A randomized trial of laminaria tents versus vaginal misoprostol for cervical ripening in first trimester surgical abortion

OBJECTIVE

To compare the use of laminaria tents with misoprostol for cervical ripening prior to first trimester surgical abortion.

METHOD

In a prospective, open-label, randomized trial, 70 women were assigned to have either insertion of a 3 mm intracervical laminaria tent or vaginal misoprostol 200 microg on the day prior to suction dilatation and curettage (D and C). Cervical dilatation and operating time were measured at the time of D and C; the surgeon subjectively rated the ease of dilatation. The women were interviewed just prior to the D and C with regard to pain, vaginal bleeding, and dilator preference.

RESULTS

Laminaria produced significantly (P < 0.001) greater pre-abortion dilatation of the cervix (34.8 Pratt +/- 6.2) than did misoprostol (28.4 Pratt +/- 5.8). There was no demonstrable difference in ease of dilatation or operating time. Women randomized to use of laminaria reported significantly more pain on insertion than did those who received misoprostol (P < 0.001). Conversely, misoprostol was associated with more vaginal bleeding (P < 0.01). Pain following insertion was similar in each group. Two patients aborted completely after misoprostol alone. Overall, the stated patient preference for cervical dilator was more likely to be misoprostol (P < 0.01).

CONCLUSIONS

Laminaria tents are more effective cervical dilators than vaginal misoprostol when inserted the day prior to suction D and C. Vaginal misoprostol insertion is more comfortable, although it is associated with an increased risk of vaginal bleeding and may abort the pregnancy. Patient preference favours misoprostol. In patient-centred care, both laminaria and misoprostol are suitable options for cervical preparation prior to suction D and C.

A randomized trial comparing a 30-mL and an 80-mL Foley catheter balloon for preinduction cervical ripening

OBJECTIVES

The purpose of this study was to compare the efficacy of cervical ripening with 2 Foley catheter balloon volumes.

STUDY DESIGN

Pregnant women admitted for induction of labor with a term singleton gestation were randomly assigned for cervical ripening by a balloon inflated with 30 mL or 80 mL of sterile saline.

RESULTS

Two hundred and three women were included in the analysis. Ripening of the cervix with the larger balloon volume was associated with a significantly higher rate of post-ripening dilatation of 3 cm or more (76.0% vs 52.4%, P < .001). In primiparous women, the larger balloon volume resulted in a significantly higher rate of deliveries by 24 hours (71.4% vs 49%, P < .05), and a significantly less requirement of augmentation with oxytocin (69.3% vs 90.4%, P < .05).

CONCLUSION

Ripening of the unfavorable cervix in primiparous women with a Foley catheter balloon inflated with 80 mL provided effective more dilatation, faster labor, and decreased need for oxytocin than with a balloon inflated with 30 mL of sterile saline.

Physical and biomechanical characteristics of rat cervical ripening are not consistent with increased collagenase activity

OBJECTIVE

The cervix progressively softens during pregnancy to allow stretch without rupture in labor. Cervical softening is the product of complex modifications that include increased proteoglycan-to-collagen ratio, increased hyaluronic acid and water content, and breakdown of collagen by matrix metalloproteases. The relative contribution of collagen breakdown to cervical ripening is unclear. We sought to identify, discriminate, and quantify the physical characteristics of rat cervix during pregnancy, labor, and both before and after exposure to either prostaglandin (PGE(2)) or the collagenolytic enzyme matrix metalloprotease-1 (MMP-1).

STUDY DESIGN

Cervices were collected from nonpregnant rats in diestrus (n=4) and pregnant rats on d10 (n=4), d16 (n=11), d20 (n=5), and d22 (term) nonlabor (NL: n=4) and d22 in term labor (TL: n=7). Cervices were also collected from a separate group in preterm labor induced by RU486 (PTL: n=10). The effect of PGE(2) on cervical characteristics was determined after intravaginal placement of PGE(2) gel (0.5 mg PGE(2): n=3) or placebo metylcellulose gel (CRL(PG) n=6) for 20 hours before euthanasia on d16. The effect of collagen was determined by incubating in vitro cervices from untreated d16 rats with (MMP-1: n=3) and without (CRL(MMP): n=7) activated collagenase before tensile testing. Tensile properties were quantitated by using Shimadzu EZ-test instrumentation (Shimadzu North America, Columbia, Md) with a stretching regimen that mimicked labor contractions while recording the force opposed by the tissue. Parameters such as the slope (a measure of stiffness), yield point (YP; moment the tissue changes its proprieties from elastic to plastic), and break point (BP; a measure of tissue strength) were recorded and analyzed. The plateau was defined as the phase after YP but before BP.

RESULTS

Compared with d16, cervical extensibility increased significantly by d20 (slope d16: 0.41 +/- 0.03 N/mm vs d20: 0.19 +/- 0.05 N/mm, P < .01), and during both PTL (slope: 0.17 +/- 0.03 N/mm) and TL (slope: 0.11 +/- 0.02 N/mm). This increase was mimicked by PGE(2) (slope PGE(2): 0.24 +/- 0.03 vs CRL(PG): 0.40 +/- 0.05 N/mm, P=.04), but not by collagenase (slope MMP-1: 0.35 +/- 0.02 vs CRL(MMP): 0.38 +/- 0.05 N/mm, P>.05). YP was significantly reduced as pregnancy advanced, whereas BP increased, suggesting both increased plasticity (compliance) and strength. However, the plateau length increased 3-fold both by d20 and after PGE(2). In contrast, the addition of MMP-1 reduced the plateau. BP occurred significantly earlier in collagenase-treated tissues, but later in PTL-, TL-, and PGE(2)-treated cervices.

CONCLUSION

The changes in physical properties of the rat cervix during physiologic ripening are similar to those induced by PGE(2) and RU486, and consist of increased extensibility, compliance, and strength. These changes cannot be attributed to increased collagenase activity, which would decrease tissue compliance and strength.

Buccal or sublingual misoprostol for cervical ripening and induction of labour

BACKGROUND

This is one of a series of reviews of cervical ripening and labour induction using standardised methodology. Misoprostol administered by the oral and sublingual routes have the advantage of rapid onset of action, while the sublingual and vaginal routes have the advantage of prolonged activity and greatest bioavailability.

OBJECTIVES

To determine the effectiveness and safety of misoprostol administered buccally or sublingually for third trimester cervical ripening and induction of labour.

SEARCH STRATEGY

We searched the Cochrane Pregnancy and Childbirth Group trials register (8 December 2003), the Cochrane Central Register of Controlled Trials (The Cochrane Library, Issue 4, 2003), and bibliographies of relevant papers.

SELECTION CRITERIA

Randomised controlled trials comparing buccal or sublingual misoprostol used for third trimester cervical ripening or labour induction with placebo/no treatment or other methods listed above it on a predefined list of labour induction methods.

DATA COLLECTION AND ANALYSIS

A generic strategy was developed to deal with the large volume and complexity of trial data relating to labour induction. Data were extracted onto standardized forms, checked for accuracy, and analysed using RevMan software.

MAIN RESULTS

Three studies (502 participants) compared buccal/sublingual misoprostol respectively with a vaginal regimen (200 microg versus 50 microg) and with oral administration (50 versus 50 microg and 50 versus 100microg).The buccal route was associated with a trend to fewer caesarean sections than with the vaginal route (18/73 versus 28/79; relative risk (RR) 0.70; 95% confidence interval (CI) 0.42 to 1.15). There were no significant differences in any other outcomes. When the same dosage was used sublingually versus orally, the sublingual route was associated with less failures to achieve vaginal delivery within 24 hours (12/50 versus 19/50; RR 0.63, 95% CI 0.34 to 1.16), reduced oxytocin augmentation (17/50 versus 23/50; RR 0.74, 95% CI 0.45 to 1.21) and reduced caesarean section (8/50 versus 15/50; RR 0.53, 95% CI 0.25 to 1.14), but the differences were not statistically significant. When a smaller dose was used sublingually than orally, there were no differences in any of the outcomes.

