Cervical ripening and labor induction after previous cesarean delivery

Prevalence of uterine rupture among women with one prior low transverse cesarean and women with unscarred uterus undergoing labor induction with PGE2: A systematic review and meta-analysis

BACKGROUND

As uterine rupture may affect as many as 11/1000 women with 1 prior cesarean birth and 5/10.000 women with unscarred uterus undergoing labor induction, we intended to estimate the prevalence of such rare outcome when PGE2 is used for cervical ripening and labor induction.

METHODS

We searched MEDLINE, ClinicalTrials.gov and the Cochrane library up to September 1st 2020. Retrospective and prospective cohort studies, as well as randomized controlled trials (RCTs) on singleton viable pregnancies receiving PGE2 for cervical ripening and labor induction were reviewed. Prevalence of uterine rupture was meta-analyzed with Freeman-Tukey double arcsine transformation among women with 1 prior low transverse cesarean section and women with unscarred uterus.

RESULTS

We reviewed 956 full text articles to include 69 studies. The pooled prevalence rate of uterine rupture is estimated to range between 2 and 9 out of 1000 women with 1 prior low transverse cesarean (5/1000; 95%CI 2-9/1000, 122/9000). The prevalence of uterine rupture among women with unscarred uterus is extremely low, reaching at most 0.7/100.000 (<1/100.000.000; 95%CI <1/100.000.000-0.7/100.000, 8/17.684).

CONCLUSIONS

Uterine rupture is a rare event during cervical ripening and labor induction with PGE2.

No. 155-Guidelines for Vaginal Birth After Previous Caesarean Birth

OBJECTIVE

To provide evidence-based guidelines for the provision of a trial of labour (TOL) after Caesarean section.

OUTCOME

Fetal and maternal morbidity and mortality associated with vaginal birth after Caesarean (VBAC) and repeat Caesarean section.

EVIDENCE

MEDLINE database was searched for articles published from January 1, 1995, to February 28, 2004, using the key words "vaginal birth after Caesarean (Cesarean) section." The quality of evidence is described using the Evaluation of Evidence criteria outlined in the Report of the Canadian Task Force on the Periodic Health Exam.

RECOMMENDATIONS

VALIDATION: These guidelines were approved by the Clinical Practice Obstetrics and Executive Committees of the Society of Obstetricians and Gynaecologists of Canada.

The misoprostol vaginal insert compared with oral misoprostol for labor induction in term pregnancies: a pair-matched case-control study

AIM

To compare the efficacy and safety of the misoprostol vaginal insert (MVI) with an off-label use of oral misoprostol (OM).

METHODS

Pair-matched case-control study comparing the induction of labor with a retrievable MVI to OM. The primary outcomes were the time from induction to delivery and the cesarean section rate. Secondary outcomes included uterine tachysystole, tocolysis, fetal scalp blood testing, meconium-stained amniotic fluid, umbilical arterial pH, and Apgar score.

RESULTS

One hundred and thirty eight women ≥37/0 weeks pregnant undergoing labor induction with misoprostol were included. The mean time from application to delivery was significantly shorter and the caesarean section rate significantly higher in the MVI group (P<0.01) with an odds ratio of 2.75 (95% CI: 1.21-6.25) in favor of vaginal delivery in the OM group. The mean 5-min Apgar scores and arterial cord pH values were significantly lower in the MVI group. An arterial pH value of 7.10-7.19 was found in 26.1% and 15.9%, and a value <7.10 was found in 4.3% and 0% of MVI and OM cases, respectively.

CONCLUSION

The MVI compared with OM significantly shortened the time from application to delivery at the expense of a higher cesarean section rate and negative effects on neonatal outcomes.

Induction of labor in patients with an unfavorable cervix after a cesarean using an osmotic dilator versus vaginal prostaglandin

BACKGROUND

Trial of labor after cesarean (TOLAC) is a viable option for safe delivery. In some cases cervical ripening and subsequent labor induction is necessary. However, the commonly used prostaglandins are not licensed in this subgroup of patients and are associated with an increased risk of uterine rupture.

METHODS

This cohort study compares maternal and neonatal outcomes of TOLAC in women (n=82) requiring cervical ripening agents (osmotic dilator vs. prostaglandins). The initial Bishop scores (BSs) were 2 (0-5) and 3 (0-5) (osmotic dilator and prostaglandin group, respectively). In this retrospective analysis, Fisher's exact test, the Kruskal-Wallis rank sum test and Pearson's chi-squared test were utilized.

