Comparison of intravenous oxytocin and vaginal prostaglandin E2 gel in women with unripe cervixes and premature rupture of the membranes

To induce cervical priming and labor, 20 nulliparous term pregnant women with premature rupture of the membranes and unfavorable cervical states were randomly given either oxytocin intravenously or 4 mg prostaglandin E2 in gel intravaginally. One of ten women receiving oxytocin had a favorable cervical state within five hours and vaginal delivery within 24 hours after the start of the infusion compared with six of ten women after prostaglandin E2 gel application. This difference is statistically significant (P less than .01). The number of instrumental deliveries was nine (four cesarean sections and five vacuum extractions) in the oxytocin-treated patients compared with only two vacuum extractions in women who received prostaglandin E2 gel. This difference is also statistically significant (P less than .01, Fischer exact test). In a subsequent open study, 4 mg prostaglandin E2 gel was applied vaginally to 17 term pregnant women of mixed parity with premature rupture of the membranes and unfavorable cervixes. In 12 women a favorable cervical state was achieved within five hours after gel application, and all these women were delivered within 24 hours. None of the women required cesarean section but two required delivery by vacuum extraction. There were no perinatal losses, but two infants in the oxytocin-treated group had Apgar scores less than 7 at five minutes. At pediatric follow-up after two and six months, all infants were normal. In both obstetric and perinatal outcome prostaglandin E2 gel thus seems to be superior to oxytocin for labor induction in term pregnant patients with premature rupture of the membranes and unfavorable cervixes.     

Role of prostaglandin-induced cervical changes in labor induction

The role of the cervix in labor induction has been studied in a previous report. Cervical preparation by mechanical methods did not alter the course of induced labor. The same hypothesis is further elucidated in the present study using prostaglandin E2 vaginal suppositories for cervical preparation. Forty-seven pregnant women near term with Bishop scores of 4 or less were divided into three study groups: control subjects, oxytocin-treated patients, and prostaglandin group. A 12-hour preparation phase procedure was carried out to produce cervical and/or myometrial changes. All women had continuous measurement of uterine activity by an extraovular catheter. At the end of the preparation phase, the Bishop score was reevaluated, amniotomy carried out in all patients, and oxytocin infusion either started or continued. Although prostaglandin and oxytocin both significantly changed the cervix, oxytocin had the shortest induction-to-delivery interval, though the prostaglandin-treated group required lower concentrations of oxytocin. The authors conclude that with rigid control of Bishop score and timing of amniotomy and oxytocin infusion rates, prostaglandin-induced cervical changes alone did not uniquely benefit labor induction in the doses used, or within the time frame of the study.     

Use of prostaglandin E2 topical cervical gel in high-risk patients: a critical analysis

This investigation compared the safety and efficacy of 3- and 5-mg doses of prostaglandin E2 topical gel used for cervical ripening in 60 high-risk obstetric patients before oxytocin induction of labor. Both dosages significantly increased the Bishop score, unrelated to parity or gestational age. Induction time was significantly shortened, and the average maximum amount of oxytocin required was significantly less with the 5-mg dose, but not with the 3-mg dose, when compared with a placebo. Prostaglandin E2 did not influence the cesarean section rate. Uterine contractions were stimulated in 87.5% of the patients who received the drug, and 37.5% went into active labor, suggesting that prostaglandin E2 in these dosages is not an appropriate agent for local cervical ripening.     

Induction of labor by vaginal prostaglandin E2. A randomized study comparing pessaries with vaginal tablets.

A prospective randomized study of 267 pregnant women was undertaken to compare the efficacy of a pharmacy-prepared 3-mg prostaglandin E2 (PGE2) vaginal suppository with a 3-mg PGE2 vaginal tablet for induction of labor and cervical ripening. No statistically significant difference in success frequency was found between the two groups, either on the first day (72% and 74%, respectively; p greater than 0.05) or on the second day (89% in both groups). There was an equal proportion of women requiring oxytocin augmentation in the two groups, but the slower releasing properties of the vaginal tablet were reflected in a longer mean induction--delivery interval of about 4 h for this group. In both the pessary and the vaginal tablet groups, women who had not gone into labor on the first day showed a statistically significant increment in the Bishop score on the morning of the second day. The frequency of cesarean section was the same in both groups, but instrumental deliveries were more frequent in the vaginal tablet group. It is concluded that PGE2 vaginal tablets--a chemically stable alternative to pharmacy prepared pessaries--appear to be effective as regards cervical ripening as well as for labor induction.     