REVIEWERS' CONCLUSIONS

Based on only three small trials, sublingual misoprostol appears to be at least as effective as when the same dose is administered orally. There are inadequate data to comment on the relative complications and side-effects. Sublingual or buccal misoprostol should not enter clinical use until its safety and optimal dosage have been established by larger trials.

Labor induction in women with an unfavorable Bishop score: randomized controlled trial of intrauterine Foley catheter with concurrent oxytocin infusion versus Foley catheter with extra-amniotic saline infusion with concurrent oxytocin infusion

OBJECTIVES

This study was undertaken to determine whether the addition of extra-amniotic saline infusion improves the efficacy of the Foley catheter in women undergoing cervical ripening and induction of labor with an unfavorable cervical examination.

STUDY DESIGN

One hundred consenting women with a Bishop score less than 5 with singleton gestation, intact membranes, vertex presentation, who required induction of labor were randomly assigned to 2 groups: Foley alone (Foley, n=49) or to the Foley catheter with extra-amniotic saline infusion (EASI, 30 mL of NS per hour infused through the distal port of the Foley, n=51). All women received concurrent dilute oxytocin infusion per protocol. The primary analysis was intent to treat. Nonparametric tests were used as indicated.

RESULTS

At randomization, the groups were well balanced for potential confounders including: parity, gestational age, prior cesarean delivery, preeclampsia, mean dilation, effacement, and Bishop score. There were no differences between the groups for time to delivery (Foley 17.7 +/- 10.5 hours vs EASI 17.4 +/- 11.7 hours, P=.9), the proportion of women delivered before 24 hours (Foley 41/49 [84%] vs EASI 39/51 [77%], P=.37) or cesarean rates (Foley 9/49 [17.7%] vs EASI 9/51 [18.4%], P=.92). There were also no differences in complications, including chorioamnionitis, endometritis, and neonatal morbidity.

CONCLUSION

EASI does not increase the efficacy of cervical ripening and induction of labor with a Foley catheter and concurrent oxytocin infusion.

Increased rates of chorioamnionitis with extra-amniotic saline infusion method of labor induction

OBJECTIVE

Extra-amniotic saline infusion has been shown to be equal to or more efficacious than misoprostol, laminaria, dinoprostone, and prostaglandin estradiol for cervical ripening and labor induction. Because of the introduction of a foreign body into the uterus, extra-amniotic saline infusion may potentially cause increased rates of chorioamnionitis. This study examines the risk of chorioamnionitis with extra-amniotic saline infusion compared with other methods of induction and spontaneous labor.

METHODS

A retrospective analysis was performed based on deliveries at Bellevue Hospital Center, a tertiary-care facility, from August 2000 to December 2002. Three groups were identified: extra-amniotic saline infusion, other methods of induction, and spontaneous labor. Differences in chorioamnionitis rates were analyzed by using analysis of variance and multivariable logistic regression as appropriate.

RESULTS

There were 625 charts evaluated: 171 extra-amniotic saline infusion, 190 other, and 264 with spontaneous labor. The rates of chorioamnionitis were 26.9%, 17.9%, and 13.3%, respectively. After adjusting for confounding variables, such as instrumentation, length of rupture, and number of exams, subjects who were induced with extra-amniotic saline infusion were significantly more likely to develop chorioamnionitis (relative risk = 2.2; 95% confidence interval 1.4, 4.0; P =.006).

CONCLUSION

Extra-amniotic saline infusion may be associated with a greater risk of chorioamnionitis when compared with other methods of labor induction. Given the increased risk of chorioamnionitis associated with extra-amniotic saline infusion, its use should be in the context of a careful assessment of the risks and benefits of various methods of labor induction.

LEVEL OF EVIDENCE

II-2

Uterine rupture in patients with a prior cesarean delivery: the impact of cervical ripening

The purpose of this study was to examine factors that were associated with uterine rupture in patients attempting vaginal birth after cesarean delivery. We analyzed the results of all patients attempting vaginal birth after cesarean delivery between September 1996 to December 1999 at a single institution using a contemporaneously maintained registry. Maternal factors, fetal factors, and management of labor were all assessed to determine the risk factors associated with symptomatic uterine rupture at the time of attempted vaginal birth after cesarean delivery. Twenty-eight symptomatic ruptures were identified in 972 attempts of vaginal birth after cesarean delivery at a gestational age greater than 24 weeks (2.88%). The use of preinduction cervical ripening was significantly associated with an increased risk of symptomatic uterine rupture (odds ratio, 3.92; 95% confidence interval, 1.78 to 8.62). Patients who underwent preinduction cervical ripening were significantly less likely to delivery vaginally than women who had not (46.71 versus 76.87%; p < 0.001). No other differences were noted between the two groups. Preinduction cervical ripening is associated with an increased risk of uterine rupture in women attempting vaginal birth after cesarean delivery.

Preinduction cervical ripening with the Foley catheter and the risk of subsequent preterm birth

OBJECTIVE

The Foley catheter is a safe and effective form of preinduction cervical ripening and is quickly growing in popularity. Its major effect appears to be through mechanical dilation, which has raised the concern that the use of the Foley catheter for cervical ripening may damage the cervix and result in a higher rate of subsequent preterm birth.

STUDY DESIGN

We conducted a review of all induction of labor at our institution from July 1998 to July 2001 that required preinduction cervical ripening and had a subsequent birth. The primary outcome variable was preterm birth at <35 weeks of gestation. Demographic and potential confounding variables were analyzed. A probability value of <.05 was considered significant.

RESULTS

The cases of 126 women (63 women in the Foley group and 63 women in the prostaglandin group) were studied. Women in the prostaglandin group had a prostaglandin agent used. There was no difference in maternal age, gravidity, parity, Bishop score, total time of induction, gestational age, oxytocin use, maximum oxytocin level, tobacco or drug use, or type of delivery in the index pregnancy between the groups. In the subsequent pregnancies, there were no differences in maternal age, gravidity, parity, spontaneous abortions, terminations, cone or Loop Electrosurgical Excision Procedure (LEEP) procedures, history of cervical manipulation, tobacco or drug use, stillbirth, need for induction, mode of delivery, episiotomy, gestational age at delivery, Apgar scores, labor duration, use of oxytocin, or birth weight. There were no differences in preterm birth at 37, 35, or 32 weeks of gestation between the groups.

CONCLUSION

The use of the Foley catheter for preinduction cervical ripening does not appear to increase the risk of preterm birth in a subsequent pregnancy.

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.

Effectiveness and infectious morbidity of outpatient cervical ripening with a Foley catheter

OBJECTIVE

To assess the effectiveness and infectious morbidity of outpatient cervical ripening with a Foley catheter.

STUDY DESIGN

Labor inductions utilizing a Foley catheter for cervical ripening from January 1994 to October 1999 were retrospectively reviewed. The inductions were divided into inpatient and outpatient groups. Vaginal delivery rates and infectious morbidity were compared between the 2 groups.

RESULTS

There were 315 inpatient and 300 outpatient cases. The observed differences in vaginal delivery rates and infectious morbidity were not clinically or statistically significant. However, there was insufficient power to exclude a type II error. The cost savings was $165,000, and there is the potential to save $750 per patient with this method.

