SEARCH

SEARCH BY CITATION

For more than 30 years, planned vaginal birth after caesarean section (VBAC) has been offered as an option to women with prior caesarean section. This was mainly driven by the need to lower the rising rates of caesarean section. A consensus meeting between the National Institutes of Health (NIH) and World Health Organization (WHO) concluded that the rate of caesarean section was too high, and VBAC was therefore seen as an acceptable alternative to elective repeat caesarean section (ERCS). This approach was partially motivated by the reported success rates and safety of VBAC.[1] At the time, this statement was applicable to developed countries, as resource-poor areas were yet to register significant caesarean section rates to warrant such interventions; however, recent demographic data indicate that the practice of planned VBAC is now prevalent in most maternity units in Africa.[2, 3]

The deficiencies in delivery of health services in most low-income countries are common knowledge. The region also bears the greatest burden of maternal and perinatal morbidity and mortality. Therefore, the main concern is whether planned VBAC can be safely offered to women in this region, bearing in mind the scarcity of essential resources, without further worsening the already poor perinatal outcomes. Unfortunately, most of the information on the subject is derived from demographic health surveillance data, and consequently the outcome of VBAC in the region is poorly understood.[3]

The overall rate of caesarean section in sub-Saharan Africa (SSA) is still very low; however, it remains the most common operation performed in the region, and there is an upward trend as more women gain access to this lifesaving procedure.[3] Consequently, the proportion of women with scarred uteri as a result of caesarean section is inevitably on the rise. Considering the high birth rates, bigger family size, and low contraceptive coverage in this region, the chances of these women having subsequent pregnancies is very high.[2] Clinicians and policy makers therefore need to be well prepared to advise and formulate appropriate delivery plans suitable for these women without compromising their safety.

Whereas planned VBAC may be an option, it is not as safe as it was originally thought to be. To the contrary, evidence indicates that ERCS is safer than unsuccessful VBAC. The major maternal complications associated with unsuccessful VBAC include uterine rupture, hysterectomy, venous thromboembolism, haemorrhage, transfusion requirements, visceral injury, and maternal death. Most of these complications can be averted by offering the woman an ERCS. Compared with those who opt for ERCS, women undergoing planned VBAC are at a greater risk of severe haemorrhage requiring blood transfusion (170/10 000 versus 100/10 000) and postpartum endometritis (289/10 000 versus 180/10 000). This equates to an increase in transfusion needs and postpartum uterine infection of 0.7 and 1.1%, respectively.[4] Of concern is the fact that obstetric haemorrhage and infection account for almost half of maternal deaths in SSA, and efforts to reduce this have been elusive for decades.[5] Further data from SSA indicate that more than 15% of emergency caesarean sections performed on scarred uteri will require blood transfusion, and these needs are doubled in the event of uterine rupture.[6] Most facilities in low-income countries lack sufficient blood products, and therefore allowing women to undergo VBAC will further increase morbidity and mortality, rather than prevent it. This situation is further worsened by poor antenatal care and suboptimal birth preparedness. For instance, it is known that the incidence of placenta praevia is high in women with previous caesarean section. This is a well-recognised cause of antepartum haemorrhage, with potential risk of fatality.[7] Most women in low-income countries will go through pregnancy without an obstetric ultrasound and placenta praevia may be not be suspected at all, especially in those who remain asymptomatic. Furthermore, in the absence of an obstetric ultrasound it is difficult to exclude multiple gestations and the presence of pelvic pathology, such as uterine fibroids, which are inadvertently prevalent among women of African origin. These have the potential to not only interfere with the progress of labour but also predispose women to excessive postpartum bleeding. In view of the fact that obstetric haemorrhage and infection are major causes of maternal death in Africa,[5] unsuccessful VBAC would therefore significantly raise the absolute risk for these two conditions.

One may argue that because these complications are mainly associated with unsuccessful VBAC they are unlikely to arise, bearing in mind the relatively high success rate of VBAC; however, the universal success rate of 72–76% often quoted is based on data from individual studies, where success was measured in terms of vaginal delivery, regardless of the ensuing complications.[4] Furthermore, most of the centres where these studies were undertaken had the capacity to handle any emergencies that could arise; consequently, the practice was seen to carry fewer complications. These findings, which were mostly from high-income countries, have since been adopted by obstetric units in most low-income countries and planned VBAC is universally offered as an alternative to ERCS. The practice was fostered by the results of a meta-analysis performed more than 15 years ago. Boulvain et al.[8] reported a success rate of 69% (95% CI 63–75%) in their review, and concluded that VBAC in SSA was as safe as in the developed countries, despite the difficult clinical conditions and resource limitations. However, this analysis was mainly based on findings from retrospective observational studies with mixed measures of outcomes, diagnostic criteria, different institutional profiles, and varying management protocols. The obvious heterogeneity among the studies included in this meta-analysis was not considered in making the final recommendations. The assertion that the safety and success of planned VBAC in low-resource settings is similar to that in developed countries is therefore incorrect. Unfortunately, there have been very few follow-up studies on the subject since this review. Most information has subsequently been inferred from demographic surveillance data, and is not very reliable in establishing a causal relationship.[2, 3]

According to the Royal College of Obstetricians and Gynaecologists (RCOG), for a planned VBAC to be considered safe stringent criteria must be fulfilled. The practice is not recommended in women with a previous uterine rupture, high vertical uterine incision, and in cases with three or more previous surgeries. The college further recommends the use of continuous electronic fetal monitoring, and institutional ability to perform emergency caesarean section and provide blood transfusion is mandatory.[7] Even though this guidance is intended for use in the UK, it is globally applicable from a patient safety point of view and a similar strategy should be adopted whenever planned VBAC is contemplated, regardless of the setting.