Induction of Labour in Nulliparas with Poor Cervical Score: Oxytocin or Prostaglandin Vaginal Pessaries?

In a previous study nulliparas with poor cervical score (less than 5 out of 10) had a 43.5% Caesarean section (CS) rate of which 55% were for failed induction when labour was induced by artificial rupture of membranes and oxytocin infusion. In this study induction of labour by 2 doses of 3 mg prostaglandin E2 (PGE2) vaginal pessaries, 4 hours apart, and if necessary by artificial rupture of membranes and oxytocin infusion 24 hours later, resulted in a CS rate of 23.7% of which 38.9% were for failed induction. The latter regimen resulted in a significantly lower CS rate compared with labour induced by oxytocin infusion and rupture of membranes without the use of prostaglandins (p less than 0.001). In the prostaglandin group 53.3% were established in labour within 24 hours of inserting the pessary and in these patients the CS rate was 18.5%. In those who did not start labour and needed rupture of membranes and oxytocin infusion 24 hours after the first pessary, 34 (47.9%) had a good cervical score (greater than or equal to 6 out of 10) and 37 (52.1%) had a poor cervical score (less than or equal to 5 out of 10) at the time of amniotomy. The CS rates in these groups were 8.8% and 48.6% respectively (p less than 0.001). In nulliparas with poor cervical score induction is better performed with vaginal prostaglandin pessaries in order to reduce the high CS rate associated with artificial rupture of membranes and oxytocin infusion.     

Induction of labour: a comparison of a single prostaglandin E2 vaginal tablet with amniotomy and intravenous oxytocin

Summary. In a randomized controlled study of 100 women of low parity and favourable induction features, induction of labour by means of a single vaginal tablet containing 3 mg of prostaglandin E₂ (PGE₂) was compared with the conventional method of amniotomy and intravenous oxytocin. Four of the patients (8%) who received the prostaglandin tablet required additional intravenous oxytocin to achieve delivery. The prostaglandin group had a longer mean overall induction-delivery interval but a shorter amniotomy-delivery interval than the oxytocin group. One patient in the PGE₂ group and two in the oxytocin group required caesarean section. The PGE₂ treated patients expressed a higher level of satisfaction with their method of induction, they required less analgesia, had less blood loss at delivery and their babies had a lower incidence of neonatal jaundice.     

Induction of labor with prostaglandin E2 vaginal suppositories

A prospective randomized study of 85 parturients was undertaken comparing the safety and efficacy of a 3-mg prostaglandin E2 vaginal suppository with intravenous oxytocin for the induction of labor. All patients were required to have a Bishop's score of 5 or higher. Labor was successfully induced in 98% of the patients in both groups by their respective methods. Sixty-four percent of the patients receiving a 3-mg prostaglandin E2 suppository required no intravenous oxytocin. More specifically, 82% (23/28) of the parous patients but only 29% (5/17) of the nulliparous patients who received a single 3-mg prostaglandin E2 suppository for labor induction did not require oxytocin augmentation (P less than .005). The first and second stages of labor were not significantly different for the two groups, and there was no significant difference in the incidence of cesarean section. A 3-mg prostaglandin E2 vaginal suppository may be a useful alternative to oxytocin for the induction of labor in carefully selected patients.     