CONCLUSION

Outpatient cervical ripening with a Foley catheter is clinically effective, does not result in excess infectious morbidity and is more cost effective as compared to inpatient cervical ripening.

Randomized Trial of Intracervical Versus Posterior Fornix Dinoprostone for Induction of Labor

OBJECTIVE

To investigate whether intracervical placement of a sustained-release dinoprostone insert decreased the length of time to delivery when compared with placement in the posterior fornix.

METHODS

Sixty-three patients were randomized to intracervical (n = 33) or posterior fornix (n = 30) placement of the initial dose. Dinoprostone was placed under direct visualization with a vaginal speculum and packing forceps. The patients and staff were blinded to the site of placement. Multiple end points were examined throughout labor. Student t test, Fisher exact test, Wilcoxon test, Mann-Whitney U test, and chi2 analyses were performed when appropriate. A P value of less than.05 was considered significant.

RESULTS

Forty-six patients who required only a single dose of dinoprostone had a reduced time to delivery with intracervical (n = 24; 11.70 hours) compared with intravaginal (n = 22; 16.20 hours) placement (P =.025). There was also a reduced time to active labor (intracervical = 8.25 hours, posterior fornix = 11.50 hours; P =.083), ruptured membranes (intracervical = 10.25 hours, posterior fornix = 12.00 hours; P =.047), and request for initial pain medications (intracervical = 5.00 hours, posterior fornix = 11.25 hours; P =.025) with intracervical placement. There was no difference in number of patients managed with artificial rupture of membranes. There was no difference in maternal age, race, parity, maternal height or weight, or indication for induction. There was also no difference in cesarean delivery rate, antepartum fever, hyperstimulation, Apgar scores, birth weight, or umbilical artery pH.

CONCLUSION

In patients who respond to a single sustained-release dinoprostone insert, intracervical placement decreases time to delivery without increasing the cesarean delivery rate, infectious morbidity, or other complications of labor.

Comparison between the sublingual and oral route of misoprostol for pre-abortion cervical priming in first trimester abortions

BACKGROUND

Misoprostol has been used for achieving cervical priming before suction evacuation (SE) by the oral or vaginal route, although both routes have their shortcomings. We evaluated the efficacy of the sublingual versus oral route of misoprostol for cervical priming before SE.

METHODS

A prospective clinical trial was carried out in 100 women with a period of gestation of between 6 and 12 weeks who were sequentially allocated to two groups of 50 each. Both groups received 400 microg of misoprostol 3 h prior to SE by either the sublingual or the oral route.

RESULTS

Demographically, both groups were similar. For all periods of gestation, sublingual misoprostol significantly improved cervical dilation (P<0.001) with a reduction in duration of surgery (P=0.024) compared with the oral route. Mean (+/- SD) pain scores for the sublingual and oral groups were similar (2.6 +/- 1.4 versus 3.5 +/- 1.1). No major complications occurred in either of the two groups.

CONCLUSION

the sublingual route is an effective alternative to oral administration of misoprostol for cervical dilation. To the best of our knowledge, this is the first study to compare the efficacy of the sublingual versus the oral route of misoprostol for cervical priming before SE.

Acupuncture for induction of labour

BACKGROUND

This is one of a series of reviews of methods of cervical ripening and labour induction using standardised methodology. The use of complementary therapies is increasing and some women look to complementary therapies during pregnancy and childbirth to be used alongside conventional medical practice. Acupuncture involves the insertion of very fine needles into specific points of the body. The limited observational studies to date suggest acupuncture for induction of labour appears safe, has no known teratogenic effects, and may be effective. The evidence regarding the clinical effectiveness of this technique is limited.

OBJECTIVES

To determine the effects of acupuncture for third trimester cervical ripening or induction of labour.

SEARCH STRATEGY

The Cochrane Pregnancy and Childbirth Group trials register (February 2003), the Cochrane Central Register of Controlled Trials (The Cochrane Library, Issue 1, 2003), PubMed (1966 to present), CISCOM (1960 to present), EMBASE (1980 to present) and bibliographies of relevant papers.

SELECTION CRITERIA

Clinical trials comparing acupuncture used for third trimester cervical ripening or labour induction with placebo/no treatment or other methods listed above it on a predefined list of labour induction methods.

DATA COLLECTION AND ANALYSIS

A strategy was developed to deal with the large volume and complexity of trial data relating to labour induction. This involved a two-stage method of data extraction.

MAIN RESULTS

One trial of 56 women was included in the review. Data were not in a form that could be included in the meta-analysis.

REVIEWER'S CONCLUSIONS

There is a need for well-designed randomised controlled trials to evaluate the role of acupuncture to induce labour and for trials to assess clinically meaningful outcomes.

A randomized controlled comparison of sublingual and vaginal administration of misoprostol for cervical priming before first-trimester surgical abortion

OBJECTIVE

The purpose of this study was to compare the effectiveness of the sublingual and vaginal administration of misoprostol for cervical priming before surgical termination of pregnancy.

STUDY DESIGN

In a randomized controlled trial, 74 primigravid women who were undergoing surgical abortion were assigned randomly to receive misoprostol (400 microg) sublingually or vaginally.

RESULTS

There was no statistically significant difference in the cumulative force that was required to dilate the cervix to 9 mm, for baseline cervical dilatation, for priming to abortion interval, for operating time, or for intraoperative blood loss between the two groups. Women in the sublingual group had more nausea (P=.008), vomiting (P=.01), diarrhea (P=.01), and unpleasant mouth taste (P=.0001) compared with the women in the vaginal group. In the sublingual group, 65% of women were satisfied with the route of misoprostol administration compared with 78% in the vaginal group (P=.11). Most of the staff members (84%) said that they would recommend the sublingual administration of misoprostol (P=.0001).

CONCLUSION

The sublingual administration of misoprostol is an effective alternative to vaginal administration for cervical priming before surgical abortion; despite a higher incidence of side effects, there was high patient and staff acceptability.

[Cervical maturation in post-term pregnancy: prostaglandin E2 versus Foley probe]

To compare two methods of cervical maturation in frame of labor induction the case of overtaking of term. Study review compare two groups, first group is to form of 51 patients having had one cervical maturation by gel of predipil, second in compound of 63 patients having benefited of one maturation cervical by one probe of Foley. The entrance spontaneous in labor later administration cervical of gel of prostaglandin is of 45% against 8% only in-group of patients having had one maturation by probe of foley. Duration of labor is more short in first group. Probe Foley countered so effective that gel of prostaglandin it appears as one method of cervical maturation of choice in our environment.

[Current practice and results of labor induction]

INTRODUCTION

The role of labor induction has been gradually increasing in the last decade all over Europe due to the early detection of fetal jeopardy, improvement of neonatal therapy and availability of cervical ripening agents. Success rate of vaginal delivery depends on maternal, fetal condition and cervical status.

PATIENTS

Authors report the outcome of 795 labor inductions during the period from 1996 to 2000 at the Department of Obstetrics and Gynecology at the University of Debrecen, Hungary. Preinduction cervical ripening and induction method was based on Bishop score and clinical situation.

RESULTS

The rate of induced labor was 5.97% out of 13312 consecutive deliveries. The outcome of induction is discussed in details. The caesarean section rate after induction of vaginal delivery was 25% in this high risk group, and 33.3% among the total number of inductions.

CONCLUSIONS

The clinical application of prostaglandins for cervical ripening among high risk pregnant women facilitates the decision of labor induction and provides a favourable rate of vaginal deliveries.

