Printer Friendly

What evidence supports the use of free-standing midwifery led units (primary units) in New Zealand/Aotearoa?


There are many choices for parents when a pregnancy is confirmed, one of which is deciding on where to give birth. In New Zealand/Aotearoa women have the choice of giving birth at home, in a free standing midwifery led unit (FMLU), known in New Zealand as a primary maternity unit, or an obstetric unit (OU) known in New Zealand as a secondary or tertiary maternity unit. However, there are some regions of New Zealand that do not have free standing midwifery units (FMLUs) so women's choice is reduced to either home or an Obstetric Unit (OU). In 2009 there were 52 primary maternity units (FMLUs) in New Zealand most of which are situated in rural or provincial towns although there are several situated within main cities but are still free standing and separate to an obstetric unit (Hendry, 2009; Ministry of Health, 2012a). A primary unit is defined as:

"A community-based birthing unit, usually staffed by midwives. Primary birthing units provide access for women assessed as being at low risk of complications for labour and birth care. They do not provide epidural analgesia or operative birth services" (Ministry of Health, 2011a, p. 31).

Primary units are midwife led units which are physically separate (and often some distance) from obstetric units. For this paper the term FMLU will be used to replace primary unit so as to support consistency with international language. FMLUs provide midwifery led care for women who are well and healthy considered low risk and suited to birthing environments that are relaxed and home like. They are also more likely to be close to women's homes, therefore community based with familiar surroundings, which may have cultural significance for many families/ whanau. It has been argued that midwives need to support and utilise FMLUs because women are more likely to birth normally in these units (Skinner & Lennox, 2006).

Despite this encouragement, many of the FMLUs in New Zealand are reporting low bed occupancy levels whilst OUs are full and often oversubscribed (Canterbury District Health Board, 2012). In 2010, 12.5% of women who had a midwife Lead Maternity Carer (LMC) who was also a member of the Midwifery and Maternity Provider Organisation (MMPO) gave birth in a FMLU (primary unit) compared to 46.9% in a secondary unit (OU) and 35.4% in a tertiary unit (OU) (New Zealand College of Midwives & Midwifery and Maternity Provider Organisation, 2011). So whilst FMLUs are often available and provide an option for women to birth in their local community, the majority of women in New Zealand are actually giving birth in an obstetric unit. It is not known what role midwives play in the choice of birth place for women.

The choice of birth place is clearly not just dependent on availability but is often a deeply personal decision influenced by both rational and non-rational considerations. These can include influences such as culture, tradition, perceptions of safety, media, fear, previous experiences and the views and expectations of family/whanau and friends (Houghton, Bedwell, Forsey, Baker, & Lavender, 2008; McCourt, Rance, Rayment, & Sandall, 2011). The majority of research exploring choice of birth place has focused on why women choose to give birth at home. There is currently little research exploring the reasons why women do not choose to give birth in FMLUs in New Zealand or whether midwives promote their use.

In the United Kingdom there are a similar range of settings for women to consider when choosing a place of birth. These settings are home, FMLUs alongside midwifery led units (AMLU) and obstetric units (Redshaw, et al., 2011). Alongside midwifery led units are situated within or on the same site as an obstetric unit but care provision is led by midwives. These options are not fully available in all regions with FMLUs more available in the South West of England than elsewhere.

UK research has found that women's view on place of birth is influenced by safety, previous birth experiences, the influences of friends, family and doctors, social class and cultural values (McCourt, et al., 2011). Drivers for choosing hospital birth were access to epidural for pain relief and not needing to be transferred during labour if there was a problem. Women reported being prepared to travel up to two hours from a rural location to their preferred place of birth, and often associated consultant led (obstetric) units with increased safety (Pitchforth, et al., 2008). Often women were unaware of different options and considered that giving birth in an obstetric unit was the norm and a safe environment (Houghton, et al., 2008).