RESULTS

Vaginal birth rate (including operative delivery) was 55% (18/33) in the osmotic dilator group vs. 51% (25/49) in the dinoprostone group (P 0.886). Between 97% and 92% (32/33 and 45/49) (100%, 100%) of neonates had an Apgar score of >8 after 1 min (5, 10 min, respectively). The time between administration of the agent and onset of labor was 36 and 17.1 h (mean, Dilapan-S® group, dinoprostone group, respectively). Time from onset of labor to delivery was similar in both groups with 4.4 and 4.9 h (mean, Dilapan-S® group, dinoprostone group, respectively). Patients receiving cervical ripening with Dilapan-S® required oxytocin in 97% (32/33) of cases. Some patients presented with spontaneous onset of labor, mostly in the dinoprostone group (24/49, 49%). Amniotomy was performed in 64% and 49% (21/33 and 24/49) of cases (Dilapan-S® group and dinoprostone group, respectively).

CONCLUSIONS

This pilot study examines the application of an osmotic dilator for cervical ripening to promote vaginal delivery in women who previously delivered via cesarean section. In our experience, the osmotic dilator gives obstetricians a chance to perform induction of labor in these women.

Back to "once a caesarean: always a caesarean"? A trend analysis in Switzerland

PURPOSE

Caesarean sections (CS) have significantly increased worldwide and a previous CS is nowadays an important and increasingly reported indication to perform a repeat CS. There is a paucity of information in Switzerland on the incidence of repeat CS after previous CS and relationship between the rates of vaginal birth after CS (VBAC). The aim of this study was to analyse the actual trend in VBAC in Switzerland.

METHODS

We performed a retrospective cohort study to analyse the proportion of VBAC among all pregnant women with previous sections which give birth during two time periods (group 1:1998/1999 vs. group 2:2004/2005) in our tertiary care referral hospital and in the annual statistics of Swiss Women's Hospitals (ASF-Statistics). In addition, the proportion of induction of labour after a previous caesarean and its success was analysed.

RESULTS

In both cohorts studied, we found a significant decrease of vaginal births (p < 0.05) and a significant increase of primary elective repeat caesarean section (p < 0.05) from the first to the second time period, while there was a decrease of secondary repeat caesarean sections. The prevalence of labour induction did not decrease.

CONCLUSION

Our study shows that vaginal birth after a prior caesarean section has decreased over time in Switzerland. There was no significant change in labour induction during the study period. While this trend might reflect an increasing demand for safety in pregnancy and childbirth, it concomitantly increases maternal risks of further pregnancies, and women need to be appropriately informed about long-term risks.

Misoprostol for Labour Induction after Previous Caesarean Section - Forever a "No Go"?

Misoprostol in oral or vaginal form is an established method of labour induction worldwide. Its use after previous caesarean section is associated with a high rate of uterine rupture; according to international guidelines it is therefore contraindicated in this setting. However the evidence base for this recommendation comprises case reports, one randomised trial that was discontinued prematurely, and numerous low quality retrospective data analyses published between 1997 and 2004. New insights into e.g. resorption kinetics, dosage and application intervals, dose dependant uterine hyperstimulation rates, as well as increasing clinical experience with misoprostol have lead to a critical reappraisal of these "historical" studies. Accordingly the evidence supporting a ban on vaginal and particularly oral misoprostol for labour induction in the context of a scarred uterus is currently insufficient for a convincing guideline recommendation. In view of the clear advantages of misoprostol over prostaglandin E₂ (cheaper, more effective) a retrospective review of registry data should be conducted to determine the incidence of uterine rupture following misoprostol and the circumstances in which it occurs. A prospective, randomised trial could then be conducted on the basis of these findings (e.g. oral misoprostol vs. vaginal prostaglandin E₂); known risk factors for uterine rupture including the type of uterine scar would need to be taken into account when selecting patients for vaginal delivery. Until new data from well-designed studies are available, misoprostol will continue to be contraindicated in clinical guidelines for use in labour induction after previous caesarean section.

Double-balloon catheter and sequential vaginal prostaglandin E2 versus vaginal prostaglandin E2 alone for induction of labor after previous cesarean section

PURPOSE

To evaluate the efficacy of inducing labor using a double-balloon catheter and vaginal prostaglandin E2 (PGE2) sequentially, in comparison with vaginal PGE2 alone after previous cesarean section.