A study of the efficacy of cervical ripening with nitric oxide donor versus placebo for cervical priming before second-trimester termination of pregnancy

This was a double-blind randomized control study to evaluate the efficacy of cervical priming by nitric oxide donor before second-trimester induced abortion. One-hundred healthy women with a singleton pregnancy between 14 and 20 weeks of gestation were randomized into either 40 mg isosorbide mononitrate or placebo, given intravaginally 12 h before induction. This was followed by intravaginal misoprostol induction. The induction-abortion interval, abortion rate, side effects and the woman's acceptability of the priming agent were recorded. All women completed the study and there was no severe complication recorded. There was no significant difference in the induction-abortion interval and abortion rate between the two groups. Isosorbide mononitrate group reported significantly more side effects of headache. More than 90% of the women in both groups found the priming agent acceptable. The application of intravaginal nitric oxide donors prior to the prostaglandins induction did not significantly improve the second-trimester induced-abortion process.

Induction of labour with a favourable cervix and/or pre-labour rupture of membranes

Premature rupture of membranes (PROM) occurs in 8% of term deliveries. In this situation labour induction with prostaglandins, compared with expectant management, results in a reduced risk of chorioamnionitis, neonatal antibiotic therapy, neonatal intensive care (NICU) admission, and increased maternal satisfaction. The use of prostaglandin is associated with an increased rate of diarrhoea and use of analgesia/anaesthesia. Compared with oxytocin, prostaglandin induction results in a lower rate of epidural use and internal fetal heart rate monitoring but a greater risk of chorioamnionitis, nausea, vomiting, more vaginal examinations, neonatal antibiotic therapy, NICU admission and neonatal infection. Women should be informed of the risks and benefits of each method of induction.Misoprostol is gaining increasing interest as an alternative induction agent. It appears to be an effective method of labour induction with term PROM. Further research is needed to identify the preferred dosage, route and interval of administration, and to assess uncommon maternal and neonatal outcomes. There has been limited research on the use of prostaglandins, including misoprostol, for induction of labour with a favourable cervix and intact membranes. Compared with intravenous oxytocin (with and without amniotomy), labour induction using vaginal prostaglandins in women with a favourable cervix (with and without PROM) results in a higher rate of vaginal delivery within 24 hours and increased maternal satisfaction. In women with a favourable cervix, artificial rupture of membranes followed by oral misoprostol has similar time to vaginal delivery compared with artificial rupture of membranes followed by oxytocin. Further research with prostaglandins, including misoprostol, is needed to evaluate other maternal and neonatal outcomes in women being induced with a favourable cervix. No form of prostaglandin induction in women with PROM or favourable cervix has proven clearly superior to oxytocin infusion.

Induction of labour with an unfavourable cervix

Labour induction is undertaken when the advantages for the mother and/or the baby are considered to outweigh the disadvantages. When the uterine cervix is unfavourable, oxytocin, with or without amniotomy, is frequently ineffective. Vaginal prostaglandin E(2) is most commonly used if it is affordable. Evidence regarding many alternative methods is discussed in this chapter. Of particular interest are misoprostol and extra-amniotic saline infusion.Misoprostol, an orally active prostaglandin E(1) analogue, has been used widely by the vaginal and oral routes for labour induction at or near term. Several recent trials have confirmed that it is highly effective. Overall Caesarean section rates appear to be reduced, despite a relative increase in Caesarean sections for fetal heart rate abnormalities. Concern remains regarding increased rates of uterine hyperstimulation and meconium-stained amniotic fluid, although data on perinatal outcome have been reassuring. Postpartum haemorrhage may be increased following labour induction with misoprostol, and isolated reports of uterine rupture, with or without previous Caesarean section, have appeared. Using small dosages appears to reduce adverse outcomes. Very large trials are needed to evaluate rare adverse outcomes.Extra-amniotic saline infusion is an effective method which appears to reduce the risk of uterine hyperstimulation that occurs with the use of exogenous uterotonics.

The MisoPROM study: A multicenter randomized comparison of oral misoprostol and oxytocin for premature rupture of membranes at term

OBJECTIVE

This study was undertaken to determine whether induction of labor with oral misoprostol will result in fewer cesarean deliveries than intravenous oxytocin in nulliparous women with premature rupture of membranes at term.

STUDY DESIGN

Three hundred five women at 10 centers were randomly assigned to receive oral misoprostol, 100 microg every 6 hours to a maximum of two doses or intravenous oxytocin. The primary outcome measure was cesarean deliveries. Secondary outcomes were time from induction to vaginal delivery and measures of maternal and neonatal safety.

RESULTS

The study was stopped prematurely because of recruitment difficulties. We present the results for the 305 enrolled women. There was no difference in the proportion of women who underwent cesarean delivery (20.1% in the misoprostol group, 19.9% in the oxytocin group). The time interval from induction to vaginal delivery was also similar (11.9 hours for the misoprostol group, and 11.8 hours for the oxytocin group). Maternal and neonatal safety outcomes were similar for the two treatments. More infants born to women in the misoprostol group received intravenous antibiotics in the neonatal period (16.4% vs 6.9%, P=.01), although there were no differences in chorioamnionitis or in proven neonatal infections. Women receiving misoprostol were less likely to have postpartum hemorrhage than those receiving oxytocin (1.9% vs 6.2%, P=.05).

CONCLUSION

Oral misoprostol does not offer any advantage in time from induction to vaginal delivery or risk of cesarean section.

Prostaglandins for first-trimester termination

Since the 1980s, when mifepristone combined with a prostaglandin was found to be safe and effective for early abortion, many studies have refined the regimens and investigated alternatives such as methotrexate plus misoprostol, and misoprostol alone. Evidence now demonstrates that more than 200 mg of mifepristone provides no additional benefit, that vaginal misoprostol is superior to oral, especially between 7 and 9 weeks' gestation, and that misoprostol may be safely self-administered at home. Buccal and sublingual routes of administration of misoprostol also are promising. Absolute contraindications to medical abortion arise infrequently. Gastrointestinal and other side-effects occur in about one-third of women, primarily after administration of the prostaglandin. Careful assessment before and after medical abortion is essential and can be accomplished in various ways, depending on the skills of the clinician.

Prostaglandins for induction of second-trimester termination and intrauterine death

The introduction of synthetic prostaglandin has revolutionized the treatment protocol for induction of second-trimester abortion and intrauterine death. Gemeprost is the only licensed synthetic prostaglandin analogue for second-trimester abortion in the United Kingdom. However, it is expensive and needs to be stored in a refrigerator. Misoprostol is marketed for use in the prevention and treatment of peptic ulcer. It is inexpensive and can be stored at room temperature. It has been widely used for induction of second-trimester abortion and intrauterine death. Misoprostol, 400 microg given vaginally every 3hours, is probably the optimal regimen for second-trimester abortion. The combination of misoprostol and mifepristone significantly reduced the induction-to-abortion interval when compared with the misoprostol-only regimen. In addition, misoprostol can also be used as a cervical priming agent prior to dilatation and evacuation in second-trimester abortion.

Gemeprost versus misoprostol for cervical priming before first-trimester abortion: a randomized controlled trial

OBJECTIVE

To compare the efficacy of 400 microg of misoprostol with that of 1 mg of gemeprost as cervical priming agents when administered vaginally 3 to 4 hours before first-trimester vacuum aspiration abortion.

METHODS

In a prospective controlled trial 90 nulliparous women who requested termination of pregnancy before 12 weeks' gestation were randomized to receive vaginally either misoprostol or gemeprost for cervical priming. The force to dilate the cervix was measured by the use of a cervical tonometer connected to Hegar dilators from 3 to 10 mm. The main outcome measures were baseline cervical dilation; the peak force to dilate the cervix at 8, 9, and 10 mm; and the cumulative force to dilate the cervix to 10 mm.

