Labor, induced Archives - Revista Brasileira de Ginecologia e Obstetrícia
Summary
Revista Brasileira de Ginecologia e Obstetrícia. 2013;35(2):60-65
DOI 10.1590/S0100-72032013000200004
PURPOSE: To evaluate the effectiveness and the safety of orally administered misoprostol in comparison to intravenously infused oxytocin for labor induction in term pregnant women. METHODS: Between 2008 and 2010, a total of 285 term pregnant women whom were candidate for vaginal delivery were assessed for eligibility to enter the study. Twenty five patients were excluded for different reasons; and 260 included women were randomly assigned to one of the two groups according to the method of treatment, misoprostol or oxytocin. The misoprostol group received 25 µg every 2 hours for up to 24 hours for induction. The oxytocin group received an infusion of 10 IU which was gradually increased. The time from induction to delivery and induction to the beginning of the active phase and successful inductions within 12, 18, and 24 hours were recorded. The trial is registered at irct.ir, number IRCT2012061910068N1. RESULTS: Failure of induction, leading to caesarean section was around 38.3% in the oxytocin group and significantly higher than that of the misoprostol group (20.3%) (p<0.001). Despite the more prevalent failure in the oxytocin group, the mean time intervals from induction to active phase and labor of this group were both significantly less than the misoprostol group (10.1±6.1 and 13.2±7.7 versus 12.9±5.4 and 15.6±5.1 hours respectively, both p-values were <0.05). Maternal and fetal complications were comparable between groups except gastrointestinal symptoms which were encountered more frequently in the misoprostol (10.9 versus 3.9%, p=0.03). CONCLUSIONS: Misoprostol is a safe and effective drug with low complications for the induction of labor. Failure is seen less with misoprostol and caesarean sections are less frequently indicated as compared to oxytocin.
Summary
Revista Brasileira de Ginecologia e Obstetrícia. 2013;35(2):60-65
DOI 10.1590/S0100-72032013000200004
PURPOSE: To evaluate the effectiveness and the safety of orally administered misoprostol in comparison to intravenously infused oxytocin for labor induction in term pregnant women. METHODS: Between 2008 and 2010, a total of 285 term pregnant women whom were candidate for vaginal delivery were assessed for eligibility to enter the study. Twenty five patients were excluded for different reasons; and 260 included women were randomly assigned to one of the two groups according to the method of treatment, misoprostol or oxytocin. The misoprostol group received 25 µg every 2 hours for up to 24 hours for induction. The oxytocin group received an infusion of 10 IU which was gradually increased. The time from induction to delivery and induction to the beginning of the active phase and successful inductions within 12, 18, and 24 hours were recorded. The trial is registered at irct.ir, number IRCT2012061910068N1. RESULTS: Failure of induction, leading to caesarean section was around 38.3% in the oxytocin group and significantly higher than that of the misoprostol group (20.3%) (p<0.001). Despite the more prevalent failure in the oxytocin group, the mean time intervals from induction to active phase and labor of this group were both significantly less than the misoprostol group (10.1±6.1 and 13.2±7.7 versus 12.9±5.4 and 15.6±5.1 hours respectively, both p-values were <0.05). Maternal and fetal complications were comparable between groups except gastrointestinal symptoms which were encountered more frequently in the misoprostol (10.9 versus 3.9%, p=0.03). CONCLUSIONS: Misoprostol is a safe and effective drug with low complications for the induction of labor. Failure is seen less with misoprostol and caesarean sections are less frequently indicated as compared to oxytocin.
Summary
Revista Brasileira de Ginecologia e Obstetrícia. 2012;34(4):164-169
DOI 10.1590/S0100-72032012000400005
PURPOSE: To describe the maternal and perinatal outcomes after the use of 12.5 µg of sublingual misoprostol for labor induction in women with term pregnancy and a live fetus. METHODS: We conducted a multicenter, open and non-randomized clinical trial during the period from July to December 2009. We included 30 pregnant women with an indication for labor induction at term, carrying a live fetus, with a Bishop score of six or less, cephalic presentation, estimated fetal weight of less than 4,000 g and an amniotic fluid index greater than five. We excluded women with a previous uterine scar, non-reassuring fetal status, congenital anomalies, multiple pregnancy, intrauterine growth restriction, genital bleeding, and contraindications of vaginal delivery. A tablet of 12.5 µg sublingual misoprostol was administered every six hours, until the beginning of labor, with the maximum of eight doses. RESULTS: Labor was successfully induced in 90% of pregnant women. The mean interval between the first dose and the onset of uterine contractions and delivery was 14.3±11.7 hours and 25.4±13 hours, respectively. The frequency of vaginal delivery was 60%. Uterine tachysystole occurred in two pregnant women, being reversed in both cases without the need for cesarean section. Meconium-stained amniotic fluid was observed in four patients, and an Apgar score of less than 7 at five minutes in only one newborn. CONCLUSION: Maternal and perinatal outcomes were favorable after induction of labor with sublingual misoprostol at a dose of 12.5 µg every six hours. However, controlled trials are needed to compare this regimen with other doses and routes of administration.
