Evidence based case report: use of prostaglandins to induce labour in women with a caesarean section scar

Maternal and perinatal outcomes in women with and without hypertensive syndromes submitted to induction of labor with misoprostol

OBJECTIVES

To determine maternal and perinatal outcomes according to the mode of delivery in normotensive and hypertensive women bearing a live, full-term fetus, who were submitted to labor induction with misoprostol.

METHODS

Retrospective cohort study. The endpoints were tachysystole, uterine hyperstimulation, indications for cesarean section, severe maternal morbidity, side effects, maternal death, 1st/5th minute Apgar, neonatal death, requirement for neonatal intensive care, and birth weight (grams). The chi-square or Fisher's exact test was applied at a significance level of 5%. Risk ratios (RRs) and their 95% confidence intervals (95% CI) were calculated.

RESULTS

No significant differences were found in maternal outcome as a function of mode of delivery. First-minute Apgar score <7 was less common with vaginal deliveries in normotensive women (RR = 0.41; 95% CI: 0.18-0.90), this being the only significant difference in perinatal outcome.

CONCLUSION

Maternal and perinatal outcomes were similar in hypertensive and normotensive women submitted to labor induction with misoprostol.

Vaginal prostaglandin gel to induce labour in women with one previous caesarean section

This retrospective study reviewed the mode of delivery when vaginal prostaglandins were used to induce labour in women with a single previous lower segment caesarean section. Over a 4-year period, PGE 2 gel was used cautiously in low doses in 54 women. Induction with PGE 2 gel was associated with an overall vaginal birth after caesarean section (VBAC) rate of 74%, which compared favourably with the 74% VBAC rate in women who went into spontaneous labour (n = 1969). There were no adverse outcomes recorded after the prostaglandin inductions but the number reported are too small to draw any conclusions about the risks, such as uterine rupture. We report our results because they may be helpful in assessing the chances of a successful VBAC in the uncommon clinical circumstances where prostaglandin induction is being considered.

Intracervical prostaglandins for induction of labour

BACKGROUND

Prostaglandins have been used for cervical ripening and induction of labour since the 1970s. The goal of the administration of prostaglandins in the process of induction of labour is to achieve cervical ripening before the onset of contractions. One of the routes of administration that was proposed is intracervical. Using this route, prostaglandins are less easy to administer and the need for exposing the cervix may cause discomfort to the woman.

OBJECTIVES

To determine the effects of intracervical prostaglandins for third trimester cervical ripening or induction of labour compared with placebo/no treatment and with vaginal prostaglandins (except misoprostol).

SEARCH STRATEGY

We searched the Cochrane Pregnancy and Childbirth Group's Trials Register (August 2007) and bibliographies of relevant papers.

SELECTION CRITERIA

Clinical trials comparing intracervical prostaglandins 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 (vaginal prostaglandins, except misoprostol).

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

Fifty-six trials (7738 women) are included. INTRACERVICAL PGE2 WITH PLACEBO/NO TREATMENT: 28 TRIALS, 3764 WOMEN: Four studies reported the number of women who did not achieve vaginal delivery within 24 hours, showing a decreased risk with PGE2 (relative risk (RR) 0.61; 95% confidence interval (CI) 0.47 to 0.79). There was a small, and statistically non-significant, reduction of the risk of caesarean section when PGE2 was used (RR 0.88; 95% CI 0.77 to 1.00). The finding was statistically significant in a subgroup of women with intact membranes and unfavourable cervix only (RR 0.82; 95% CI 0.68 to 0.98). The risk of hyperstimulation with fetal heart rate (FHR) changes was not significantly increased (RR 1.21; 95% CI 0.72 to 2.05). However, the risk of hyperstimulation without FHR changes was significantly increased (RR 1.59; 95% CI 1.09 to 2.33. INTRACERVICAL PGE2 WITH INTRAVAGINAL PGE2: 29 TRIALS, 3881 WOMEN: The risk of not achieving vaginal delivery within 24 hours was increased with intracervical PGE2 (RR 1.26; 95% CI 1.12 to 1.41). There was no change in the risk of caesarean section (RR 1.07; 95% CI 0.93 to 1.22). The risks of hyperstimulation with FHR changes (RR 0.76; 95% CI 0.39 to 1.49) and without FHR changes (RR 0.80; 95% CI 0.56 to 1.15) were non-significantly different with the two methods of PGE2 administration. Only one trial with small sample size reported on women's views, with no difference between groups. INTRACERVICAL PGE2 LOW DOSE WITH INTRACERVICAL PGE2 HIGH DOSE: TWO TRIALS, 102 WOMEN: The trials are too small to provide any useful information.

AUTHORS' CONCLUSIONS

Intracervical prostaglandins are effective compared to placebo, but appear inferior when compared to intravaginal prostaglandins.

Do vaginal birth after cesarean outcomes differ based on hospital setting?