Induction of labour for women with a previous Caesarean birth: a systematic review of the literature

AIMS: To compare the benefits and harms of planned elective repeat Caesarean section with induction of labour and to assess different methods of cervical ripening and induction of labour for women with a previous Caesarean birth who require induction of labour in a subsequent pregnancy. METHODS: The Cochrane controlled trials register and MEDLINE (1966-current) were searched using the following terms: vaginal birth after C(a)esare(i)an, trial of labo(u)r, elective C(a)esare(i)an, C(a)esare(i)an repeat, induction of labo(u)r, prostaglandins, prostaglandin E(2), misoprostol, prostaglandin E(1) analogs, mifepristone, oxytocin, Syntocinon, randomis(z)ed controlled trial, randomis(z)ed trial and clinical trial, to identify all published randomised controlled trials with reported data comparing outcomes for women and infants who have a planned elective repeat Caesarean section with induction of labour; and different methods of induction of labour, where a prior birth was by Caesarean section. RESULTS: There were no randomised controlled trials identified where women with a prior Caesarean birth, whose labour required induction in a subsequent pregnancy, compared elective repeat Caesarean section with induction of labour. There were three randomised controlled trials identified in which women with a prior Caesarean section were allocated to different methods of induction of labour - vaginal prostaglandin E(2) versus intravenous oxytocin; mifepristone versus placebo; and vaginal misoprostol versus intravenous oxytocin. These studies varied considerably in the methods used and meta-analysis was not appropriate. CONCLUSIONS: There is a paucity of safety information for induction of labour agents in the women with a scarred uterus, and caution should be exercised in their use.     

Comparison of Prostaglandin E2 Vaginal Tablet with Amniotomy and Intravenous Oxytocin for Induction of Labour

Summary: Prostaglandins have been increasingly used in obstetrical practice for cervical ripening and induction of labour. We set out to investigate the effectiveness of prostaglandin E₂ (PGE₂) vaginal pessaries in inducing labour in the Chinese population in Hong Kong. In the period August, 1991 to August, 1992, we recruited 206 pregnant Chinese women who required induction of labour for various obstetrical indications into the trial. The study group had induction of labour by PGE₂ vaginal pessaries and the control group underwent amniotomy plus oxytocin infusion. These patients were alternately assigned either method of induction. They were further divided into primiparous and multiparous (parity 1 and 2 only) groups.
Only 101 primiparas and 99 multiparas were available in the final analysis of the trial. Various aspects of labour, delivery, maternal and fetal outcome were compared. For primiparas, the traditional combined induction was the preferred method. For multiparas, both induction methods were quite satisfactory and there was a trend toward lesser blood loss and pethidine requirement in the PGE₂ users.     

A randomized trial of prostaglandin E2 in a controlled-release vaginal pessary for cervical ripening at term.

OBJECTIVE: The purpose of this study was to determine if prostaglandin E2 in a controlled-release vaginal pessary can produce cervical ripening at term. STUDY DESIGN: This was a double-blind, randomized, placebo-controlled study conducted at a university center and involving 81 patients with 42 receiving active agent. Categoric data were analyzed by Pearson's chi 2 or logistic regression. Continuous variables were analyzed by analysis of variance and the F test. RESULTS: Prostaglandin E2 was significantly better than placebo at cervical ripening and at decreasing the time to rupture of membranes, the time to onset of labor, the need to give oxytocin, and the time to vaginal delivery. Multiparous women benefitted more than primiparous ones. The cesarean section rate decreased only for multiparous women. Uterine hyperstimulation occurred only with prostaglandin E2 and after the onset of labor. CONCLUSIONS: Prostaglandin E2, when administered in a controlled-release vaginal pessary, is affective in producing cervical ripening at term. This agent should be used on inpatients who are under continuous monitoring and it should be removed at the onset of labor.     

A randomised comparison of early versus late amniotomy following cervical ripening with a Foley catheter

Objectives Ripening of the cervix with a Foley catheter commonly results in cervical dilatation without contractions. We examined the outcome of labour in women who underwent induction of labour using a Foley catheter, followed by either 1. early amniotomy, or 2. augmentation of labour by oxytocin and late amniotomy
Design Prospective randomised clinical trial
Setting Labour and delivery ward of a university teaching hospital
Participants Pregnant women ≥38 weeks of a singleton gestation, who had had no prior caesarean section
Methods All women underwent cervical ripening using a Foley catheter. Following removal of the catheter, women were randomly assigned to either early (   n = 80  ) or late amniotomy (   n = 88  ).
Main outcome measures Comparison of mode of delivery and duration of labour between the two groups
Results The rate of caesarean section was significantly higher in the early amniotomy group compared with the late amniotomy group (25% vs 7.9%; relative risk 1.74; 95% CI 1.3 – 2.34). The increase in caesarean section rate was due primarily to dystocia (15% vs 3.3%; relative risk 1.8; 95% CI 1.32 – 2.45). When excluding caesarean deliveries, no significant difference was found in duration of labour between the groups (8.3 hours (3.8) vs 7.7 hours (2.9))
Conclusions In women who undergo cervical ripening with a Foley catheter, augmentation of labour by oxytocin followed by amniotomy during active labour results in a lower rate of caesarean delivery for dystocia     