Summary
Revista Brasileira de Ginecologia e Obstetrícia. 2012;34(4):164-169
DOI 10.1590/S0100-72032012000400005
PURPOSE: To describe the maternal and perinatal outcomes after the use of 12.5 µg of sublingual misoprostol for labor induction in women with term pregnancy and a live fetus. METHODS: We conducted a multicenter, open and non-randomized clinical trial during the period from July to December 2009. We included 30 pregnant women with an indication for labor induction at term, carrying a live fetus, with a Bishop score of six or less, cephalic presentation, estimated fetal weight of less than 4,000 g and an amniotic fluid index greater than five. We excluded women with a previous uterine scar, non-reassuring fetal status, congenital anomalies, multiple pregnancy, intrauterine growth restriction, genital bleeding, and contraindications of vaginal delivery. A tablet of 12.5 µg sublingual misoprostol was administered every six hours, until the beginning of labor, with the maximum of eight doses. RESULTS: Labor was successfully induced in 90% of pregnant women. The mean interval between the first dose and the onset of uterine contractions and delivery was 14.3±11.7 hours and 25.4±13 hours, respectively. The frequency of vaginal delivery was 60%. Uterine tachysystole occurred in two pregnant women, being reversed in both cases without the need for cesarean section. Meconium-stained amniotic fluid was observed in four patients, and an Apgar score of less than 7 at five minutes in only one newborn. CONCLUSION: Maternal and perinatal outcomes were favorable after induction of labor with sublingual misoprostol at a dose of 12.5 µg every six hours. However, controlled trials are needed to compare this regimen with other doses and routes of administration.
Summary
Revista Brasileira de Ginecologia e Obstetrícia. 2011;33(11):361-366
DOI 10.1590/S0100-72032011001100007
PURPOSE: to compare the accuracy of transvaginal ultrasonographic measurement of the uterine cervix with Bishop’s score for the prediction of vaginal delivery after labor induction, with 25 mcg of misoprostol. METHODS: a prospective study for the validation of a diagnostic test was conducted on 126 pregnant women with indication for labor induction. The patients were evaluated by Bishop’s score and transvaginal ultrasonography for cervical measurement. They also undergone obstetric transabdominal ultrasound to evaluate static and fetal weight, as well as the amniotic fluid index, and basal cardiotocography for the evaluation of fetal vitality. Labor was induced with vaginal and sublingual misoprostol, one of the tablets containing 25 mcg of the drug and the other only placebo. The tablets were administered every six hours, with a maximum number of eight. Frequency tables were obtained, and measures of central tendency and dispersion were calculated. ROC curves were constructed for the evaluation of Bishop’s score and ultrasonographic measurement of the uterine cervix for the prediction of vaginal delivery. RESULTS: the area under the ROC curve was 0.5 (p=0.8) for the ultrasonographic measurement of the uterine cervix, and 0.6 (p=0.02) for Bishop’s score (cut point ³4). Bishop’s score had a sensitivity of 56.2% and specificity of 67.9% for prediction of vaginal delivery, with a positive likelihood ratio of 1.75 and a negative one of 0.65. CONCLUSIONS: ultrasonographic measurement of the uterine cervix was not a good predictor of evolution to vaginal delivery among patients with misoprostol-induced labor. Bishop’s score was a better predictor of vaginal delivery under these circumstances.
