Vaginal delivery after Caesarean section: factors influencing success rates

Middle eastern college of obstetricians and gynecologists (MCOG) practice guidelines: Role of prediction models in management of trial of labor after cesarean section. Practice guideline no. 05-O-22✰,✰✰,★,★★

Cesarean delivery rates have been steadily rising since the beginning of the 21st century. The growing incidence is even more prominent in developing countries owing to lack of evidence-based guidance and audit, and the expansion of private practice. The uprise in Cesarean delivery rate has been associated with considerable financial burden and has increased the risk otherwise uncommon serious complications such as placenta accreta disorders and uterine rupture. In addition to primary prevention of Cesarean delivery, trial of labor after cesarean section is one of the most successful strategies to reduce Cesarean deliveries and minimize risks associated with higher order Cesarean deliveries. This guideline appraises patient selection strategies and use of prediction model to promote counseling and enhance safety in women considering vaginal birth after Cesarean.

No. 382-Trial of Labour After Caesarean

OBJECTIVE

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

OUTCOMES

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

EVIDENCE

MEDLINE database was searched for articles published from January 1, 1995, to October 31, 2017 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.

VALIDATION

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

RECOMMENDATIONS

Factors associated with successful vaginal birth after a cesarean section: a systematic review and meta-analysis

BACKGROUND

Evidence for the relationship between maternal and perinatal factors and the success of vaginal birth after cesarean section (VBAC) is conflicting. We aimed to systematically analyze published data on maternal and fetal factors for successful VBAC.

METHODS

A comprehensive search of Medline, Embase, and the Cumulative Index to Nursing and Allied Health Literature, from each database's inception to March 16, 2018. Observational studies, identifying women with a trial of labor after one previous low-transverse cesarean section were included. Two reviewers independently abstracted the data. Meta-analysis was performed using the random-effects model. Risk of bias was assessed by the Newcastle-Ottawa Scale.

RESULTS

We included 94 eligible observational studies (239,006 pregnant women with 163,502 VBAC). Factors were associated with successful VBAC with the following odds ratios (OR;95%CI): age (0.92;0.86-0.98), obesity (0.50;0.39-0.64), diabetes (0.50;0.42-0.60), hypertensive disorders complicating pregnancy (HDCP) (0.54;0.44-0.67), Bishop score (3.77;2.17-6.53), labor induction (0.58;0.50-0.67), macrosomia (0.56;0.50-0.64), white race (1.39;1.26-1.54), previous vaginal birth before cesarean section (3.14;2.62-3.77), previous VBAC (4.71;4.33-5.12), the indications for the previous cesarean section (cephalopelvic disproportion (0.54;0.36-0.80), dystocia or failure to progress (0.54;0.41-0.70), failed induction (0.56;0.37-0.85), and fetal malpresentation (1.66;1.38-2.01)). Adjusted ORs were similar.

CONCLUSIONS

Diabetes, HDCP, Bishop score, labor induction, macrosomia, age, obesity, previous vaginal birth, and the indications for the previous CS should be considered as the factors affecting the success of VBAC.

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.

Delivery after prior cesarean: success rate and factors

Cesarean delivery rates in the United States have reached an all-time high. The current rate of 31% is 6 times higher than the 1970s rate. Many factors including physician preference and hospital accessibility account for this trend. A decreased vaginal birth after cesarean (VBAC) rate and an increased repeat cesarean rate have important consequences for women in future pregnancies. Because of these considerations, VBAC has been an important issue within the obstetric community for over 3 decades. Identifying the best candidates for VBAC using factors available to the obstetrician can increase the VBAC success rate while minimizing maternal morbidity.

Vaginal birth after one previous caesarean section in a tertiary institution in Nigeria

Vaginal birth after one previous lower segment caesarean section represents one of the most significant and challenging issues in obstetric practice. A 5-year retrospective study was carried out at the University of Benin Teaching Hospital between January 1999 and December 2003, to determine the incidence, the maternal and fetal outcome following vaginal delivery after one previous caesarean section with a view to evaluating its safety and efficacy. There were 5234 deliveries, with 395 cases of one previous caesarean section, giving an incidence of 7.5%. The incidences of emergency caesarean section, elective caesarean section and spontaneous vaginal delivery following trial of vaginal delivery were 34.7%, 9.4% and 48.1%, respectively. During the study period there were 1317 cases of caesarean section, giving an incidence of 25.2% caesarean section rate. The incidence of one previous section among all caesarean section births was 30%. The major morbidity following vaginal delivery was uterine rupture with an incidence of 1.5% and hysterectomy of 0.8%. Three of the uterine ruptures occurred before admission because the patients laboured at home. One maternal death occurred as a result of uterine rupture and postpartum haemorrhage, giving a maternal mortality ratio of 19/100,000 and a case fatality rate of 0.3%. The corrected perinatal mortality rate was 15.2/1000, mainly from obstructed labour, abruptio placenta and fetal distress. Both maternal and fetal mortalities from vaginal birth after one previous section were significantly less than the respective overall maternal and fetal mortality from the institution. The 1-minute apgar score of babies delivered by elective section was significantly (P < 0.001) higher than the apgar score of babies delivered by emergency section and vaginally. There was only one patient with wound dehiscence at elective section without associated perinatal death. Vaginal delivery following caesarean section is relatively safe. However, women in developing countries will continue to require counselling to counter the myths of aversion to operative delivery even at the expense of losing their lives. Our hospitals should have adequate monitoring equipment for high-risk pregnancies so that patients and their babies can be assured of survival.