RESULTS

Baseline cervical dilation did not differ significantly between the women who received misoprostol and those who were treated with gemeprost. Neither the peak force required to dilate the cervix at 8, 9, and 10 mm nor the cumulative force to dilate the cervix to 10 mm showed any significant difference between the two groups.

CONCLUSION

Vaginally administered misoprostol (400 microg) is as effective as gemeprost (1 mg) for cervical priming 3 to 4 hours before surgical termination of first-trimester pregnancies.

Comparative efficacy and cost of the prostaglandin analogs dinoprostone and misoprostol as labor preinduction agents

OBJECTIVE

The purpose of this study was to compare the relative efficacy and cost of three commercially available prostaglandin analogs, misoprostol (Cytotec), dinoprostone gel (Prepidil), and dinoprostone insert (Cervidil), as labor preinduction agents.

STUDY DESIGN

One-hundred eleven women with an unfavorable cervix who underwent labor induction were assigned randomly to receive either misoprostol 50 microg every 6 hours for two doses, dinoprostone gel 0.5 mg every 6 hours for two doses, or dinoprostone insert 10 mg for one dose intravaginally. Twelve hours later, oxytocin induction was initiated per standardized protocol. Efficacy and cost of the labor preinduction/induction with the study treatments were compared.

RESULTS

Mean Bishop score change (+/-SD) over the initial 12-hour interval was significantly greater in the misoprostol group (5.2 +/- 3.1) compared with the dinoprostone insert (3.2 +/- 2.3) or the dinoprostone gel groups (2.2 +/- 1.3, P <.0001). The proportion of women who reached complete dilation (68.4%, 50.0%, 51.4%, respectively; P =.14) and who were delivered (60.5%, 47.4%, 40.0%, respectively; P =.10) within 24 hours of the initiation of induction were not significantly different between the misoprostol, dinoprostone insert, and dinoprostone gel groups. Induction-to-delivery intervals, however, were significantly shorter among women who treated with misoprostol (24.0 +/- 10.8 hours) compared with either the dinoprostone gel (31.6 +/- 13.4 hours) or the dinoprostone insert (32.2 +/- 14.7 hours, P <.05). Overall mean cost per patient that was incurred by labor induction was significantly less for the misoprostol group ($1036.13) compared with the dinoprostone insert group ($1565.72) or the dinoprostone gel group ($1572.92, P <.0001). No significant differences were noted with respect to the mode of delivery or to the adverse maternal/neonatal outcome.

CONCLUSION

Misoprostol is more cost-effective than the comparable commercial dinoprostone prostaglandin preparations as an adjuvant to labor induction in women with an unfavorable cervix.

Vaginal misoprostol for cervical ripening and induction of labour

BACKGROUND

Misoprostol (Cytotec, Searle) is a prostaglandin E1 analogue marketed for use in the prevention and treatment of peptic ulcer disease. It is inexpensive, easily stored at room temperature and has few systemic side effects. It is rapidly absorbed orally and vaginally. Although not registered for such use, misoprostol has been widely used for obstetric and gynaecological indications, such as induction of abortion and of labour. This is one of a series of reviews of methods of cervical ripening and labour induction using standardised methodology.

OBJECTIVES

To determine the effects of vaginal misoprostol for third trimester cervical ripening or induction of labour.

SEARCH STRATEGY

The Cochrane Pregnancy and Childbirth Group trials register (October 2002), the Cochrane Controlled Trials Register (The Cochrane Library, Issue 3, 2002) and bibliographies of relevant papers.

SELECTION CRITERIA

The criteria for inclusion included the following: (1) clinical trials comparing vaginal misoprostol used for third trimester cervical ripening or labour induction with placebo/no treatment or other methods listed above it on a predefined list of labour induction methods; (2) random allocation to the treatment or control group; (3) adequate allocation concealment; (4) violations of allocated management not sufficient to materially affect conclusions; (5) clinically meaningful outcome measures reported; (6) data available for analysis according to the random allocation; (7) missing data insufficient to materially affect the conclusions.

DATA COLLECTION AND ANALYSIS

A strategy was developed to deal with the large volume and complexity of trial data relating to labour induction. This involved a two-stage method of data extraction. The initial data extraction was done centrally, and incorporated into a series of primary reviews arranged by methods of induction of labour, following a standardised methodology. The data will be extracted from the primary reviews into a series of secondary reviews, arranged by category of woman. To avoid duplication of data in the primary reviews, the labour induction methods have been listed in a specific order, from one to 25. Each primary review includes comparisons between one of the methods (from two to 25) with only those methods above it on the list.

MAIN RESULTS

Sixty-two trials have been included. Compared to placebo, misoprostol was associated with increased cervical ripening (relative risk of unfavourable or unchanged cervix after 12 to 24 hours with misoprostol 0.09, 95% confidence interval (CI) 0.03 to 0.24). It was also associated with reduced failure to achieve vaginal delivery within 24 hours (relative risk (RR) 0.36, 95% CI 0.19 to 0.68). Uterine hyperstimulation, without fetal heart rate changes, was increased (RR 11.7 95% CI 2.78 to 49). Compared with vaginal prostaglandin E2, intracervical prostaglandin E2 and oxytocin, vaginal misoprostol labour induction was associated with less epidural analgesia use, fewer failures to achieve vaginal delivery within 24 hours and more uterine hyperstimulation. Compared with vaginal or intracervical prostaglandin E2, oxytocin augmentation was less common, with misoprostol and meconium-stained liquor more common. Compared with intracervical prostaglandin E2, unchanged or unfavourable cervix after 12 to 24 hours was less common with misoprostol. Lower doses of misoprostol compared to higher doses were associated with more need for oxytocin augmentation, less uterine hyperstimulation, with and without fetal heart rate changes, and a non-significant trend to fewer admissions to neonatal intensive care unit. Use of a gel preparation of misoprostol versus tablet was associated with less hyperstimulation and more use of oxytocin and epidural analgesia. Information on women's views is conspicuously lacking.

REVIEWER'S CONCLUSIONS

Vaginal misoprostol appears to be more effective than conventional methods of cervical ripening and labour induction. The apparent increase in uterine hyperstimulation is of concern. Doses not exceeding 25 mcg four-hourly of concern. Doses not exceeding 25 mcg four-hourly appeared to have similar effectiveness and risk of uterine hyperstimulation to conventional labour inducing methods. The studies reviewed were not large enough to exclude the possibility of rare but serious adverse events, particularly uterine rupture, which has been reported anecdotally following misoprostol use in women with and without previous caesarean section. The authors request information on cases of uterine rupture known to readers. Further research is needed to establish the ideal route of administration and dosage, and safety. Professional and governmental bodies should agree guidelines for the use of misoprostol, based on the best available evidence and local circumstances.

Obstructed labour

Obstructed labour is an important cause of maternal deaths in communities in which undernutrition in childhood is common resulting in small pelves in women, and in which there is no easy access to functioning health facilities with the capability of carrying out operative deliveries. Obstructed labour also causes significant maternal morbidity in the short term (notably infection) and long term (notably obstetric fistulas). Fetal death from asphyxia is also common. There are differences in the behaviour of the uterus during obstructed labour, depending on whether the woman has delivered previously. The pattern in primigravid women (typically diminishing contractility with risk of infection and fistula) may result from tissue acidosis, whereas in parous women, contractility may be maintained with the risk of uterine rupture. Ultimately, tackling the problem of obstructed labour will require universal adequate nutritional intake from childhood and the ability to access adequately equipped and staffed clinical facilities when problems arise in labour. These seem still rather distant aspirations. In the meantime, strategies should be implemented to encourage early recognition of prolonged labour and appropriate clinical responses. The sequelae of obstructed labour can be an enormous source of human misery and the prevention of obstetric fistulas, and skilled treatment if they do occur, are important priorities in regions where obstructed labour is still common.