METHODS

A total of 264 pregnant women with previous cesarean section undergoing labor induction at term were included in this prospective multicentre cohort study. Induction of labor was performed either by vaginal PGE2 gel or double-balloon catheter followed by vaginal PGE2. The primary outcome measure was the cesarean section rate.

RESULTS

The cesarean section rate was 37 % without any statistically significant difference between the two groups (PGE2: n = 41, 37 % vs. balloon catheter/PGE2: n = 41, 42 %; P = 0.438). The median (range) number of applications of PGE2 [2 (1-10) versus 1 (0-8), P < 0.001] and the total amount of PGE2 used in median (range) mg [2 (1-15) vs. 1 (0-14), P = 0.001] was less in the balloon catheter/PGE2 group. Factors significantly increasing risk for cesarean section were "no previous vaginal delivery" (OR 5.391; CI 2.671-10.882) and "no oxytocin augmentation during childbirth" (OR 2.119; CI 1.215-3.695).

CONCLUSIONS

The sequential application of double-balloon catheter and vaginal PGE2 is as effective as the sole use of vaginal PGE2 with less applications and total amount of PGE2.

Efficacy and safety of labour induction in patients with a single previous caesarean section: a proposal for a clinical protocol

PURPOSE

To evaluate the efficacy and safety of induction in women with a single prior Caesarean section.

METHODS

This was a cohort study in which we included all singleton pregnancies in patients with a single prior Caesarean who delivered between 2007 and 2012. Methods of induction were ocytocic infusion plus amniotomy (if Bishop score ≥6) or insertion of a Foley catheter (Bishop <6).

RESULTS

Of the 2,075 patients included, 806 (38.8 %) had an elective repeat Caesarean, 1,045 (50.4 %) went into spontaneous labour, 89 (4.3 %) were induced by artificial rupture of the membranes and infusion of ocytocics and 135 (6.5 %) were induced using a Foley catheter. Rates of vaginal delivery were 79.2, 79.8 and 43.7 %, respectively. Six cases of uterine rupture were reported in the group of patients who went into spontaneous labour. There was no difference between groups with regard to neonatal morbidity. On multivariate analysis, risk factors for Caesarean delivery were macrosomia (OR 2.04, 95 % CI 1.31-3.18) and induction by Foley catheter (OR 3.73, 95 % CI 2.47-5.62); protective factors were previous vaginal delivery (OR 0.41, 95 % CI 0.29-0.57) and cervical dilatation (OR 0.84, 95 % CI 0.78-0.91).

CONCLUSIONS

Uterine induction after a single Caesarean section with ocytocic infusion and amniotomy where the cervix is favourable does not appear to entail any significant added risk in terms of maternal or foetal morbidity. Foley catheter induction is a reasonable option if the cervix is not ripe.

Induction of labor in women that had a previous cesarean delivery

OBJECTIVE

This study aims to evaluate factors that predict the likelihood of the success of induction of labor (IOL) in women that had a previous cesarean section (pCS).

METHODS

Pregnant women with one pCS performed more than 18 months prior were included in this retrospective observational study. Of the 242 eligible women, 234 were enrolled; 120 (51.3%) of these women delivered vaginally (VD), with the remainder receiving a repeat CS.

RESULTS

The main reasons for IOL were premature rupture of membranes (PROM) (37.1%) and post-date pregnancy (26.5%). Babies with a birth weight≥4000 g were more prevalent in women undergoing CS (21/114; 18.4%, p<0.02) and were associated with the failure of IOL. Uterine rupture during labor (1.3%) occurred in three cases. Having had a previous vaginal delivery (VD) (p=0.01), not being African (p=0.022), and receiving IOL for PROM (p=0.04) with a cervical Bishop score≥5 (p=0.015) significantly predicted the occurrence of a VD, with an 15% variance (p<0.001). An age>35 years appears to not affect the success of induction.

CONCLUSIONS

A successful IOL should be expected in Caucasian women induced for PROM with a favorable Bishop score.

An audit about labour induction, using prostaglandin, in women with a scarred uterus

OBJECTIVES

Induction of labour after a previous caesarean section is still controversial. We aim to analyse, in a population of women who have a uterine scar, the maternal, foetal and neonatal complications in relation to the mode of labour and delivery.