OBJECTIVE

The objective of the study was to test the null hypothesis that outcomes of vaginal birth after cesarean (VBAC) do not differ on the basis of the hospital setting.

STUDY DESIGN

The study was a retrospective cohort study of women who were offered VBAC in 17 hospitals from 1996 to 2000. VBAC attempts occurring in hospitals with and without obstetrics-gynecology residency programs were compared, as were outcomes from university and community hospitals. Bivariate and multivariate logistic regression analyses assessed the association between hospital setting and VBAC outcomes.

RESULTS

Of 25,065 women with 1 or more prior cesareans, the VBAC attempt rate was 56.1% at hospitals with obstetrics-gynecology residencies, 51.3% at hospitals without obstetrics-gynecology residencies, 61% at university hospitals, and 50.4% at community hospitals. The occurrence of failed VBAC, blood transfusion, or composite adverse outcome did not differ by hospital setting. There was a significant increase in the uterine rupture rate at community (1.2%) vs university hospitals (0.6%), but the absolute risk remained low.

CONCLUSION

The rate of VBAC-associated complications is low, independent of hospital setting.

Induction of labour with previous caesarean delivery: where do we stand?

PURPOSE OF REVIEW

This paper reviews the literature to elucidate the international stance on induction of labour in women with previous caesarean section.

RECENT FINDINGS

There is no evidence to suggest that current induction methods are less effective in women with previous caesarean section. It would, therefore, seem logical to use the same regimens as for women with intact uteri, including prostaglandins, particularly in women with unfavourable cervices. The clinical decision making and counselling, however, will always focus on safety, not effectiveness. There is no question that induction of labour is associated with higher risk of uterine rupture, but quantifying this risk remains elusive.

SUMMARY

For the present, we will continue our practice, based on the sources of the best evidence available. Improvements in obstetric care have not only reduced the risks associated with uterine rupture but also risks associated with caesarean section. Therefore, both elective caesarean section and induction of labour, with or without prostaglandins, are reasonable choices for women who need induction with previous caesarean section. The efforts to better quantify the benefits/risks of various policies and regimens should continue, but should be complemented with qualitative studies to obtain crucial insight into the demands and challenges confronting women and clinicians to identify factors influencing their decision-making or their preferences.

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.

Uterine rupture after induction of labour in women with previous caesarean section

BACKGROUND

The issues related to safety of induction of labour in women with previous caesarean section remain controversial. The main adverse outcome fuelling this debate is a "small" risk of uterine rupture that is potentially devastating for both the mother and the fetus.

OBJECTIVE

To estimate the risk of uterine rupture or dehiscence in women who require induction of labour with previous caesarean sections.

DESIGN

Five year retrospective review of computerised hospital records and case note review of index cases.

SETTING

Large inner city teaching hospital.

POPULATION

Two hundred and five women who had their labour induced with history of one lower segment caesarean section.

METHODS

This study was conducted at Liverpool Women's Hospital, a tertiary referral centre, with approximately 6000 births per annum. We searched the hospital's computerised records of deliveries from June 1997 to June 2002 and reviewed all indications and outcomes of induction of labour in women with one previous caesarean section. Women with singleton pregnancy and cephalic presentation were then divided into three groups: those with one previous caesarean section and no previous vaginal deliveries, those whose last delivery was a caesarean section but had delivered vaginally before and those whose last delivery was by vaginal route, but had had one caesarean section in the past.

MAIN OUTCOME MEASURES

Uterine rupture or dehiscence, adverse neonatal outcome.

RESULTS

Two hundred and five women were included. There were four cases of uterine rupture and one dehiscence (2.4%, 95% CI 0.8-5.6%). Two babies were profoundly acidotic at birth, but all five neonates were healthy when discharged from hospital with no long term morbidity. All five cases occurred in the group of women with no previous vaginal deliveries. The intrauterine pressure catheter recordings had contributed to the diagnosis of uterine rupture/dehiscence in three out of five cases.

CONCLUSION

In women with previous caesarean section and no vaginal deliveries, induction of labour carries a relatively high risk of uterine rupture/dehiscence despite all precautions, including intrauterine pressure monitoring.

Maternal intravaginal prostaglandin E2 gel before elective caesarean section at term to induce catecholamine surge in cord blood: randomised, placebo controlled study

OBJECTIVE

To test the hypothesis that the application of intravaginal prostaglandin E(2) gel before elective caesarean section (ECS) will induce a catecholamine surge in umbilical arterial blood.

DESIGN

Randomised, double blind, placebo controlled trial.

SETTING

A regional perinatal referral centre.

PATIENTS

Mothers booked for ECS at or above 38 weeks gestation.

