The role of instrumental vaginal delivery in low resource settings

Authors


CA Ameh, Lecturer in Sexual and Reproductive Health, Maternal and Newborn Health Unit, Liverpool School of Tropical Medicine, Pembroke Place, Liverpool L3 5A, UK. Email caameh@liverpool.ac.uk

Complications of prolonged and obstructed labour cause 4–13% of maternal deaths in Africa, Asia, Latin America and the Caribbean.1 Several evidence-based interventions have been identified that are currently underused and that could prevent many of these deaths. These include instrumental vaginal delivery (IVD), external cephalic version, labour augmentation, the partogram, caesarean section, selective episiotomy, symphysiotomy and destructive procedures for nonviable fetuses.2–4

IVD with obstetric forceps or vacuum extractor is used to treat obstructed second stage of labour and presumed fetal compromise. Although it is a service provided in both basic and comprehensive essential (or emergency) obstetric care (EOC, Table 1), it is underused in low resource settings. A 3-year quality improvement programme in 73 health facilities in three districts in Malawi from 2005 to 2007 reported that of the EOC activities, assisted vaginal deliveries and manual vacuum aspiration were the least available.5 But this is not just an African problem. Worldwide, a 2006 study examined national attitudes towards vacuum extraction in 121 developing countries and found that the use of vacuum extraction was not universal.6 In Latin America and the Caribbean, for example, 17 of 23 countries (74%) never used or taught the technique. Rates in sub-Saharan Africa and Asia were higher, but still 40 and 30% of countries, respectively, never used or taught vacuum extraction. Overall, it was only used routinely in 48% of countries. Seventeen percent of countries never used or taught it and 37% restricted its use to specialists. Bailey in 2005 also reported low rates of instrumental vaginal deliveries (5% or less) from West Africa and Latin America.7 Where IVD is used in developing countries, vacuum extractors are most popular in Africa and Asia, while forceps are more popular in Eastern Europe and South America.8

Table 1.   Signal functions to be available at Basic and Emergency Obstetric Care health facilities18
Basic EOC servicesComprehensive EOC services
1. Administer parenteral antibiotics1-6 All those included in Basic EOC
2. Administer parenteral oxytocic drugs 7. Perform surgery (Caesarean section)
3. Administer parenteral anticonvulsants for pre-eclampsia and eclampsia 8. Perform blood transfusion
4. Perform manual removal of the placenta
5. Perform removal of retained products (e.g. manual vacuum aspiration)
6. Perform assisted vaginal delivery

The reasons for the low rates of IVD in low resource settings are not known. Over the last 100 years, IVD rates in the US and Europe have slowly increased for various reasons: the introduction of electronic intrapartum fetal monitoring and epidurals, the increasing proportion of nulliparous women, and the change in availability of equipment and trained operators. The increased caesarean section (CS) rate, however, has limited the rise in the IVD rate, partly because fewer women reach the second stage of labour and partly because CS is used as an alternative to rotational or mid cavity IVDs. All these factors are relevant when assessing the reasons for the low rate of IVD in low-resource settings, although their relative contributions vary. So in South America, the high rate of CS has a major effect, while in sub-Saharan Africa the problem is more one of a lack of skilled operators and equipment.9 There is also a vicious cycle, whereby low IVD rates reduce the opportunities for practice and training, and this reduces the rate even further. As a consequence, IVD rates are declining in many low resource settings.6,7,9

The instrumental delivery rate varies greatly between settings and the ideal rate is unknown. In developed countries, the rates vary from 10–15% in the UK10 to just 4.5% in the USA11 where its rate has halved in the last 20 years.7 Rates of under 1% are reported from sub-Saharan Africa.7 Lower rates would be expected in low resource settings because of the higher mean parity and the unavailability of epidural analgesia and electronic intrapartum fetal monitoring, but the lack of facilities providing IVD will also play a role. CS rates also have an effect, with the rate of IVD inversely proportional to the CS rate. Perhaps more important than the absolute number is the rate of ‘unmet need’ for the setting and the rate of complications of obstructed second-stage labour: stillbirths, uterine ruptures and vesico-vaginal fistulas.

In settings with high rates of unmet need, there is a clear need to make IVD more widely available. Achieving this will require specific interventions to increase the availability of both IVD equipment and operators skilled in its use. It is also dependant on general improvements like increasing the number of births attended by skilled birth attendants (SBAs) and making facilities for EOC more widely available.

The most frequently used instrument for IVD in resource-poor countries is the vacuum or ventouse. Forceps, while easy to maintain, are associated with higher rates of maternal trauma12 and require greater experience to use. Furthermore, the commonly used forceps can only be used for occipito-anterior head positions and these rarely require instrumental delivery in low resource settings. Vacuum deliveries, in contrast, result in higher rates of neonatal trauma, although these are generally mild and self limiting.12 The vacuum is also simpler to use as it is more tolerant of incorrect assessments of the fetal head position. This feature in theory makes it a safer instrument in relatively unskilled hands and it has therefore become the instrument of choice for many settings. However, the commonly available Malmstrom vacuum extraction equipment presents challenges of maintenance in resource poor countries. Common problems include outdated equipment, leaky tubes and broken vacuum bottles.6,7 Although most of the suction equipment is manual so as not to rely on a power supply, there are frequently problems with broken hand or foot pumps.