STUDY DESIGN

Retrospective analysis of collected data from all the singleton deliveries of patients with a scarred uterus (N=798), admitted to the hospital between August 2006 and March 2009.

OUTCOMES

maternal and perinatal complications.

RESULTS

Among 798 singleton deliveries, 36.1% had a spontaneous labour, 12.6% a prostaglandin-induced labour and 2.9% an ocytocin-induced labour, and 48.4% had an elective caesarean section. The chance of delivering vaginally was respectively 84.4% for those who had a spontaneous labour, 75.2% for those who were induced using prostaglandin, 82.6% after induction using ocytocin. There were eight uterine ruptures, four after spontaneous labour (1.4%), two after prostaglandin induction (2%) and two at the time of an iterative caesarean section (0.5%). There were no differences between groups, except the risk of haemorrhage (17.4% after spontaneously induced labour, 34.8% after ocytocin, 17.8% after prostaglandin and 44.6% after iterative caesarean section; p<0.005) and the neonatal admissions when analysed by intention to treat only (8.3% after spontaneously induced labour, 9.1% after ocytocin, 12% after prostaglandin and 16.8% after iterative caesarean section; p<0.009).

CONCLUSION

Although no increase in maternal or perinatal outcome was observed in relation to prostaglandin-induced labour after caesarean section, this study is too underpowered to exclude an increased risk.

[National Survey of the management and delivery of the unicicatriciel uterus in France in 2009]

OBJECTIVES

To audit French maternity units' obstetric procedures in delivering women who have undergone previous caesarean section.

MATERIAL AND METHODS

[corrected] Survey by questionnaire collecting the obstetrical practices about agreement and methods of delivery of women with previous caesarean section in France in 2009. The questionnaire was sent by email to 472 private and public maternity units of grades 1, 2 and 3.

RESULTS

One hundred and seventy-five units (37%) replied, about 305,710 new-borns representated, few private maternity units answered (12.6% of the answers), despite their accounting for 30.2% of obstetric work; 50.9% had no written policy for the management of patients with previous caesarean; 53.1% of units relied on written consent from women attempting vaginal delivery after previous caesarean. The documentation concerning previous caesarean section was considered important by 73.1% of units. Rates for acceptance of attempted vaginal delivery were as follows: after a transverse lower uterine segment incision - 100% of maternity units; after a transverse corporeal incision - 30.3% of units and after a vertical incision - 25.1% of units; 55.4% of maternities induced labour after a previous caesarean section, 29.9% of them with prostaglandin E2; 64% used internal tocometry. Radiopelvimetry was a routine examination for 55.9% of grade 1 units, compared with 13.5% of grade 3 (P=0.000035). Induction was practised by more grade 3 units (78.3%) than grade 1 units (44%) (P=0.009). No team acknowledged carrying out subsequent caesarean delivery as a matter of principle.

CONCLUSIONS

This national survey, statistically representative in terms of the numbers of deliveries, gives an objective view of different practices, according to type and grade of maternity unit in France, in 2009. The data indicate that it is desirable to devise specific recommendations in order to harmonise management, bearing in mind the frequency of caesarean sections.

Inconsistent evidence: analysis of six national guidelines for vaginal birth after cesarean section

BACKGROUND

Guidelines are increasingly used to direct clinical practice, with the expectation that they improve clinical outcomes and minimize health care expenditure. Several national guidelines for vaginal birth after cesarean section (VBAC) have been released or updated recently, and their range has created dilemmas for clinicians and women. The purpose of this study was to summarize the recommendations of existing guidelines and assess their quality using a standardized and validated instrument to determine which guidelines, if any, are best able to guide clinical practice.

METHODS

English language guidelines on VBAC were purposively selected from national and professional organizations in the United Kingdom, United States, Canada, New Zealand, and Australia. The Appraisal of Guidelines for Research and Evaluation (AGREE) instrument was applied to each guideline, and each was analyzed to determine the range and level of evidence on which it was based and the recommendations made.

RESULTS

Six guidelines published or updated between 2004 and 2007 were examined. Only two of the six guidelines scored well overall using the AGREE instrument, and the evidence used demonstrated great variety. Most guidelines cited expert opinion and consensus as evidence for some recommendations. Reported success rates for VBAC ranged from 30 to 85 percent, and reported rates of uterine rupture ranged from 0 to 2.8 percent.