With so many women giving birth in an obstetric unit despite the availability of FMLUs in New Zealand it is likely that women are basing their decisions on similar concerns about safety as in the UK. What is the evidence that supports increased safety of obstetric units when compared to free standing midwifery led units? There have been several structured reviews examining the outcomes and cost effectiveness of FMLUs to ascertain the benefits and harms of these units (Henderson & Petrou, 2008; Stewart, McCandish, Henderson, & Brocklehurst, 2004; Walsh & Downe, 2004). These reviews found that in general women who birthed in FMLUs were more likely to birth normally with less intervention, but that there was a lack of conclusive evidence about neonatal mortality and morbidity. The reviews recommended more research be conducted using robust study designs that would support confidence in the reliability of the findings and in order to provide information to women about the safety of all birth place settings.

The Birthplace in England Collaborative Group have recently published the results of a large well conducted prospective cohort study involving 64,538 women aimed at comparing the perinatal outcomes, maternal outcomes, interventions during labour and the costs for the various options of birthplace in the United Kingdom (Birthplace in England Collaborative Group, 2011). The authors conclude that women planning birth in a FMLU experience fewer interventions than those planning birth in an OU with no impact on perinatal outcomes. This research is being used to provide evidence based information to women and support for low risk women to give birth in free standing midwife led units in England.

The maternity model of care in England, whilst similar to that of New Zealand, also has some differences. The authors of the Birthplace England study caution that their findings may not apply to countries where care is provided differently. So what are the similarities and differences between the UK and New Zealand? Both countries have midwives providing primary care in the community, both have fully funded maternity services, both support choice for women and both provide a choice of birth place which includes FMLUs for intrapartum care. In New Zealand women have universal access to the same midwife from antenatal care through the labour and birth and into the postnatal period. In England this type of continuity of care is less common and universal access to a known midwife is not the usual practice. This means that when transfer of care between units is necessary the women do not generally have a midwife stay with them and continue care in the obstetric unit. This continuity of care may have an impact on birth outcomes.

We considered it timely to critically review the evidence relating to the safety of FMLUs and to consider the relevance of those findings to the New Zealand context. Previous reviews of studies published prior to 2004 reported limited evidence on perinatal morbidity and mortality and poor study designs (Stewart, et al., 2004; Walsh & Downe, 2004). Our focus was to identify research studies that have been published since 2004 and in which outcomes could be considered transferrable to or are from the New Zealand context. Our research questions were: What is the evidence of safety for FMLUs and how does this evidence fit the New Zealand context? This paper provides the results of a structured literature review which aimed to identify, compare and critically evaluate published studies on FMLUs to determine the evidence that contributes to safety and may be useful for the New Zealand maternity context.


The primary objective of this structured literature review was to assess the elements of maternity care that contribute to safety for the woman and baby. Therefore the search strategy was designed to find all research studies on maternal and/or neonatal outcomes for births planned for free standing midwifery led units. Specific outcomes included interventions during labour, mode of birth, maternal morbidity such as Post Partum Haemorrhage (PPH), 3rd or 4th degree tears and episiotomy, perinatal mortality and morbidity such as stillbirth and neonatal mortality, Neonatal Intensive Care Unit (NICU) admission and low Apgar score

Search Strategy

The authors identified five databases to be searched to ensure a comprehensive review of the literature. Meta-searches of four databases were undertaken Cinahl, Embase, Medline and Pubmed. An additional database Scopus was searched separately. Key words used were place of birth, midwife-led, primary unit, maternal outcomes and neonatal outcomes. Identified studies were also hand searched for further references. Results were restricted to English language, peer reviewed papers and for the years 2004 to 2012.


The search resulted in 2322 hits with 84 full abstracts reviewed and 11 full texts retrieved and assessed (figure 1). All identified studies were assessed separately by two authors then discussed together. Studies were selected if they provided maternal or neonatal outcomes.