Predictors of vaginal delivery in patients with a previous cesarean section, who require oxytocin

Prospective analysis of 98 consecutive patients at term pregnancy with one previous cesarean section, who received oxytocin during a trial of labor (34 inductions, 64 augmentations), was undertaken to identify specific factors associated with successful vaginal delivery. The overall vaginal delivery rate was 59.2%. Comparing route of delivery in the induction and augmentation groups separately revealed no significant differences in maternal height, weight, or parity, duration of membrane rupture, length of oxytocin treatment or maximum dose, cervical examination on admission or before oxytocin treatment, or use of conduction anesthesia. A previous vaginal delivery favored repeat vaginal delivery in patients with augmentation while a nonrecurrent indication was significantly associated with vaginal delivery in all patients. After the beginning of oxytocin augmentation, the cervical dilatation rate was 1.82 cm/hr in patients delivered vaginally, compared with 0.18 cm/hr in those requiring cesarean section (p less than 0.001). Any cervical dilatation during the first 2 hours of augmentation was associated with more frequent vaginal delivery: 24 of 40 vaginal deliveries (60%) versus six of 24 cesarean sections (25%, p less than 0.01). Discriminant analysis correctly identified route of delivery in 85.3% of those with induction and 87.5% of patients with augmentation. During a trial of labor, oxytocin induction or augmentation is effective in a majority of patients. Furthermore, an early response during augmentation is of predictive value when such patients are being managed.     

Cervical ripening with transcervical foley catheter and the risk of uterine rupture

OBJECTIVE: To estimate whether the rate of uterine rupture in patients with a previous cesarean delivery is related to labor induction and/or cervical ripening using transcervical Foley catheter. METHODS: Charts of all patients who had a trial of labor after a previous cesarean delivery in our institution between 1988 and 2002 were reviewed. The rates of successful vaginal birth after cesarean delivery and uterine rupture in patients with spontaneous labor (control group) were compared with those of patients who underwent a labor induction by means of amniotomy with or without oxytocin and patients who underwent a labor induction/cervical ripening using a transcervical Foley catheter. Logistic regression analysis was performed to adjust for confounding variables. RESULTS: Of 2479 patients, 1807 had a spontaneous labor, 417 had labor induced by amniotomy with or without oxytocin, and 255 had labor induced by using transcervical Foley catheter. The rate of successful vaginal birth after cesarean delivery was significantly different among the groups (78.0% versus 77.9% versus 55.7%, P <.001), but not the rate of uterine rupture (1.1% versus 1.2% versus 1.6%, P =.81). After adjusting for confounding variables, the odds ratio (OR) for successful vaginal birth after cesarean delivery was 0.68 (95% confidence interval [CI] 0.41, 1.15), and the OR for uterine rupture was 0.47 (95% CI 0.06, 3.59) in patients who underwent an induction of labor using a transcervical Foley catheter when compared with patients with spontaneous labor. CONCLUSION: Labor induction using a transcervical Foley catheter was not associated with an increased risk of uterine rupture.     

Rate of uterine rupture during a trial of labor in women with one or two prior cesarean deliveries.