Besides being unable to continuously monitor women in labour, there is often a lack of information on the previous operations because of poor record keeping in most maternity units in SSA.[3] This hampers most institutions from meeting the minimum standards required to offer safe planned VBAC. This is a view shared by midwives and obstetricians in East Africa, who despite having a policy to offer VBAC in their units still perceived the practice as suboptimal and a major risk to maternal safety.[9]

Previous efforts to promote VBAC have been motivated by the need to reduce the rising rates of caesarean section.[1] This may not be justified in SSA as the rates are too low to rationalise any aggressive efforts at reducing them further, especially if in so doing the safety of the woman and the baby is compromised. The high perinatal morbidity and mortality in this region negates such interventions, considering that caesarean section significantly improves outcomes. As there are data to support the safety of elective caesarean section in Africa, ERCS should take precedence over VBAC. This is supported by findings from the global survey on maternal and perinatal health in Africa. In this study, elective caesarean section was associated with less maternal morbidity, lower rates of severe neonatal morbidity, and fewer fresh stillbirths, compared with emergency caesarean section, especially in women with prior caesarean delivery.[10]

Efforts to ensure safe VBAC, such as the provision of electronic fetal monitoring and blood transfusion services, may not be realised soon if the low budgetary allocations to health care by most African governments are to be considered a benchmark for the capacity to improve health infrastructure in the continent. The capability to provide safe blood products is further curtailed by the high prevalence of HIV infection in the region.[2] Improving the availability, accessibility, and quality of caesarean section may be preferable and easier to achieve. With up to 85% of facilities being able to offer elective caesarean section, initiatives to train more personnel will further increase the availability and safety of the procedure, with fewer additional resources.[10] Strategies similar to those tried in Mozambique, where non-physician mid-level healthcare providers are trained to perform caesarean section, could be adopted in other countries experiencing a scarcity of human resources. This initiative has proven to not only lower the cost of caesarean section significantly but also improve the perinatal outcomes, especially in remote areas. Further analysis of the programme confirms that it is sustainable in the long term, as this cadre of workers is easy to retain in rural areas without compromising quality of care.[11] Instrumental delivery remains unpopular in Africa. Training, equipping, and empowering midwives to perform vacuum and forceps deliveries is another strategy that could significantly contribute towards improving maternal and perinatal health in the continent, while minimising the risk of primary cesarean section performed in the second stage of labour.[12]

As poor antenatal care and low socio-economic standards are major contributory factors to uterine rupture in women with previous caesarean section, they must be addressed if the region is to achieve any meaningful gains in perinatal outcomes in women with scarred uteri. High-quality antenatal care and good record keeping are regarded as effective interventions in reducing maternal and perinatal morbidity and mortality, because they facilitate the early identification of high-risk pregnancies and lead to better care.[13]

Overall, caesarean section if carefully performed improves maternal and perinatal outcomes; however, it becomes an additional risk factor in subsequent pregnancies. Paradoxically, this risk may be averted by electively repeating a caesarean section rather than attempting a VBAC. Should an operation be needed the benefits are only realised if the operation is performed sooner rather than later in labour.[10] Increasing contraceptive coverage to enhance birth spacing and reduce the size of families could be an effective measure in reducing the additional risk, as caesarean delivery becomes inevitable for these women in subsequent pregnancies.

In conclusion, planned VBAC may be considered a safe delivery option for women with previous caesarean section in high-income countries; however, this does not apply to the developing world, as it could further amplify the absolute risk for maternal and perinatal mortality among women, taking into consideration the pre-existing background risk. Bearing in mind the low rates of caesarean section across SSA there is no justification to adopt measures to reduce rates any further, especially if in doing so the health of women is compromised. Efforts should instead be directed towards making elective caesarean section readily available and accessible to all women, while putting in place reasonable measures to prevent unnecessary primary caesarean deliveries.

Disclosure of interests

The authors report no conflicts of interest to disclose.

Contribution to authorship

SZW conceived the original idea. Both authors participated in the literature review and discussed the findings. Both SZW and SKN read and approved the final article.

Details of ethics approval

Not required.

Funding

None.