INTERVENTIONS

Thirty six consenting mothers were randomly allocated to receive either 2 mg intravaginal prostaglandin E(2) gel (study group; n = 18) or an equal volume of K-Y jelly as a placebo (control group; n = 18) 60 minutes before the ECS. Computer generated random numbers contained in coded, sealed envelopes were used for allocation. The obstetric and neonatal teams were blinded to the randomisation status of enrolled mothers.

MAIN OUTCOME MEASURES

Catecholamine concentrations in the umbilical arterial blood samples collected at delivery.

RESULTS

The median (interquartile range) neonatal gestation and birth weight were 271 (269-274) days and 3605 (3072-3970) g for the study group and 271 (270-273) days and 3340 (3000-3622) g for the control group. Median (interquartile range) noradrenaline (norepinephrine) concentrations in the umbilical arterial blood were significantly higher in the study group than the control group (15.9 (9.8-28.92) v 4.6 (1.65-14.4) ng/l, p = 0.03). Adrenaline (epinephrine) concentrations did not differ significantly between the two groups (1.6 (< 0.5-3.1) v 1.4 (< 0.5-2.75) ng/l, p = 0.6). No treatment related complications occurred.

CONCLUSION

A labour related catecholamine surge could be simulated by intravaginal prostaglandin E(2) gel.

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.

Trends and characteristics of induced labour in the United States, 1989-98

Induction of labour is one of the fastest growing medical procedures in the United States. In 1998, 19.2% of all US births were a product of induced labour, more than twice the 9.0% in 1989. Induction of labour has been efficacious in the management of post-term pregnancy and in expediting delivery when the mother or infant is sufficiently ill to make continuation of the pregnancy hazardous. However, the recent rapid increase in induction, and particularly the doubling of the induction rate for preterm pregnancies (from 6.7% in 1989 to 13.4% in 1998), has generated concern among some clinicians. The present study uses vital statistics natality data to examine the epidemiology of induced labour in the US. Multivariable analysis is used to examine the probability of having an induced delivery in relation to a wide variety of socio-demographic and medical characteristics, and also in relation to relative indications and contraindications for induced labour as outlined by the American College of Obstetricians and Gynecologists (ACOG). Induction rates were higher for women who were non-Hispanic white, college educated, born in the US, primaparae and those with intensive prenatal care utilisation. Induction rates were also higher for women with various medical conditions including hypertension, eclampsia and renal disease. For non-Hispanic white women with singleton births, 59% of the increase in the preterm birth rate from 1989 to 1998 can be accounted for by the increase in preterm inductions. The adjusted odds ratio for neonatal mortality among preterm births with induced labour was 1.20 [95% confidence interval 1.11, 1.31]. The rapid increase in induction rates, particularly among preterm births, marks a shift in the obstetric management of pregnancy. More detailed studies are needed to examine physician decision-making protocols, particularly for preterm induction, and to assess the impact of these practice changes on patient outcomes.

Uterine rupture after a single vaginal 2 mg prostaglandin gel application in a primiparous woman

We report a case of a primiparous woman who was induced for post-term pregnancy with 2mg intravaginal prostaglandin gel. She developed hyperstimulation and ruptured her uterus. The pathogenesis and treatment of hyperstimulation is discussed.

Uterine rupture

Uterine rupture is an uncommon obstetric event. It is important because it continues to be associated with maternal mortality, especially in developing countries, and with major maternal morbidity, particularly peripartum hysterectomy. It is also associated with a high incidence of perinatal mortality and morbidity worldwide. This chapter examines the incidence, aetiology, clinical presentation, complications and prevention of uterine rupture. The key factor in the cause of rupture is whether or not the uterus is scarred. Rupture of an unscarred uterus is rare, usually traumatic, and its incidence decreases with improvement in obstetric practice. Rupture of the scarred uterus is more common, and usually occurs after a trial of labour in a patient with a previous Caesarean section. This chapter also explores how the incidence and complications of uterine rupture may be minimized, and yet the incidence of vaginal birth after Caesarean section (VBAC) optimized, in clinical practice.

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.

Risk factors for uterine rupture during a trial of labor after cesarean

The rate of vaginal birth among women with a previous cesarean increased from 18.9% in 1989 to 28.3% in 1996. By 1998, the rate had decreased to 26.3% and preliminary data from 1999 suggest that the rate for that year would be even lower (23.4%). It is not known whether that decrease represents a trend related to increasing concern by providers and women about the risk of uterine rupture. Whereas the overall risk of rupture is 1%, our review demonstrates that there is considerable variation of that risk. More than one previous scar, induction of labor, a short interdelivery interval, or a history of postpartum fever during a previous cesarean may increase the risk of a uterine rupture during a trial of labor. However, there does not appear to be an increase in risk associated with low-vertical scars, and a previous vaginal delivery may be somewhat protective. Further delineation of the factors that increase the risk of uterine rupture will permit better prediction of individualized risk and identification of women for whom attempting a vaginal delivery after cesarean represents a safe option.

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.