52, 95% confidence interval 0.31 to 0.89, p = 0.02). There were no significant differences in frequency of uterine hyperstimulation or hypertonus. Abnormal fetal heart rate tracings were found in 23 (23.2%) of misoprostol-treated patients and 35 (35.7%) of dinoprostone-treated patients (relative risk 0.73, 95% confidence interval 0.52 to 1.01, p = 0.0546). No significant differences were found in meconium passage, 1- or 5-minute Apgar scores <7, neonatal resuscitations, or admissions to the neonatal intensive care unit between the two groups. CONCLUSIONS: Vaginally administered misoprostol is as effective as dinoprostone for cervical ripening and the induction of labor. Mean time intervals to delivery, need for oxytocin augmentation, and routes of delivery were similar between the two groups. Incidence of uterine tachysystole with misoprostol every 4 hours was significantly less than with dinoprostone.

Labor induction with intravaginal misoprostol in term premature rupture of membranes: A randomized study

To evaluate the safety and clinical effectiveness of intravaginal misoprostol, a synthetic prostaglandin E1 analogue, for labor induction in gravidas with premature rupture of membranes (PROM) at term. One hundred forty-one pregnant women with term PROM were assigned randomly to one of two induction groups: 1) intravaginal misoprostol or 2) intravenous oxytocin by continuous infusion. Seventy subjects were allocated to the misoprostol group and 71 to the oxytocin group. The mean (+/- standard deviation) interval from induction to delivery was significantly shorter in the misoprostol group (416 +/- 276 compared with 539 +/- 372 minutes; P = .04). In 85.7% of patients in the misoprostol group, only one dose was required. Intrapartum complication rates, mode of delivery, and neonatal or maternal adverse event rates were similar in the two treatment groups. Uterine tachysystole occurred more frequently with misoprostol than with oxytocin (28.6% compared with 14.0%; P < .04). Intravaginal administration of misoprostol induces labor safely and effectively in patients with PROM at term.

A Randomized Trial of Misoprostol and Oxytocin for Induction of Labor

In Brief Objective To compare the safety and efficacy of misoprostol and oxytocin for induction of labor. Methods One hundred thirty women requiring induction of labor were randomized to receive either intravenous oxytocin or 100 μg misoprostol, administered intravaginally every 4 hours until labor was established. Results Compared with women receiving oxytocin, a greater percentage of women in the misoprostol group had Bishop scores of 3 or less (58 versus 38%, P < .05). Nonetheless, the median induction-to-delivery interval was significantly shorter (585 versus 885 minutes, P < .001) in the misoprostol group. Women in the misoprostol group were more likely to deliver vaginally within 24 hours of the start of induction (77 versus 55%, P < .002). Epidural analgesia was used more frequently in women receiving oxytocin than in those receiving misoprostol (73 versus 50%, P = .025). The total percentage of cesarean deliveries was not significantly different, although the percentage of cesarean deliveries for dystocia was lower in the misoprostol group (8 versus 21%, P = .02). Uterine tachysystole was significantly more common (70 versus 11%, P < .001) and hospital charges significantly less with misoprostol. Conclusion Compared with oxytocin for labor induction, misoprostol results in a shorter induction-to-delivery interval, a reduction in the rate of cesarean delivery for dystocia, and a decreased use of epidural analgesia. Uterine tachysystole is significantly more common with the use of misoprostol. Compared with oxytocin, misoprostol results in a shorter induction-delivery interval, a decreased rate of cesarean for dystocia, and lower hospital charges.