OBJECTIVE: We sought to determine whether there is a difference in the rate of symptomatic uterine rupture after a trial of labor in women who have had 1 versus 2 prior cesarean deliveries. STUDY DESIGN: The medical records of all women with a history of either 1 or 2 prior cesarean deliveries who elected to undergo a trial of labor during a 12-year period (July 1984-June 1996) at the Brigham and Women's Hospital were reviewed. Rates of uterine rupture were compared for these 2 groups. Potential confounding variables were controlled by using logistic regression analyses. RESULTS: Women with 1 prior cesarean delivery (n = 3757) had a rate of uterine rupture of 0.8%, whereas women with 2 prior cesarean deliveries (n = 134) had a rate of uterine rupture of 3.7% (P =.001). In a logistic regression analysis that was controlled for maternal age, use of epidural analgesia, oxytocin induction, oxytocin augmentation, the use of prostaglandin E(2) gel, birth weight, gestational age, type of prior hysterotomy, year of trial of labor, and prior vaginal delivery, the odds ratio for uterine rupture in those patients with 2 prior cesarean deliveries was 4.8 (95% confidence interval, 1.8-13. 2) CONCLUSIONS: Women with a history of 2 prior cesarean deliveries have an almost 5-fold greater risk of uterine rupture than those with only 1 prior cesarean delivery.     

Comparison of oral and vaginal misoprostol for induction of labor at term: a randomized controlled trial

OBJECTIVE: To compare the efficacy of oral with vaginal misoprostol for induction of labor at term. METHODS: One hundred and fifty-three pregnant women at term with indications for induction of labor and Bishop score < or = 6 were randomly assigned to receive misoprostol either 100 microg orally or 50 microg vaginally every 6 h for 48 h. Repeated doses were given until Bishop score > or = 8 was achieved or spontaneous rupture of membranes occurred. Those who were not in labor after 48 h had labor induced with amniotomy and oxytocin. The main outcome measure was induction to delivery time. RESULTS: The median induction to vaginal delivery time in the oral group (14.3 h) was not significantly different from that of the vaginal group (15.8 h). The median number of doses was also not significantly different in the oral group compared with the vaginal group. There was a significant higher incidence of uterine tachysystole in the vaginal group compared to the oral group (17.1% vs 5.3%, P = 0.032). There was no hyperstimulation in either group. There were no significant differences between the groups with respect to oxytocin augmentation, cesarean section rate, analgesic requirement, and neonatal outcomes. CONCLUSION: Oral administration of 100 microg misoprostol has similar efficacy to intravaginal administration of 50 microg misoprostol for labor induction with less frequent abnormal uterine contractility. 100 microg of misoprostol orally can be used as an alternative to the vaginal route for labor induction.     

Women's anticipations of and experiences with induction of labor.

BACKGROUND: Although induction of labor is a common procedure, there are limited data on its psychoemotional effects. We studied women's expectations of and experiences with labor induction in a large university hospital. PATIENTS AND METHODS: A total of 296 parturients were recruited, with 270 (91%) taken into the final analysis. Of these, 135 underwent elective induction of labor (44 with amniotomy and 91 with cervical ripening by the use of vaginal prostaglandin gel, followed by amniotomy), whereas the remaining 135 women gave birth spontaneously and served as controls. Each woman was interviewed as to her knowledge, expectations, and feelings about labor before induction or at start of labor (controls) as well as after delivery with the help of questionnaires containing yes/no or multiple-choice questions and visual analog scales. RESULTS: The induction and control groups, in regard to baseline clinical characteristics, did not differ. Labor ended in cesarean section for 24 women in the induction group (18%) and for 12 women in the control group (9%) (p=0.04); these women were included in the data analysis. In the induction group, 67%, and in the control group, 48% of women (p=0.002) reported having received sufficient information on labor induction from medical personnel at prenatal or obstetric clinics. Attitudes towards induction of labor were antenatally positive in 78% of women in the induction group and in 69% in the control group. The induction group reported fear of pain less often (45%) than the control group (57%) (p=0.03). In the induction group, 76 women (56%), and in the control group 94 women (70%) (p=0.02), wanted to participate in the decision on the method of induction, and 74% and 83%, respectively, wished to influence the timing of induction. When interviewed post partum, the labor experience corresponded with the patients' expectations better in the control than in the induction group (p=0.03). Labor induction was a positive experience in 90% of women who underwent immediate amniotomy and in 69% of those who received prostaglandin ripening first. CONCLUSION: Labor induction was a positive experience only seldom eliciting negative feelings. A third of the parturients undergoing induction need more information on the procedure and most want to participate in decision-making concerning the method and timing of induction.     