Cervical ripening: how long can the Foley catheter safely remain in the cervical canal?

This was a prospective study involving 85 patients admitted for induction of labour with unfavourable cervix at Usman Danfodiyo University Teaching Hospital, Sokoto, Nigeria. A size 16-20 Foley catheter was passed transcervically into the extra-amniotic space under aseptic technique and the balloon inflated with 30-50 mls sterile water. Each patient was placed on prophylactic antibiotics. The balloon was expelled within 12 hours in 22 (39%) patients. Twenty eight patients expelled the balloon in 12-24 hours, 14 in 25-48 hours, 6 in 49-72 hours and 4 after 72 hours. The average duration of catheter placement when the gestational age was 20-27 weeks was 44.8 hours, which was significantly longer than 19.6 hours obtained for term pregnancies (p < 0.05). Induction of labour was successful in 77 (91%) patients and there was no significant maternal morbidity. The results of our study suggest that the balloon of the Foley catheter can safely remain in the extra-amniotic space longer than 24 hours for cervical ripening if the cervix is unfavourable, provided the membranes are intact and the feto-maternal conditions remain satisfactory.

[Comparison study on transvaginal ultrasonographic measurement and cytokine in prediction of the cervical ripening and the onset time of term labor]

OBJECTIVE

To compare the level of interleukin-6 (IL-6), interleukin-8 (IL-8), human chorionic gonadotropin (hCG) with transvaginal ultrasonographic measurement in prediction of the cervix ripening and the time of term labor.

METHODS

The 79 cases of primiparous women of term pregnancy were chosen as the research subjects. The maternal level of IL-6, IL-8, hCG in cervicovaginal secretions were measured. The cervical length, internal cervical os wedge width and forebag length were measured by transvaginal ultrasonography. The cervical Bishop score was also determined.

RESULTS

(1) The levels of IL-6, IL-8, hCG in cervicovaginal secretions were significantly higher in women they are in labor than that of women at term not in labor (782 +/- 508) ng/L, (10,539 +/- 8 680) ng/L, (114 +/- 86) IU/L, versus (155 +/- 75) ng/L, (7,113 +/- 6 050) ng/L, (35 +/- 21) IU/L, respectively. (2) The levels of cervicovaginal secretions IL-6, IL-8, hCG and the length of cervical, forebag were significant correlation with the cervical Bishop score (P < 0.05, r = 0.42, 0.24, 0.44, -0.56, 0.35) respectively. (3) The levels of cervicovaginal secretions IL-6, IL-8, the length of cervical, forebag measured by transvaginal ultrasonography and the cervical Bishop score were significant correlation to the onset time of term labor (P < 0.01, r = -0.42, -0.46, 0.64, -0.52, -0.41) respectively, and all these markers also could predict the onset of term labor in < or = 7 days, The predictive value on onset labor within < or = 7 days by cervical length < or = 30 mm: the sensitivity, specificity, positive values and negative value are 0.83, 0.89, 0.91 and 0.81 respectively. (4) Among the several markers in predicting cervix ripening and onset of labor, the best one was the transvaginal ultrasonographic measurement of cervical length.

CONCLUSIONS

The levels of cervicovaginal secretions IL-6, IL-8, the length of cervical and forebag measured by transvaginal ultrasonography and the Bishop score are valuable in prediction of cervix ripening and onset of labor. The cervical length measured by transvaginal ultrasonography is the best one.

Elective induction: an analysis of economic and health consequences

OBJECTIVE

Our purpose was to assess economic and health consequences of elective induction at term.

STUDY DESIGN

A decision-tree model incorporating a Markov analysis was used to compare the decision either to electively induce labor at term or expectantly manage the pregnancy until 42 weeks' gestation. Main outcome measures, stratified by parity, cervical ripeness, and gestational age at induction, were number of cesarean deliveries and costs to the health care system.

RESULTS

By use of baseline estimates, induction at any gestational age, regardless of parity and cervical ripeness, required expenditures from the medical system. Although never cost saving, inductions were less expensive at later gestational ages, for multiparous patients, and for those women with a favorable cervix. Sensitivity analysis demonstrated a robust model.

CONCLUSIONS

Elective induction of labor at term is not cost saving and results in a large excess of cesarean deliveries. Costs are significantly altered by the timing of the induction, parity, and cervical ripeness.

Pre-term cervical ripening and labor induction

OBJECTIVE

To evaluate retrospectively pre-term induction; with Prostaglandin (PG) E(2)-gel and i.v. oxtytocin, respectively.

METHODS

Fifty pre-term women with a gestational age between 28 + 0 and 36 + 6 and medical indications for labor induction were compared with the two next induced at term and post-term. The obstetric end points were numbers of PGE(2)-gel applications, failed inductions, instrumental delivery and heavy bleeding after partus (>1000 ml). The neonatal outcome was registered as operative delivery for fetal distress (ODFD) or Apgar score <7 at 5'.

RESULTS

The number of PGE(2)-gel applications did not differ. The duration of labor was shorter in the pre-term group (P = 0.043). A five-fold higher risk of heavy postpartum bleeding (>1000 ml) was noticed in the post-term group compared to the pre-term. The incidence of low Apgar scores were similar in the three groups.

CONCLUSIONS

Safe vaginal labor induction and delivery can be anticipated pre-term with PGE(2)-gel.

Does preterm cervical dilatation imply imminent labor in multifetal pregnancies?

OBJECTIVE

Women with multifetal pregnancies are at increased risk of preterm labor and delivery compared with singleton pregnancies. Presentation with advanced cervical dilatation of 3-4 cm is generally regarded as being in the midst of the first stage of labor. The purpose of this report is to present our experience in cases of advanced cervical dilatation and arrested preterm labor in multifetal pregnancies.

METHODS

This study is a retrospective analysis of threatened preterm deliveries in women with multifetal pregnancies. Fifteen cases with advanced cervical dilatation that remained undelivered for at least 10 days are presented and reviewed.

RESULTS

Out of 1219 women presenting with multifetal pregnancies to the high-risk maternity unit, 15 women who presented with advanced cervical dilatation of 3-5 cm and remained undelivered for at least 10 days were identified. Eight women presented with twins and seven with triplets. The mean latency period to delivery was 21.7 days (range 10-43 days). The mean gestational age at diagnosis was 31.3 weeks (range 26.3-35.3 weeks). The mean gestational age at delivery was 34.5 weeks (range 29.5-38.0 weeks). Twelve women delivered vaginally in this group, giving a cesarean section rate of 20%.

CONCLUSIONS

In the women presented in this series advanced cervical dilatation did not lead directly to preterm labor and delivery, we believe due to their having a multifetal gestation. It is possible that dilatation of the cervix in these cases is not a result of preterm labor but rather a relative cervical incompetence resulting from overdistention of the uterus in twins or higher-order gestations. This phenomenon may be underdiagnosed because of a tendency to forego frequent digital examinations remote from term without a clear indication. More information is therefore needed on the mechanism of cervical change during multifetal pregnancy.

Ripening of the uterine cervix in a post-cesarean parturient: prostaglandin E2 versus Foley catheter

OBJECTIVE

To compare the success and complication rates of prostaglandin E2 tablets (PGE2) and a Foley catheter for the ripening of the uterine cervix in post-Cesarean section parturients.