Summary
Revista Brasileira de Ginecologia e Obstetrícia. 2011;33(11):361-366
DOI 10.1590/S0100-72032011001100007
PURPOSE: to compare the accuracy of transvaginal ultrasonographic measurement of the uterine cervix with Bishop’s score for the prediction of vaginal delivery after labor induction, with 25 mcg of misoprostol. METHODS: a prospective study for the validation of a diagnostic test was conducted on 126 pregnant women with indication for labor induction. The patients were evaluated by Bishop’s score and transvaginal ultrasonography for cervical measurement. They also undergone obstetric transabdominal ultrasound to evaluate static and fetal weight, as well as the amniotic fluid index, and basal cardiotocography for the evaluation of fetal vitality. Labor was induced with vaginal and sublingual misoprostol, one of the tablets containing 25 mcg of the drug and the other only placebo. The tablets were administered every six hours, with a maximum number of eight. Frequency tables were obtained, and measures of central tendency and dispersion were calculated. ROC curves were constructed for the evaluation of Bishop’s score and ultrasonographic measurement of the uterine cervix for the prediction of vaginal delivery. RESULTS: the area under the ROC curve was 0.5 (p=0.8) for the ultrasonographic measurement of the uterine cervix, and 0.6 (p=0.02) for Bishop’s score (cut point ³4). Bishop’s score had a sensitivity of 56.2% and specificity of 67.9% for prediction of vaginal delivery, with a positive likelihood ratio of 1.75 and a negative one of 0.65. CONCLUSIONS: ultrasonographic measurement of the uterine cervix was not a good predictor of evolution to vaginal delivery among patients with misoprostol-induced labor. Bishop’s score was a better predictor of vaginal delivery under these circumstances.
Summary
Revista Brasileira de Ginecologia e Obstetrícia. 2011;33(3):118-122
DOI 10.1590/S0100-72032011000300003
PURPOSE: to determine the efficacy and safety of dinoprostone and misoprostol for the induction of vaginal childbirth, with or without the use of oxytocin in nulliparous women. METHODS: in this retrospective observational study, 238 patients were subjected to the induction of delivery from January 2008 to February 2010 with the use of misoprostol 25 mcg by the vaginal route or a pessary containing 10 mg of dinoprostone. A total of 184 patients were selected, with the following characteristics: nulliparous, gestational age of 37-42 weeks, singleton pregnancies, cephalic presentation, intact membranes, and Bishop score < 3. Obstetric and neonatal data were analyzed and compared between groups. The Student t-test, chi-square test and Fisher's exact test were used for statistical analysis, with the level of significance set at p<0.05. RESULTS: the rate of vaginal childbirth did not differ significantly in patients who used misoprostol and dinoprostone (43.2% versus 50%; p = 0.35, respectively). The ripening of cervix was higher in the group treated with misoprostol (87.3% versus 75.6%, p=0.04). The use of oxytocin was necessary in 58.8% of the misoprostol group and 57.3% in the dinoprostone group after the ripening of cervix. Failed induction was the primary indication of caesarean section delivery in both groups, with no significant difference between them. Fetal and maternal adverse events, such as tachysystole and Apgar scores were similar. CONCLUSION: dinoprostone and misoprostol are both effective for vaginal childbirth induction, although they need to be combined with oxytocin. They showed a similar safety profile, with misoprostol being more efficient regarding cervical ripening.
Summary
Revista Brasileira de Ginecologia e Obstetrícia. 2011;33(3):118-122
DOI 10.1590/S0100-72032011000300003
PURPOSE: to determine the efficacy and safety of dinoprostone and misoprostol for the induction of vaginal childbirth, with or without the use of oxytocin in nulliparous women. METHODS: in this retrospective observational study, 238 patients were subjected to the induction of delivery from January 2008 to February 2010 with the use of misoprostol 25 mcg by the vaginal route or a pessary containing 10 mg of dinoprostone. A total of 184 patients were selected, with the following characteristics: nulliparous, gestational age of 37-42 weeks, singleton pregnancies, cephalic presentation, intact membranes, and Bishop score < 3. Obstetric and neonatal data were analyzed and compared between groups. The Student t-test, chi-square test and Fisher's exact test were used for statistical analysis, with the level of significance set at p<0.05. RESULTS: the rate of vaginal childbirth did not differ significantly in patients who used misoprostol and dinoprostone (43.2% versus 50%; p = 0.35, respectively). The ripening of cervix was higher in the group treated with misoprostol (87.3% versus 75.6%, p=0.04). The use of oxytocin was necessary in 58.8% of the misoprostol group and 57.3% in the dinoprostone group after the ripening of cervix. Failed induction was the primary indication of caesarean section delivery in both groups, with no significant difference between them. Fetal and maternal adverse events, such as tachysystole and Apgar scores were similar. CONCLUSION: dinoprostone and misoprostol are both effective for vaginal childbirth induction, although they need to be combined with oxytocin. They showed a similar safety profile, with misoprostol being more efficient regarding cervical ripening.