CONCLUSIONS

VBAC guidelines are characterized by quasi-experimental evidence and consensus-based recommendations, which lead to wide variability in recommendations and undermine their usefulness in clinical practice.

Obstetric management and outcome of pregnancy in women with a history of caesarean section in the Netherlands

OBJECTIVE

To determine mode of delivery and occurrence of uterine rupture in women with a previous caesarean section (CS) in the Netherlands.

MATERIALS AND METHODS

During a 1-year period 38 hospitals in the Netherlands registered prospectively mode of delivery, use of prostaglandins or oxytocin and occurrence of uterine rupture in all women with a previous CS.

RESULTS

There were 4569 women with a previous CS. Trial of labour (TOL) was attempted in 71.7%, of whom 76.0% delivered vaginally. The vaginal birth after caesarean (VBAC)-rate was 54.4%. Forty-nine uterine ruptures occurred (1.1%), of which 48 occurred during a TOL (1.5%). There were four perinatal deaths (1.2/1000 TOL) and 3 hysterectomies (0.9/1000 TOL) related to the rupture. Use of prostaglandin E2 alone or combined with oxytocin was significantly associated with an increased risk of uterine rupture (OR 6.8, 95% CI 3.2-14.3, OR 4.8, 95% CI 1.6-14.6, respectively). The same held for augmentation with oxytocin (OR 2.2, 95% CI 1.04-5.0).

CONCLUSION

The success rate of TOL was 76%, resulting in a VBAC rate of 54%. Uterine rupture occurred in 1.5% during a TOL, with a risk of perinatal death of 1.2 per 1000. The risk of uterine rupture increased significantly when labour was induced with prostaglandins alone or combined with oxytocin or when labour was augmented with oxytocin.

Vaginal Misoprostol Administration for Cervical Ripening and Labor Induction

Intravaginal misoprostol has been shown to be an effective agent for cervical ripening and induction of labor. Vaginal application of misoprostol has been reported in over 9000 women worldwide and seems to have safety profile similar to that of endocervically and intravaginally administered dinoprostone. Concern arises with the use of higher doses of intravaginal misoprostol (50 mcg or more) and the association with uterine contractile abnormalities and for this reason, use of low-dose misoprostol regimen has been recommended by the American College of Obstetricians and Gynecologists. The recommendation is use of a 25-mcg dose of misoprostol inserted into the posterior vaginal fornix and repeated every 3 to 6 hours as needed. Misoprostol administration to women with prior cesarean births seems to increase the likelihood of uterine scar disruption and should not be used in these women. There are reports of uterine rupture in women with unscarred uteri treated with vaginally applied misoprostol. Therefore, all patients need to be monitored adequately after misoprostol administration. Although there is a growing body of data regarding the ambulatory use of intravaginal misoprostol for cervical ripening, its use for this purpose cannot be recommended outside of investigational protocols at this time because of concerns for maternal and neonatal safety.

Prior Cesarean: A Contraindication to Labor Induction?

In 2004, cesarean rates were the highest ever in the United States. Simultaneously, the vaginal birth after cesarean (VBAC) rate fell, largely a result of reports of uterine rupture associated with VBAC attempts. This chapter reviews the efficacy and safety of VBAC associated with labor induction. Mechanical and pharmacologic methods of labor induction (notably misoprostol) are associated with increased maternal and perinatal morbidity compared with spontaneous VBAC attempts. However, the absolute risks remain low. Labor induction is not contraindicated in women with a prior cesarean but sound judgment, clinical precautions and specific consent are required.

Guidelines for Vaginal Birth After Previous Caesarean Birth

OBJECTIVE

To provide evidence-based guidelines for the provision of a trial of labour (TOL) after Caesarean section.

OUTCOME

Fetal and maternal morbidity and mortality associated with vaginal birth after Caesarean (VBAC) and repeat Caesarean section.

EVIDENCE

MEDLINE database was searched for articles published from January 1, 1995, to February 28, 2004, using the key words "vaginal birth after Caesarean (Cesarean) section". The quality of evidence is described using the Evaluation of Evidence criteria outlined in the Report of the Canadian Task Force on the Periodic Health Exam.