STUDY DESIGN

The study population in this retrospective cohort study consisted of parturients in their second pregnancy who had undergone Cesarean section in their previous delivery and who underwent ripening of the uterine cervix by using PGE2 (n = 55) or Foley catheter (n = 161) in the current pregnancy. The control group consisted of 1432 post-Cesarean section parturients without induction of labor. We compared the rates of placental abruption, non-reassuring fetal heart rate patterns, intrapartum fetal deaths (IPFD), uterine rupture, Apgar scores, labor dystocia, severe birth canal lacerations, vacuum deliveries and repeated Cesarean section rates in the three groups by using ANOVA, chi2 analysis and Fisher's exact test when appropriate.

RESULTS

A significant increase in the rates of labor dystocia during the first stage (30.4% vs. 11.6%, p < 0.01) and repeated Cesarean deliveries (49.1% vs. 35.2%, p < 0.01) were observed in women in whom the Foley catheter was used as compared to controls, respectively. No such changes were demonstrated in the PGE2 group as compared to the controls. No significant differences were found between the PGE2 group and Foley catheter group as compared to the controls in rates of placental abruption, IPFD, uterine rupture, fetal distress, birth canal lacerations, vacuum deliveries and Apgar scores.

CONCLUSIONS

PGE2 was found to be superior to the Foley catheter for ripening of the uterine cervix in a post-Cesarean parturient, as demonstrated by a lower repeated Cesarean delivery rate.

Cervical ripening and induction of labor with misoprostol, dinoprostone gel, and a Foley catheter: a randomized trial of 3 techniques

OBJECTIVE

The purpose of this study was to compare the efficacy of 3 different techniques of cervical ripening and induction.

STUDY DESIGN

Patients who required cervical ripening and induction were randomized to one of 3 groups: (1) supracervical Foley catheter and intravaginal dinoprostone gel, (2) supracervical Foley catheter and 100 microg oral doses of misoprostol, or (3) serial 100-microg oral doses of misoprostol. Intravenous oxytocin was administered when a protraction disorder of labor was identified.

RESULTS

There were 339 women randomized. There was no significant difference in the time from first intervention to delivery in the 3 groups (P =.546). In each group, a similar percentage of women required oxytocin (P =.103). The rates of cesarean delivery were equivalent among the groups (P =.722). Rates of tachysystole were high but statistically equivalent among the 3 groups. There were no significant differences in Apgar scores or umbilical artery pH.

CONCLUSION

Oral 100 microg serial doses of misoprostol, with or without the use of a supracervical Foley catheter, were equivalent to the use of a supracervical Foley catheter and serial 4-mg doses of dinoprostone gel for cervical ripening and the induction of labor.

Oral versus vaginal misoprostol for labor induction

OBJECTIVE

To compare the safety and effectiveness of vaginal with oral misoprostol for induction of labor.

METHODS

A total of 107 women with clinical indication for induction were randomly assigned to receive oral or vaginal misoprostol. Doses of 100 microg of oral or 25 microg of vaginal misoprostol were given every 3-4 hours. If cervical ripening or active labor did not occur, repeated doses of oral (100-200 microg) or vaginal (25-50 microg) were given until labor was established.

RESULTS

Fifty-nine women received oral misoprostol, and 48 received vaginal administration. Delivery time was similar for the vaginal and oral arms (1074 +/- 488 minutes versus 930 +/- 454 minutes, P =.11). Parity was significantly different (P =.04) for the vaginal and oral groups. The cesarean delivery rate was similar for the vaginal and oral arms (17% versus 15%, P =.72). The number of medication administrations was consistent between groups. Birth weight was not different for patients in the control and treatment groups (vaginal 3281 +/- 507 g versus oral 3359 +/- 541 g, P =.44). Chorioamnionitis and tachysystole were comparable for the oral and vaginal groups. There was no statistical difference in neonatal outcomes. Similar proportions of infants were admitted to the well baby nursery and intermediate care nursery.

CONCLUSION

These findings indicate that, in a closely supervised hospital setting with adequate monitoring, oral misoprostol has the potential to induce labor as safely and effectively as its vaginal analogue.

Factors affecting the likelihood of successful induction after intravaginal misoprostol application for cervical ripening and labor induction

OBJECTIVE

Our purpose was to determine whether maternal age, height and weight, parity, duration of pregnancy, cervical dilatation or Bishop score, and birth weight could be used to predict the likelihood of successful induction in women given intravaginal misoprostol.

STUDY DESIGN

A computerized database was compiled of 1373 pregnancies in which intravaginal misoprostol was given for cervical ripening and labor induction. Most of these women were placed on investigational protocols in which the dose of misoprostol administered was 25 to 50 microg and the dosing intervals ranged from 3 to 6 hours. No more than 24 hours of administration was permitted. Induction was undertaken in women with unfavorable cervical examinations (Bishop scores of 4 or less) and without spontaneous labor or ruptured membranes. Univariate and stepwise multiple regression analyses were performed to identify those factors associated with successful induction, defined as vaginal delivery within 24 hours of induction.

RESULTS

Six hundred fifty-seven (48%) had successful induction. Parity (odds ratio [OR] 2.5, 95% CI 2.0-2.9, P <.0001), initial cervical dilatation (OR 1.9, 95% CI 1.6-2.3, P <.0001), Bishop score (OR 1.6, 95% CI 1.3, 1.8, P <.0001), and gestational age at entry (OR 1.3, 95% CI 1.1-1.5, P =.002) were significant at the.05 level for predicting successful induction. A multivariate stepwise logistic regression was then performed to evaluate each of these as independent predictors. Parity (OR 2.4, 95% CI 2.0-3.0, P <.0001), initial cervical dilatation (OR 1.7, 95% CI 1.4-2.1, P <.0001), and estimated gestational age (OR 1.3, 95% CI 1.1-1.6, P =.003) are significant independent predictors for successful induction, but initial Bishop score is not significant (P =.19) after adjustment for other significant predicting factors.

CONCLUSIONS

The clinical characteristics of parity, initial cervical dilatation, and gestational age at entry are predictors of the likelihood of success of cervical ripening and labor induction with intravaginal misoprostol administration.

The effect of tablet moistening on labor induction with intravaginal misoprostol: a randomized trial

OBJECTIVE

To estimate whether a dosage of 50 microg of misoprostol tablets moistened with 3% acetic acid and administered intravaginally is more efficacious for labor induction than a similar dosage regimen using dry tablets.

METHODS

A total of 177 women who presented with an indication for cervical ripening and labor induction were randomly assigned to one of two treatment groups: 1) intravaginal misoprostol in dry tablet form, or 2) intravaginal misoprostol moistened with 1 mL of 3% acetic acid solution. The primary outcome assessed was the interval from start of induction to vaginal delivery. To detect at least a 3.5-hour difference in the primary outcome with 80% power, 87 subjects were required in each group.

RESULTS

Among 162 patients evaluated, 80 were allocated to the misoprostol dry group and 82 to the misoprostol moistened group. No significant difference was noted for the mean +/- standard deviation interval to vaginal delivery: 1130 +/- 636 minutes for the group who received dry tablets and 1004 +/- 636 minutes for those who received moistened misoprostol tablets (P =.25). Additionally, no statistically significant differences were noted between the groups with respect to need for oxytocin, proportion of patients delivered after a single dose, intrapartum complications (including tachysystole and uterine hyperstimulation), mode of delivery, or perinatal outcomes.

CONCLUSION

Tablet moistening with 3% acetic acid solution does not seem to improve the efficacy of intravaginally administered misoprostol for labor induction.

Nitric oxide induced cervical ripening in the human: Involvement of cyclic guanosine monophosphate, prostaglandin F(2 alpha), and prostaglandin E(2)

OBJECTIVE

The purpose of the study was to investigate possible mechanisms and morphologic changes involved in nitric oxide-induced cervical ripening.