Summary
Revista Brasileira de Ginecologia e Obstetrícia. 2010;32(7):346-351
DOI 10.1590/S0100-72032010000700007
PURPOSE: to compare the effectiveness of the Foley balloon with vaginal misoprostol for cervical ripening and labor induction. METHODS: randomized clinical trial, not blind, conducted from January 2006 to January 2008. A total of 160 pregnant women with indication for induction of labor were included and divided into two groups, 80 for Foley and 80 for vaginal misoprostol. Inclusion criteria were: gestational age of 37 weeks or more, a live single fetus with cephalic presentation and a Bishop score of four or less. We excluded patients with a uterine scar, ruptured membranes, estimated fetal weight greater than 4000 g, placenta previa, chorioamnionitis and conditions that imposed the immediate termination of pregnancy. Statistical tests employed were Mann-Whitney, χ2 test or Fisher's exact test, and p value was significant if less than 0.005. RESULTS: misoprostol triggered more frequently spontaneous delivery (50.0 versus 15.0% for Foley, p<0.001) and required less use of oxytocin (41.2 versus 76.2%), and this group presented more tachysystole (21.2 versus 5.0%). The Foley catheter caused more discomfort to the patient (28.7 versus 1.2%). There were no differences in the time required for development of the Bishop score (20.69 versus 21.36 hours), for triggering delivery (36.42 versus 29.57 hours) or in rates of cesarean delivery (51.2 versus 42.5%). There were no significant differences in perinatal performance, with similar rates of abnormal cardiotocography (20.0 versus 21.2%), presence of meconium (13.7 versus 17.5%) and need for neonatal intensive care unit (3.7 versus 6.2%). CONCLUSIONS: the use of the Foley catheter was as effective as misoprostol for cervical ripening, but less effective in triggering spontaneous labor. Our results support the recommendation of its use for cervical ripening, especially in patients with cesarean scar.
Summary
Revista Brasileira de Ginecologia e Obstetrícia. 2010;32(7):346-351
DOI 10.1590/S0100-72032010000700007
PURPOSE: to compare the effectiveness of the Foley balloon with vaginal misoprostol for cervical ripening and labor induction. METHODS: randomized clinical trial, not blind, conducted from January 2006 to January 2008. A total of 160 pregnant women with indication for induction of labor were included and divided into two groups, 80 for Foley and 80 for vaginal misoprostol. Inclusion criteria were: gestational age of 37 weeks or more, a live single fetus with cephalic presentation and a Bishop score of four or less. We excluded patients with a uterine scar, ruptured membranes, estimated fetal weight greater than 4000 g, placenta previa, chorioamnionitis and conditions that imposed the immediate termination of pregnancy. Statistical tests employed were Mann-Whitney, χ2 test or Fisher's exact test, and p value was significant if less than 0.005. RESULTS: misoprostol triggered more frequently spontaneous delivery (50.0 versus 15.0% for Foley, p<0.001) and required less use of oxytocin (41.2 versus 76.2%), and this group presented more tachysystole (21.2 versus 5.0%). The Foley catheter caused more discomfort to the patient (28.7 versus 1.2%). There were no differences in the time required for development of the Bishop score (20.69 versus 21.36 hours), for triggering delivery (36.42 versus 29.57 hours) or in rates of cesarean delivery (51.2 versus 42.5%). There were no significant differences in perinatal performance, with similar rates of abnormal cardiotocography (20.0 versus 21.2%), presence of meconium (13.7 versus 17.5%) and need for neonatal intensive care unit (3.7 versus 6.2%). CONCLUSIONS: the use of the Foley catheter was as effective as misoprostol for cervical ripening, but less effective in triggering spontaneous labor. Our results support the recommendation of its use for cervical ripening, especially in patients with cesarean scar.