RECOMMENDATIONS

1. Provided there are no contraindications, a woman with 1 previous transverse low-segment Caesarean section should be offered a trial of labour (TOL) with appropriate discussion of perinatal risks and benefits. The process of informed consent with appropriate documentation should be an important part of the birth plan in a woman with a previous Caesarean section (II-2B). 2. The intention of a woman undergoing a TOL after Caesarean section should be clearly stated, and documentation of the previous uterine scar should be clearly marked on the prenatal record (II-2B). 3. For a safe labour after Caesarean section, a woman should deliver in a hospital where a timely Caesarean section is possible. The woman and her health care provider must be aware of the hospital resources and the availability of obstetric, anesthetic, pediatric, and operating-room staff (II-2A). 4. Each hospital should have a written policy in place regarding the notification and (or) consultation for the physicians responsible for a possible timely Caesarean section (III-B). 5. In the case of a TOL after Caesarean, an approximate time frame of 30 minutes should be considered adequate in the set-up of an urgent laparotomy (III-C). 6. Continuous electronic monitoring of women attempting a TOL after Caesarean section is recommended (II-2A). 7. Suspected uterine rupture requires urgent attention and expedited laparotomy to attempt to decrease maternal and perinatal morbidity and mortality (II-2A). 8. Oxytocin augmentation is not contraindicated in women undergoing a TOL after Caesarean section (11-2A). 9. Medical induction of labour with oxytocin may be associated with an increased risk of uterine rupture and should be used carefully after appropriate counselling (II-2B). 10. Medical induction of labour with prostaglandin E2 (dinoprostone) is associated with an increased risk of uterine rupture and should not be used except in rare circumstances and after appropriate counselling (II-2B). 11. Prostaglandin E1 (misoprostol) is associated with a high risk of uterine rupture and should not be used as part of a TOL after Caesarean section (II-2A). 12. A foley catheter may be safely used to ripen the cervix in a woman planning a TOL after Caesarean section (II-2A). 13. The available data suggest that a trial of labour in women with more than 1 previous Caesarean section is likely to be successful but is associated with a higher risk of uterine rupture (II-2B). 14. Multiple gestation is not a contraindication to TOL after Caesarean section (II-2B). 15. Diabetes mellitus is not a contraindication to TOL after Caesarean section (II-2B). 16. Suspected fetal macrosomia is not a contraindication to TOL after Caesarean section (II-2B). 17. Women delivering within 18 to 24 months of a Caesarean section should be counselled about an increased risk of uterine rupture in labour (II-2B). 18. Postdatism is not a contraindication to TOL after Caesarean section (II-2B). 19. Every effort should be made to obtain the previous Caesarean section operative report to determine the type of uterine incision used. In situations where the scar is unknown, information concerning the circumstances of the delivery is helpful in determining the likelihood of a low transverse incision. If the likelihood of a low transverse incision is high, a TOL after Caesarean section can be offered (II-2B).

VALIDATION

These guidelines were approved by the Clinical Practice Obstetrics and Executive Committees of the Society of Obstetricians and Gynaecologists of Canada.

Risks of induction of labour in women with a uterine scar from previous low transverse caesarean section

OBJECTIVE

Recent studies have shown that among women with uterine scars from previous caesarean section of any type, induction of labour is associated with increased risk of uterine rupture compared with spontaneous labour. We have assessed the risk of uterine rupture in a cohort of women with a previous low transverse caesarean section in whom induction and management of labour were performed according to a strict protocol.

DESIGN

Cohort study.

SETTING

University Hospital.

POPULATION

All women with a singleton pregnancy and a previous low transverse caesarean section requiring induction of labour from 1/1/1992 to 12/30/2001 (n = 310) were compared with a control cohort during the same study period constituted of women with a previous low transverse caesarean section in spontaneous labour (n = 1011).

METHODS

Clinical characteristics and rate of uterine rupture of women with previous caesarean section undergoing induction of labour were compared with those of women with previous caesarean section in spontaneous labour.

MAIN OUTCOME MEASURE

Incidence of uterine rupture.

RESULTS

Uterine rupture occurred in 0.3% in the previous caesarean section--induction group versus 0.3% in the previous caesarean section--spontaneous labour group (P = 0.9). Logistic regression analysis showed no significant difference in the rate of uterine rupture between the induction and spontaneous labour group (P = 0.67) after controlling for maternal age, parity, duration of labour, gestational age at delivery and birthweight.

CONCLUSION

Among women with a previous low transverse caesarean section, induction of labour is not associated with significantly higher rates of uterine rupture compared with spontaneous labour, provided a consistent protocol with strict criteria for intervention is adopted.