STUDY DESIGN

Women scheduled for surgical termination of first trimester pregnancy were randomized to 1 of 3 groups: isosorbide 5-mononitrate 40 mg 4 hours or 10 hours before the operation or no preoperative treatment. Cervical specimens were obtained for the analysis of tissue levels of cyclic guanosine monophosphate, cyclic adenosine monophosphate, cyclo-oxygenase 1, cyclo-oxygenase 2, prostaglandin F(2 alpha), and prostaglandin E(2) or were fixed in glutaraldehyde for microscopy.

RESULTS

Increased levels of cyclic guanosine monophosphate, cyclo-oxygenase 2, prostaglandin F(2 alpha), and prostaglandin E(2) were found in samples that were exposed to isosorbide 5-mononitrate compared with control samples. Electron microscopy revealed stromal edema and collagen disorganization after isosorbide 5-mononitrate treatment.

CONCLUSION

Cyclic guanosine monophosphate, prostaglandin F(2 alpha), and prostaglandin E(2) are involved in nitric oxide-induced cervical ripening. Nitric oxide causes morphologic changes similar to those changes seen during spontaneous cervical ripening.

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 > or =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.

Prostaglandin E2 gel versus misoprostol for cervical ripening in patients with premature rupture of membranes after 34 weeks

OBJECTIVE

To compare intravaginal misoprostol to prostaglandin (PG) E2 for cervical ripening in women with premature rupture of the membranes (PROM) after 34 weeks of gestation.

METHODS

Women with PROM after 34 weeks of gestation and an unripe cervix were randomized to receive PGE2 (2.5 mg) or misoprostol (50 microg). Both agents were placed intravaginally immediately after randomization, and the dose was repeated 6 hours later if necessary. After another 6 hours from the second insertion, oxytocin treatment was started if labor had not begun. Forty patients in each group were required to show a 30% improvement in delivery within 12 hours in the misoprostol group.

RESULTS

One hundred nine patients were randomized; 54 were assigned to misoprostol and 55 to PGE2. Important demographic and clinical characteristics were similar between the groups. The mean time from first insertion to delivery was 16.4 hours in the misoprostol group and 22.0 hours in the PGE2 group. A second dose was required less frequently in the misoprostol group (22% vs 62% in the PGE2 group), and the percentage of patients delivered within 12 hours was higher in the misoprostol group (41% vs 16%). Tachysystole occurred in 20% and 6% of women in the misoprostol and PGE2 groups, respectively. Hyperstimulation occurred in 9% and 0%, and cesarean delivery in 19% and 26% of women in the misoprostol and PGE2 groups, respectively. Neonatal outcome was similar between groups.

CONCLUSION

Intravaginal misoprostol is more effective than local PGE2 application to treat PROM after 34 weeks of gestation, but tachysystole occurs more commonly with misoprostol.

Misoprostol for women's health: a review

OBJECTIVE

To review published literature on misoprostol for women's health indications to provide a synthesis of available information and highlight areas in need of additional research.

DATA SOURCES

Studies were identified through searches of medical literature databases including MEDLINE, Cochrane Database, and Popline, in addition to a review of references from identified articles.

STUDY SELECTION

We included all studies reported in English and published before March 31, 2001, which evaluated the efficacy of misoprostol alone for labor and delivery, evacuation of the uterus after pregnancy failure and induced abortion. Studies were not excluded based on quality or sample size.

TABULATION, INTEGRATION, AND RESULTS

Misoprostol shows promise for all of the women's health indications addressed. Currently available data, though, are often hard to interpret because of variations in regimen, dose, and outcome measures. The low cost, ease of administration and storage, and widespread availability of misoprostol make it particularly appealing for developing countries. Because many of the women's health problems for which misoprostol could be prescribed currently cause significant mortality and morbidity, increased access to and information on use of misoprostol could help improve women's health especially where these problems are most severe.

CONCLUSION

Further research is needed to identify optimal regimens for misoprostol for obstetric and gynecologic health indications. Registering misoprostol with national drug regulatory authorities for any of several women's health indications could help increase access to and safe use of this drug. Provider training would be a logical subsequent step.

Active pushing versus passive fetal descent in the second stage of labor: a randomized controlled trial

OBJECTIVE

To compare perinatal outcomes among women with epidural anesthesia who were encouraged to push at complete dilatation with those who had a period of rest before pushing began.

METHODS

After a power analysis to determine appropriate sample size (based upon an alpha error rate of.05% and 80% power), a prospective randomized trial of 252 women with epidural anesthesia was conducted. Patients were randomized to a rest period or immediate pushing at complete dilatation. Variables measured included rate of fetal descent, length of time of pushing, the number and type of fetal heart rate decelerations, Apgar scores, arterial cord pH values, perineal injuries, type of delivery, length of second stage, maternal fatigue, and endometritis.

RESULTS

When a period of rest was used before pushing, we found a longer second stage, decreased pushing time, fewer decelerations, and, in primiparous women, less fatigue compared with control patients. Apgar scores, arterial cord pH values, rates of perineal injury, instrument delivery, and endometritis were similar in both groups.

CONCLUSION

Delayed pushing was not associated with demonstrable adverse outcome, despite second-stage length of up to 4.9 hours. In select patients, such delay may be of benefit.

Review on prostaglandin and oxytocin activity in preterm labor

The principal difference between term and preterm labor is how they are activated. It has been proposed that term labor results from physiological activation of the common terminal pathway, whereas preterm labor is a pathological condition caused by multiple etiologies that activate one or more of the components of this pathway. Increased uterine contractility at preterm labor results from activation and stimulation of the myometrium. Myometrium is stimulated by increased concentrations ofprostaglandins and oxytocin. Increased production of stimulatory prostaglandins by intrauterine tissues is generally considered a central component of the cascade of events leading to preterm parturition. Prostaglandins act to mediate cervical ripening and to stimulate uterine contractions and indirectly to increase fundally dominant myometrial contractility by up regulation of gap junctions, oxytocin and arginine vasopressin receptors and synchronizations of contractions. The authors tried to explain the role and influence of oxytocin in human parturition, as well as the novel therapy in inhibiting the contractions in preterm labor. The selective oxytocin inhibitor was tested in vitro on human myometrium and decidua by the author of this article among the first in the world.

Transcervical Foley catheter for preinduction cervical ripening in an outpatient versus inpatient setting

OBJECTIVE

To compare use of the Foley catheter for preinduction cervical ripening in an inpatient versus outpatient setting.

METHODS

A randomized trial was conducted from May 1998 to December 1999. Women with a term gestation in the vertex presentation, a reactive nonstress test, an amniotic fluid index above the fifth percentile, and a Bishop score of no more than 5 were included. The primary outcome variable was a change in Bishop score. A Foley catheter with a 30-mL balloon was placed through the cervix on gentle traction in each group. The outpatient group was then discharged home with written instructions and returned in the morning for induction. The inpatient group was admitted to labor and delivery, with induction started upon extrusion of the Foley.

RESULTS

Sixty-one women were randomized into the outpatient group, and 50 women into the inpatient group. Maternal age, gravidity, previous cesarean delivery, and gestational age did not differ between the groups. The median Bishop score at entry was 3.0 for each group (P =.97). The mean change in Bishop scores after catheter placement was not different between the inpatient and outpatient groups (3.0 versus 3.0; P =.74). The maximum dose of oxytocin, time of oxytocin, epidural rate, induction time, 1-minute and 5-minute Apgar scores, and cord pH were not significantly different. The outpatient group on average avoided 9.6 hours of hospitalization. There were no adverse events or maternal morbidity in either group.

CONCLUSIONS

The Foley bulb is as effective in the outpatient as the inpatient setting for preinduction cervical ripening.