References

  1. Top of page
  2. References
  • 1
    World Health Organisation. Appropriate technology for birth. Lancet 1985;2:4367.
  • 2
  • 3
    Stanton CK, Dubourg D, De Brouwere V, Pujades M, Ransman C. Reliability of data on caesarean section in developing countries. Bull WHO 2005;8:44955.
  • 4
    Landon MB, Hauth JC, Leveno KJ, Spong CY, Leindecker S, Varner MW, et al. Maternal and perinatal outcomes associated with a trial of labour after prior caesarean delivery. N Engl J Med 2004;351:25819.
  • 5
    Khan KS, Wojdyla D, Say L, Gülmezoglu AM, Van Look PFA. WHO analysis of causes of maternal death: a systematic review. Lancet 2006;367:106674.
  • 6
    Kwawukume EY. Poor antenatal attendance, lack of blood products. Best Pract Res Clin Obstet Gynaecol 2001;15:16578.
  • 7
    Royal College of Obstetricians and Gynaecologists. Birth after Previous Caesarean Section. Green-Top Guideline No. 45. London, UK: RCOG, 2007.
  • 8
    Boulvain M, Fraser WD, Brisson-Carroll G, Faron G, Wollast E. Trial of labor after caesarean section in sub-Saharan Africa: a meta-analysis. BJOG 1997;104:138590.
  • 9
    Wanyonyi ZS, Mwaniki AM, Stones W. Perspectives on the practice of vaginal birth after caesarean section in East Africa. East Afr Med J 2009;87:48.
  • 10
    Shah A, Fawole B, M'Imunya JM, Amokrane F, Nafioue I, Wolomby J, et al. Cesarean delivery outcomes from the WHO global survey on maternal and perinatal health in Africa. Int J Gynecol Obstet 2009;107:1917.
  • 11
    Cumbi A, Pereira C, Malalane R, Vaz F, McCord C, Bacci A, et al. Major surgery delegation to mid-level health practitioners in Mozambique: health professionals' perceptions. Hum Resour Health 2007;5:27.
  • 12
    Stones W, Obura T, Mukaindo M, Loeffler M, Warfa K. Evaluation of Vacuum Delivery Services in Kenya. Nairobi, Kenya: The Division of Reproductive Health, Ministry of Medical Services/Unicef, 2008.
  • 13
    Wen SW, Rusen ID, Walker M, Liston R, Kramer MS, Baskett T, et al. Comparison of maternal mortality and morbidity between trial of labor and elective caesarean section among women with previous caesarean delivery. Am J Obstet Gynecol 2004;191:12639.

Commentary on ‘Safety concerns for planned vaginal birth after caesarean section in sub-Saharan Africa’

This article raises an important issue. As elective repeated caesarean section (ERCS) is a major contributor to the rising rates of caesarean section, it is necessary to evaluate vaginal birth after caesarean section (VBAC), particularly in the context of sub-Saharan Africa (SSA).

Given the fertility rate in SSA, an ERCS will be followed by ERCSs for several other deliveries, with increasingly higher complication risk. Conversely, the benefit of a successful VBAC for the second child will carry over for subsequent pregnancies.

Another significant consequence of ERCS is the occurrence of placenta praevia or placenta accreta. Their incidence is higher with a history of caesarean section, and increases with the number of caesarean sections (ACOG Committee Opinion 529, 2012). The mortality rate of women with placenta accreta is high (7% in well-equipped hospitals) and management is complicated (surgery and massive blood transfusion). In contrast, uterine rupture during a trial of VBAC is associated with poor healing of the previous scar, poor vascular supply, and a relatively small blood loss for the mother.

The risks of the two alternatives (ERCS versus VBAC) should be compared over a woman's lifetime, rather than restricted to the second delivery. In the case of an attempt at VBAC after one caesarean section, the risk of uterine rupture may be estimated at 1–2% (with severe morbidity in less than 1%) and the likelihood of successful VBAC may be estimated at 70%. The risk of placenta praevia increases with the number of caesarean sections (none, 0.3%; one and two, 1.5%; more than two, 10%; calculated using data from Ananth et al. Am J Obstet Gynecol 1997;177:1071–80). The risk of placenta accreta in the case of placenta praevia increases from 3% with a history of one caesarean section to 61–67% with a history of five caesarean sections or more. After a successful VBAC, the risk of uterine rupture or of caesarean section in future deliveries is quite low, and the risk of placenta accreta is very low (0.05%) for each delivery. With a policy of ERCS the risk of this severe morbidity may be low for the second caesarean section (0.05%), but increases sharply for the third (1%), fourth (4%), and fifth or more (6%) pregnancies. If the average size of the family is four or more children, the risk of severe morbidity is clearly higher with a policy of ERCS, compared with a policy of trial of VBAC.

Moreover, the acceptability of caesarean section is poor in many African countries (Koigi-Kamau et al. East African Medical Journal 2005;82:631–6). If the hospital policy is to perform elective caesarean section for all with history of caesarean section, women may be reluctant to deliver in hospital and attempt VBAC at home, without access to urgent care.

The incidence of placenta praevia and placenta accreta will increase in SSA if a policy of ERCS is adopted. A policy of attempt at VBAC is safer. These policies should be individualised and implemented with proper surveillance, and with the availability of emergency caesarean section, blood transfusion, and prevention of infection.

Disclosure of interests

We have no conflict of interest to declare.

  • M Boulvain, A-C Benski & N Jastrow

  • Department of Gynecology and Obstetrics, University Hospitals of Geneva, Geneva, Switzerland