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.

Maternal and perinatal complications with uterine rupture in 142,075 patients who attempted vaginal birth after cesarean delivery: A review of the literature

OBJECTIVE

The purpose of this study was to determine the rate of uterine rupture and its complications as the result of trial of labor after previous cesarean delivery.

STUDY DESIGN

PubMed was searched from 1989 to 2001, with the terms "VBAC, uterine rupture," "trial of labor, uterine rupture," "cesarean delivery, uterine rupture," and "scarred uterus, rupture." For inclusion, reports had to contain data from at least 100 patients with trials of labor that included a description of adverse outcomes. Duplicate reporting from a single institution was excluded. Odds ratios and 95% CIs were calculated.

RESULTS

Seventy-two of the 361 articles (20%) that were identified met the inclusion criteria. A 6.2 per 1000 trial of labor rate of uterine rupture (total=880 uterine ruptures in 142,075 trials of labor) was determined. For every 1000 trials of labor the uterine rupture-related complication rate was 1.8 for packed red blood cell transfusion, 1.5 for pathologic fetal acidosis (cord pH<7.00), 0.9 for hysterectomy, 0.8 for genitourinary injury, 0.4 for perinatal death, and 0.02 for maternal death. The perinatal mortality rate was significantly lower among studies from the United States versus other countries (0.3 vs 0.6; odds ratio, 0.50; 95% CI, 0.26-0.94) and in series that exceeded 1000 patients (0.2 vs 1.7; odds ratio, 7.34; 95% CI, 3.94-13.69).

CONCLUSION

Although relatively uncommon, uterine rupture is associated with several adverse outcomes, depending on the time of the publication and the site and size of the population that was studied.

Elective repeat cesarean delivery versus trial of labor: a meta-analysis of the literature from 1989 to 1999

OBJECTIVE

The aim of this study was to compare a trial of labor with elective repeat cesarean delivery among women with previous cesarean delivery.

STUDY DESIGN

We searched MEDLINE and EMBASE databases from 1989 through 1999 with the following terms: vaginal birth after cesarean delivery, trial of labor, trial of scar, and uterine rupture. We included all controlled trials from developed countries in which the control group had been eligible for a trial of labor. Outcomes of interest were uterine rupture, hysterectomy, maternal febrile morbidity, maternal mortality, 5-minute Apgar score <7, and fetal or neonatal mortality. We computed pooled odds ratios for each outcome.

RESULTS

The search strategy identified 52 controlled studies, 37 of which were excluded because many of the control subjects were not eligible for a trial of labor. Fifteen studies with a total of 47,682 women were included. Uterine rupture occurred more frequently among women undergoing a trial of labor than among those undergoing elective repeat cesarean delivery (odds ratio, 2.10; 95% confidence interval, 1.45-3.05). There was no difference in maternal mortality risk between the 2 groups (odds ratio, 1.52; 95% confidence interval, 0.36-6.38). Fetal or neonatal death (odds ratio, 1.71; 95% confidence interval, 1.28-2.28) and 5-minute Apgar scores <7 (odds ratio, 2.24; 95% confidence interval, 1.29-3.88) were more frequent in the trial of labor group than in the control group. Mothers undergoing a trial of labor were less likely to have febrile morbidity (odds ratio, 0.70; 95% confidence interval, 0.64-0.77) or to require transfusion (odds ratio, 0.57; 95% confidence interval, 0.42-0.76) or hysterectomy (odds ratio, 0.39; 95% confidence interval, 0.27-0.57).

CONCLUSION

A trial of labor may result in small increases in the uterine rupture rate and in fetal and neonatal mortality rates with respect to elective repeat cesarean delivery. Maternal morbidity, including febrile morbidity, and the need for transfusion or hysterectomy may be reduced with a trial of labor.

Induction of labour for trial of vaginal birth after caesarean section in a remote district hospital

In a retrospective review of 79 women with 1 or more previous Caesarean section, 33 (41.8%) women agreed to a trial of vaginal birth. Twenty nine women had labour induced and 26 (89.7%) of them had a successful vaginal delivery. Four women laboured spontaneously and 1 of them needed an emergency Caesarean section for failure to progress. The overall vaginal delivery rate for women selected to undergo a trial of vaginal birth after Caesarean was 87.9%. The overall emergency Caesarean section rate was 4 of 33 (12.1%). During the study period the Caesarean section rate for the hospital fell from 32.2% to 11%. This study suggests that induction of labour in women with a previous Caesarean section is very successful in achieving vaginal delivery and has a role to play in remote and rural hospitals.