A more recent design for the vacuum extractor is the rigid plastic cup Kiwi® vacuum assisted fetal delivery device (Clinical Innovations, Murray, UT, USA). It was designed as an integrated unit without the need for a separate vacuum device—the suction is provided by a small hand pump which is integral to the traction handle. The disposable Kiwi OmniCup® is the most commonly available version with an ingenious cup design that makes it suitable for occipito-anterior, -lateral or -posterior positions. Randomised trials comparing the OmniCup to traditional designs have shown a higher proportion of failures due to ‘pop-offs’, a problem attributed to the small cup volume in early designs.13,14 The manufacturers state that this problem has been overcome by changes in the design with the addition of a pressure chamber along the traction cord, but the randomised trials have not been repeated. Recently the OmniCup® has also become available in a reusable version suitable for resource-poor settings. The relatively low cost and portability of the reusable OmniCup® are attractive features, but maintenance and repair is unlikely to be as easy as for the Malstrom and its portability may make it an easy target for thieves. The balance of cost between the two systems is therefore, at present, unclear.

The development of the re-usable OmniCup could help to solve some of the equipment problems in resource poor countries, but where the Malstrom version is used a system of maintenance should be put in place. Manufacturer should increase the longevity of the Malstrom equipment by providing plastic rather than glass bottles and including replacement parts for the vacuum production unit with each set.

The more difficult problem to solve is the lack of skilled operators. A recent systematic review on human resources and the quality of EOC in developing countries concluded that staff shortages are a major obstacle to provision of good quality EOC.15 IVDs have traditionally been conducted by medical doctors alone and in some places, there has been reluctance to allow non-doctors to share their skills. Indeed this is ironic given that the early history of forceps was marked by attempts to restrict their use to a closed body—first by the Chamberlen family and then by a group of French Obstetricians.16 But if the rate of instrumental deliveries is to be increased to even double its current rate, it is clear that non-doctors have to be trained to conduct these deliveries. This is in line with other international strategies to empower mid level providers.17

A skilled birth attendant (SBA) is defined as an accredited health professional (i.e. a midwife, doctor or nurse) who has been educated and trained to proficiency in the skills needed to manage normal (uncomplicated) pregnancies, childbirth and the immediate postnatal period, and in the identification, management and referral of complications in women and newborns.17 Skilled care at birth is recommended for all deliveries and SBAs should be able to recognise and initially manage the common obstetric complications.17,18 The WHO recommends that skilled attendants working at the primary care levels in remote areas with limited access to facilities should also be able to use vacuum extraction or forceps in vaginal deliveries.17 But this may not extend to ‘mid or high cavity’ deliveries, primarily because of the lack of CS facilities. Such procedures have a greater risk of failure and in well-resourced settings, it is recommended that they should be conducted where there is immediate recourse to caesarean section if needed.10,19 Instrumental deliveries conducted in basic EOC facilities should therefore be outlet or low vaginal deliveries only, although it is recognised that these rules will need to be flexible according to the resources available.

Many countries already train SBAs to conduct vacuum deliveries, but this training needs to be extended if the rate of unmet need is to be reduced. Achieving this will take political will, which will only be achieved by increasing advocacy at professional associations and ministries of health on the safety and usefulness of the vacuum extractor. Following this, country-specific interventions will need to be put in place to ensure that competent SBAs are trained, deployed to where they are most needed and then retained. This will require a curriculum that includes IVD skills and basic guidelines. These should support the use of simple, cost-effective equipment for low cavity or outlet deliveries based on evidence-based materials such as the WHO Integrated Management of Pregnancy and Childbirth20 and the Reproductive Health Library.21 An excellent teaching video is available freely on the RHL website (http://apps.who.int/rhl/videos/en/index.html).

Whoever conducts the delivery, high quality training is crucial. Complications are generally reported to be minimal when operators are properly trained and the correct equipment is selected.10 There is evidence that formal education and training improves the outcome of instrumental delivery, reducing the rate of both maternal and neonatal morbidity.22 Continuing medical education techniques which are interactive (case discussions and hands-on practice sessions using models) and the use of mixed educational sessions (obstetricians, midwives and SBAs) are beneficial and should be promoted for in-service training.22,23 This method of skills training may present new challenges to the cash strapped health systems of resource poor countries.

IVD is a key element of essential obstetric care whose role has often been undervalued. Improving maternal and neonatal outcomes will require the scaling up of IVD use, with the provision of equipment and trained operators to areas where they are currently unavailable. Achieving this will take a concerted campaign. But obstructed labour in the second stage carries with it such a high cost for mother and baby that it is well worth doing.

Conflict of interest

Andrew Weeks has been working with the UK distributers of the Kiwi ventouse cup (Clinical Innovations Europe Ltd) to develop the StationMaster, a device to measure the fetal head station in labour. CI funded the initial production of the device for clinical trials, although AW has received no direct payments from them. Charles Ameh has no conflict of interest and nothing to declare.

Funding

The authors have received no funding for this commentary.

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