A randomized trial of misoprostol and oxytocin for induction of labor: Safety and efficacy

To compare the safety and efficacy of misoprostol and oxytocin for induction of labor. One hundred thirty women requiring induction of labor were randomized to receive either intravenous oxytocin or 100 micrograms misoprostol, administered intravaginally every 4 hours until labor was established. Compared with women receiving oxytocin, a greater percentage of women in the misoprostol group had Bishop scores of 3 or less (58 versus 38%, P < .05). Nonetheless, the median induction-to-delivery interval was significantly shorter (585 versus 885 minutes, P < .001) in the misoprostol group. Women in the misoprostol group were more likely to deliver vaginally within 24 hours of the start of induction (77 versus 55%, P < .002). Epidural analgesia was used more frequently in women receiving oxytocin than in those receiving misoprostol (73 versus 50%, P = .025). The total percentage of cesarean deliveries was not significantly different, although the percentage of cesarean deliveries for dystocia was lower in the misoprostol group (8 versus 21%, P = .02). Uterine tachysystole was significantly more common (70 versus 11%, P < .001) and hospital charges significantly less with misoprostol. Compared with oxytocin for labor induction, misoprostol results in a shorter induction-to-delivery interval, a reduction in the rate of cesarean delivery for dystocia, and a decreased use of epidural analgesia. Uterine tachysystole is significantly more common with the use of misoprostol.

Circulating excitations and re-entry in the pregnant uterus.

The propagation of individual action potentials during spontaneous bursts of activity in isolated pregnant rat myometrium in the final stage of pregnancy was analyzed. Simultaneous recordings from 240 extracellular recording sites (inter-electrode distance 1 mm) made it possible to reconstruct, in spatial and temporal details, the conduction of the electrical impulse. On several occasions, the impulse was seen to be conducted in a circular fashion whereby the impulse repeatedly re-excited the myometrium. No evidence was found of circuits rotating around an area of depressed excitability or anatomical obstacle, suggesting that these circuits are similar to those proposed to occur in cardiac muscle by the "leading circuit" model. Because of the anisotropic conduction properties of the myometrium, several circuits revolved in an ellipse with the long axis parallel to the longitudinal fiber direction, similar to functional re-entry in the anisotropic ventricle. Of a total of 46 bursts analyzed, myometrial re-entry occurred in 10 of the bursts. Furthermore, re-entries were found at day 17, day 19 and day 21 ( = term) stages of pregnancy suggesting that re-entry may occur throughout the final stage of gestation. In conclusion, functional re-entry, previously shown in the myocardium, may also occur in the pregnant myometrium. The presence of re-entry in the uterus could underlie the mechanism for uterine tachysystole, leading to dysfunctional labor.

Preinduction Cervical Ripening with Intravaginal Prostaglandin E1 Methyl Analogue Misoprostol: A Randomized Controlled Trial

To evaluate the efficacy of intravaginal prostaglandin E1 methyl analogue misoprostol in cervical ripening in patients with unfavorable cervix (Bishop score < 4) requiring labor induction. A randomized controlled clinical trial of 62 women in the third trimester with various indications for induction of labor were randomly allocated to receive either 100 micrograms misoprostol inserted vaginally (32) or placebo similarly applied (30). Transvaginal sonography was performed to measure the cervical length before and 12 hrs after insertion. The mean change in cervical length and Bishop score was significantly greater in the misoprostol group (24 mm and score 8) compared with in the placebo group (2.2 mm and score 1) (p = 0.001). All but one patients receiving misoprostol went into labor while only one in the placebo group did so. The interval from insertion to vaginal delivery was significantly shorter in the misoprostol group (12.0 vs 25.5 hrs, p < 0.001). Delivery occurred within 24 hrs in 75% and 30% of patients in the misoprostol and placebo groups respectively. Uterine tachsystole occurred more frequently in the misoprostol group (38%) than in the placebo group (0%) (p < 0.001). All could be rapidly reversed by tocolytics without apparent untoward intrapartum effects. No significant differences were noted in the 2 groups in terms of perinatal outcomes and mode of delivery. Intravaginal misoprostol is an effective, cheap and safe method for cervical ripening. The higher frequency of uterine tachysystole in the misoprostol group did not increase the risk of adverse intrapartum and neonatal outcomes.