The sequential use of estradiol and prostaglandin E2 topical gels for cervical ripening in high-risk term pregnancies requiring induction of labor

We compared the safety and efficiency of 200 mg of estradiol valerate prepared as a topical cervical gel as a preripening agent when used 6 hours before the application of 2 mg of prostaglandin E2 gel for the purpose of cervical ripening in 40 high-risk obstetric patients before indicated oxytocin induction of labor. When compared with a placebo prostaglandin E2 dosage, the estradiol had no effect on the change of Bishop score, length of labor, amount of oxytocin required, or the cesarean delivery rate. While no uterine contractions were noted after the application of the estradiol, 85% of patients had recordable uterine activity after the application of prostaglandin E2, suggesting that even at the 2 mg dosage this sequential regimen is not appropriate for local cervical ripening.     

Preinductive cervical ripening with prostaglandin E2 in women with one previous cesarean section.

Thirty term pregnant women with one previous cesarean section and with unripe cervices were given 0.5 mg prostaglandin E2 in gel strictly intracervically for cervical ripening and labor induction. Fifteen out of these 30 women (50%) were vaginally delivered within 24 hours. The cervical ripening/labor induction was considered a failure in two women. In one woman, an episode of hypercontractility was registered. After tocolytic therapy the uterine activity was normalised and the woman had a normal vaginal delivery. The frequency of cesarean sections was 8/30 (27%). At the operations no insufficiencies in the uterine scars were noted. Conclusively, strict intracervical application of 0.5 mg prostaglandin E2 in gel can be used for cervical ripening and labor induction also in women with one previous cesarean section.     

Malpresentations--impact on mode of delivery

Fetal malpresentation, including persistent occipitoposterior position, is a major cause of dystocia resulting in obstetric interventions. We studied malpresentation among 11 957 consecutive singleton deliveries from 1995 to 2004. There were 1 030 deliveries with a malpresentation (8.6%). Cephalic malpresentations occurred in 5.4% of deliveries (persistent occipitoposterior 5.2%, face 0.1%, brow 0.14%), and 3.1% had breech presentation and 0.12% a transverse lie. The odds ratios (OR) for cesarean section were 14.89 (95%CI 11.91-18.63) in breech presentation and 4.57 (95% CI 3.85-5.42) in persistent occipitoposterior presentation. With persistent occipitoposterior position, the OR for instrumental vaginal delivery was 3.84 (95%CI 3.14-4.70). Primiparity was associated with increased malpresentation risks, as 54.6% of those with malpresentations were primiparous compared with 41.7% of those without (OR 1.68, 95%CI 1.48-1.91, p < 0.001). Primiparous women required more cesarean sections (OR 1.92, 95%CI 1.50-2.47) and instrumental deliveries (OR 2.89, 95%CI 1.50-2.47). Malpresentation frequently leads to cesarean section or instrumental delivery, especially among primiparous women.     

Misoprostol versus dinoprostone for cervical priming prior to induction of labour in term pregnancy: a randomised controlled trial

A prospective randomised controlled trial was performed to compare the efficacy and safety of intravaginal misoprostol to that of intravaginal dinoprostone when used for cervical priming prior to the induction of labour; 126 women were recruited to the study and randomised to receive either intravaginal dinoprostone (n = 63) or misoprostol (n = 63) for cervical priming prior to induction of labour. The mean time from insertion of the priming agent to vaginal delivery was significantly shorter in the misoprostol group (925.8 versus 1577.6 minutes), the mean duration of the active length of labour was significantly shorter in the misoprostol group (353.7 versus 496.8 minutes) and more women in the misoprostol group delivered in less than 12 hours (92% versus 76.5%). Women in the misoprostol group were less likely to require a repeated dose of prostaglandin for cervical priming and less likely to require oxytocin for augmentation of labour. There was no difference in the number of women who were delivered vaginally or by Ceasarean section between the two groups. More women developed hyperstimulation during labour in the misoprostol group; however there was no difference between the groups in neonatal outcome in respect to low cord pH or Apgar score at delivery or admission to the neonatal special care nursery.