Summary
Revista Brasileira de Ginecologia e Obstetrícia. 2010;32(5):208-213
DOI 10.1590/S0100-72032010000500002
PURPOSE: to test effectiveness and safety of the oral administration of a new misoprostol formulation in titrated doses for the induction of delivery of a live fetus at term. METHODS: an open pilot multicenter, non-randomized clinical trial was conducted from July to December 2008. A total of 30 patients with indications for induction of labor were included. The patients had a live fetus, Bishop score <6, vertex presentation, fetal weight <4,000g estimated by ultrasonography and amniotic fluid index >5. Exclusion criteria were previous uterine scar, non-reassuring fetal heart rate tracing, multiple pregnancy, fetal growth restriction, genital hemorrhage and presence of genital tumors, ulcerations or malformations. An initial dose of 20µg/hour of the oral misoprostol solution was used in the first 6 hours, and was increased progressively to 20µg/hour every 6 hours if labor did not start, up to a maximum dose of 80µg/h in the first 24 hours, maintained for additional 24 hours if necessary. RESULTS: labor was satisfactorily induced in 96.7% of patients. The interval between the first dose and the beginning of uterine contractions was 3.8±1.8 hours. The interval between the initial dose and delivery varied from 6 to 24 hours. The frequency of vaginal delivery was 80% (24 cases). Most of the patients (60%; n=18) initiated labor with a dose of 20mg/hour. Tachysystole occurred in 13.3% of women and meconium-stained fluid was detected in 20% of cases. There were two cases of Apgar scores <7 in the first minute and no Apgar score <7 in the fifth minute. CONCLUSIONS: the oral solution of misoprostol was effective and safe for the induction of labor. However, further randomized controlled trials are needed to compare this new formulation with misoprostol administered by the vaginal route.
Summary
Revista Brasileira de Ginecologia e Obstetrícia. 2010;32(5):208-213
DOI 10.1590/S0100-72032010000500002
PURPOSE: to test effectiveness and safety of the oral administration of a new misoprostol formulation in titrated doses for the induction of delivery of a live fetus at term. METHODS: an open pilot multicenter, non-randomized clinical trial was conducted from July to December 2008. A total of 30 patients with indications for induction of labor were included. The patients had a live fetus, Bishop score <6, vertex presentation, fetal weight <4,000g estimated by ultrasonography and amniotic fluid index >5. Exclusion criteria were previous uterine scar, non-reassuring fetal heart rate tracing, multiple pregnancy, fetal growth restriction, genital hemorrhage and presence of genital tumors, ulcerations or malformations. An initial dose of 20µg/hour of the oral misoprostol solution was used in the first 6 hours, and was increased progressively to 20µg/hour every 6 hours if labor did not start, up to a maximum dose of 80µg/h in the first 24 hours, maintained for additional 24 hours if necessary. RESULTS: labor was satisfactorily induced in 96.7% of patients. The interval between the first dose and the beginning of uterine contractions was 3.8±1.8 hours. The interval between the initial dose and delivery varied from 6 to 24 hours. The frequency of vaginal delivery was 80% (24 cases). Most of the patients (60%; n=18) initiated labor with a dose of 20mg/hour. Tachysystole occurred in 13.3% of women and meconium-stained fluid was detected in 20% of cases. There were two cases of Apgar scores <7 in the first minute and no Apgar score <7 in the fifth minute. CONCLUSIONS: the oral solution of misoprostol was effective and safe for the induction of labor. However, further randomized controlled trials are needed to compare this new formulation with misoprostol administered by the vaginal route.
Summary
Revista Brasileira de Ginecologia e Obstetrícia. 2008;30(12):620-625
DOI 10.1590/S0100-72032008001200006
PURPOSE: to compare delivery and pregnancy follow-up among adolescent and non-adolescent pregnant women whose delivery occurred in a tertiary hospital from Região de Lisboa (Portugal). METHODS: retrospective study with 10,656 deliveries. Pregnancy follow-up, delivery type, need of episiotomy and severe lacerations, Apgar index at the fifth minute and the delivery weight have been evaluated. The pregnant women were divided into two groups, over and under 20 years old. The group with women under 20 was further subdivided in pregnant women under or over 16. The χ2 test has been used for statistical analysis. RESULTS: adolescents presented worse follow-up: first appointment after 12 weeks (46.4 versus 26.3%) and less than four appointments (8.1 versus 3.1%), less dystocia (21.5 versus 35.1%), less caesarian sections (10.6 versus 20.7%), and lower need for inducing labor (16.5 versus 26.5%). There was no significant difference concerning gestational age at delivery and ratio of low weight newborns. Among adolescents, the ones under 16 had more low weight newborns (12 versus 7.4%) and more deliveries between 34 and 37 weeks (10.8 versus 4.2%). CONCLUSIONS: in a hospital attending adolescents with social and psychological support, the fact of them having had a worse follow-up in the pre-natal phase, their performance has not been worse. Nevertheless, special attention might be given to pregnant women under 16.