Our Experience with Vaginal Prostaglandin-E2 for Induction of Labor in Qatar: Six Months Review

In order to review our experience with prostaglandin-E2 for the induction of labour and to evaluate its safety and outcomesa retrospective study was carried out at the Women's Hospital, Hamad Medical Corporation, over a six-month period. Three hundred and thirty four patients (7% of total deliveries) were induced by PGE2 (Dinoprostone), including 105 (30%) nulliparae and 229 (70%) multiparae. Patients with a history of one previous lower segment caesarean section were also included. Post date pregnancy and diabetes were the most common indications for induction.

There were significant differences in the two groups regarding the number of doses and the mean total dose of PGE2 used. The need for syntocinon augmentation was more in the nulliparae (41% vs 22%). Failed induction occurred only in nulliparae. The rate of caesarean section in induced labour remained significantly low compared with a spontaneous labour (11.6% vs 10.7%). The caesarean section rate was higher in the nulliparae (16.0% vs 9.6%) but this was not statistically significant. The caesarean section rate was higher when Bishop score 0-4 (76% vs 24%). Only two of the babies in the study group had an Apgar score less than 7 at 5 minutes. There was one caesarean hysterectomy because of postpartum hemorrhage associated with the PGE2 induction.

Conclusion: The calculated induction rate with PGE2 was 7% of total deliveries. Induction of labour with PGE2 in a grandmultiparae and previous caesarean section is relatively safe but further multicentre studies are needed to confirm our findings.

A benefit-risk assessment of misoprostol for cervical ripening and labour induction

Misoprostol, a prostaglandin E(1) analogue, is widely used in the US and other countries for cervical ripening and labour induction. Its use for these indications is not approved by the US Food and Drug Administration (FDA). The manufacturer of misoprostol issued a letter to American healthcare providers in August 2000, cautioning against the use of misoprostol in pregnant women and citing a lack of safety data for its use in obstetrical practice. The only FDA-approved indication in the product labelling is the treatment and prevention of intestinal ulcer disease resulting from nonsteroidal anti-inflammatory drug use. Multiple trials have proven that when applied vaginally, misoprostol is an effective agent for cervical ripening and labour induction in term pregnancy. The use of oxytocin augmentation is reduced when intravaginal misoprostol is used compared with other agents. Misoprostol use in obstetrics carries the added benefits of temperature stability at room temperature, which is unlike other prostaglandin preparations which require refrigeration or freezing, and reduced cost. However, debate continues regarding the optimal dose, dosage regimen, and route of administration. Uterine contraction abnormalities are often found in association with higher misoprostol doses (50 microg or more) given vaginally or orally. Some trials also indicate increased frequencies of meconium passage, neonatal acidaemia and caesarean delivery for fetal distress in women receiving higher doses of vaginally applied misoprostol. However, most trials fail to demonstrate a significant change in the caesarean delivery rate with the use of misoprostol, although a recent meta-analysis indicated that the use of intravaginal misoprostol is associated with a lowering of the caesarean rate when compared with pooled controls. Low-dose misoprostol (25 microg) is an effective agent for cervical ripening and labour induction when used in a judicious and cautious fashion. There are insufficient data to support the widespread use of oral misoprostol for cervical ripening and labor induction. Some trials suggest that this approach may be effective; however, the ideal dose and administration regimen have yet to be defined.

Severe obstetric morbidity

Obstetric morbidity is an important marker of the quality of obstetric care. This review explores the definition, incidence and significance of obstetric morbidity. Some topical issues related to obstetric morbidity are discussed. In addition, the importance of long-term morbidity and violence against women is highlighted.

Labor induction

Labor induction has become commonplace in modern obstetrics. The increasing rate of labor induction has probably played a role in the increased rate of cesarean delivery observed in the United States during the past few decades. Clearly, the favorability of the cervix has a substantial impact on the potential success of any labor induction. Induction in the setting of an unfavorable cervix can result in prolonged induction, prolonged hospitalization, failed induction, and an increased cesarean delivery rate. In this modern era of healthcare reform and cost containment, the identification of therapeutic strategies to enhance the success and cost-effectiveness of labor induction are of great interest. Ongoing research is needed to advance our knowledge of the mechanisms of parturition and cervical ripening in order to direct interventions for labor induction more effectively.