Summary
Revista Brasileira de Ginecologia e Obstetrícia. 2008;30(12):620-625
DOI 10.1590/S0100-72032008001200006
PURPOSE: to compare delivery and pregnancy follow-up among adolescent and non-adolescent pregnant women whose delivery occurred in a tertiary hospital from Região de Lisboa (Portugal). METHODS: retrospective study with 10,656 deliveries. Pregnancy follow-up, delivery type, need of episiotomy and severe lacerations, Apgar index at the fifth minute and the delivery weight have been evaluated. The pregnant women were divided into two groups, over and under 20 years old. The group with women under 20 was further subdivided in pregnant women under or over 16. The χ2 test has been used for statistical analysis. RESULTS: adolescents presented worse follow-up: first appointment after 12 weeks (46.4 versus 26.3%) and less than four appointments (8.1 versus 3.1%), less dystocia (21.5 versus 35.1%), less caesarian sections (10.6 versus 20.7%), and lower need for inducing labor (16.5 versus 26.5%). There was no significant difference concerning gestational age at delivery and ratio of low weight newborns. Among adolescents, the ones under 16 had more low weight newborns (12 versus 7.4%) and more deliveries between 34 and 37 weeks (10.8 versus 4.2%). CONCLUSIONS: in a hospital attending adolescents with social and psychological support, the fact of them having had a worse follow-up in the pre-natal phase, their performance has not been worse. Nevertheless, special attention might be given to pregnant women under 16.
Summary
Revista Brasileira de Ginecologia e Obstetrícia. 2007;29(12):639-646
DOI 10.1590/S0100-72032007001200007
PURPOSE: to compare the effectiveness of low doses of vaginal misoprostol (12.5 versus 25 µg) for induction of labor. METHODS: a double-blind, randomized, controlled clinical trial was performed in Santa Casa de Misericórdia de Sobral, from May 2005 to April 2006. Sixty-two term pregnant women, with intact membranes and with indication for labor induction, were included. They randomly received 25 µg (32) or 12.5 µg (30) of vaginal misoprostol each four hours, until the maximum of eight doses. Mode of delivery, time between induction and delivery, perinatal complications, and maternal side effects were studied. The control variables were maternal and gestational ages, parity and Bishop score. The statistical tests used were average calculations, shunting line-standards and Student t-test (numerical continuous variables), chi2 (categorical variables) and Mann-Whitney test (discrete variables). RESULTS: the two groups, 12.5 and 25 µg, did not differ in relation to the interval of time between the induction onset and delivery (1524 versus 1212 min, p=0.333), in the frequency of vaginal delivery (70 versus 71.8%, p=0.720), Apgar scores below seven at the fifth minute (3,3 versus 6,25%, p=0.533) and tachysystole frequency (3.3 versus 9.3%, p=0.533). The average of total dose administered was significantly higher in the 25 µg group (40 versus 61.2 µg, p=0.03). CONCLUSIONS: vaginal misoprostol in the dose of 12.5 µg was efficient, with collateral effects similar, to the 25 µg of vaginal misoprostol, for induction of labor at term.
Summary
Revista Brasileira de Ginecologia e Obstetrícia. 2007;29(12):639-646
DOI 10.1590/S0100-72032007001200007
PURPOSE: to compare the effectiveness of low doses of vaginal misoprostol (12.5 versus 25 µg) for induction of labor. METHODS: a double-blind, randomized, controlled clinical trial was performed in Santa Casa de Misericórdia de Sobral, from May 2005 to April 2006. Sixty-two term pregnant women, with intact membranes and with indication for labor induction, were included. They randomly received 25 µg (32) or 12.5 µg (30) of vaginal misoprostol each four hours, until the maximum of eight doses. Mode of delivery, time between induction and delivery, perinatal complications, and maternal side effects were studied. The control variables were maternal and gestational ages, parity and Bishop score. The statistical tests used were average calculations, shunting line-standards and Student t-test (numerical continuous variables), chi2 (categorical variables) and Mann-Whitney test (discrete variables). RESULTS: the two groups, 12.5 and 25 µg, did not differ in relation to the interval of time between the induction onset and delivery (1524 versus 1212 min, p=0.333), in the frequency of vaginal delivery (70 versus 71.8%, p=0.720), Apgar scores below seven at the fifth minute (3,3 versus 6,25%, p=0.533) and tachysystole frequency (3.3 versus 9.3%, p=0.533). The average of total dose administered was significantly higher in the 25 µg group (40 versus 61.2 µg, p=0.03). CONCLUSIONS: vaginal misoprostol in the dose of 12.5 µg was efficient, with collateral effects similar, to the 25 µg of vaginal misoprostol, for induction of labor at term.