Excluded Studies

Eight studies were excluded; six of these described outcomes for alongside midwifery units in Ireland, Norway, China, and Australia (Begley, et al., 2011; Bernitz, et al., 2011; Cheung, et al., 2011; Eide, Nilsen, & Rasmussen, 2009; Laws, Tracy, & Sullivan, 2010; Tracy, et al., 2007).


A further two described outcomes for midwifery led care as opposed to place of birth (Table 1) (Maassen, et al., 2008; Symon, Winter, Inkster, & Donnan, 2009).

Included Studies

Three studies were included which met our search objectives (Table 2). This review has included one prospective cohort study from the UK, a prospective cohort study from Denmark and a retrospective observational study from New Zealand (Birthplace in England Collaborative Group, 2011; Davis, et al., 2011; Overgaard, A Moller, Fenger-Gron, Knudsen, & Sandall, 2011).


Overview and Quality assessment of included studies

Birthplace in England Study

The aim of the Birthplace in England study was to compare perinatal outcomes, maternal outcomes and interventions during labour by planned place of birth at the start of labour for women with low risk pregnancies (Birthplace in England Collaborative Group, 2011). It was a prospective cohort study involving 64,538 eligible women who were classified as low risk. This national study collected data for women who gave birth in one of the following places: at home, in a FMLU, an ALMU or an OU. Data was collected between April 2008 and April 2010. The results found no significant differences in the adjusted odds (1.00 OU, 1.59 Home, 1.22 FMLU, 1.26 AMLU) of the primary outcome (a composite of perinatal mortality and intrapartum related morbidities) for any of the non-obstetric unit settings compared with obstetric units (Table 3). Interventions during labour were substantially lower in all of the non-obstetric settings (these included homebirth, FMLU & AMLU). There were differences between nulliparous and multiparous women's outcomes depending on place of birth. Nulliparous women who planned to birth at home had an increased odds ratio (OR 2.80, 95% CI 1.66-4.76) for the primary outcome when compared to nulliparous women who planned to birth in a FMLU (OR 1.40, 95% CI 0.76-1.96). Additionally transfers from non-obstetric unit settings were more frequent for nulliparous women.

This study was able to compare outcomes by the woman's planned place of birth at the start of labour and had high participation rates from all the maternity units and hospitals in England. It also had a large sample size with sufficient statistical power to detect clinically important differences in adverse perinatal outcomes. Selection bias was minimised owing to a high response rate and there was the ability to compare groups that were similar for identified clinical risk. A weakness of the study was the use of a composite of perinatal outcomes, both mortality (perinatal death) and morbidity (neonatal encephalopathy, meconium aspiration syndrome etc) outcomes were used. This was because of the low rate of events for individual perinatal outcomes, but putting these two outcomes together may have concealed important differences between planned places of birth. The generalisability of the findings to other settings is problematic as models of maternity care may differ.

Danish Study

The objective of the Danish study was to compare the perinatal and maternal morbidity and birth interventions in low-risk women who planned to give birth either in one of two FMLU or in two OU's (Overgaard, et al., 2011). This was a prospective study involving a cohort of 839 low risk women who planned to give birth in a FMLU. Participants in the study were matched for age, ethnicity, parity and other factors and compared to a control group of 839 low risk women who gave birth in an OU (Overgaard, et al., 2011). The results indicated no increase in perinatal morbidity (poor Apgar scores, admittance to NICU, asphyxia) but significant reductions in caesarean section and increased likelihood of spontaneous vaginal birth for women with low- risk pregnancies who planned to give birth in a FMLU (Table 4). As a prospective cohort study this research had rigorous processes and well defined criteria to ensure that the outcomes for low-risk women were provided. The research was carried out in the same region so there was reduced risk of cultural or regional variances. A complete set of data was obtained and the cohorts were matched and adjusted to reduce the influences of confounding factors. However, the risk of confounding by unknown factors persists because of the study design.

New Zealand study

The New Zealand study was a large retrospective cohort study describing mode of birth according to birth place settings and intrapartum and perinatal outcomes using data extracted from the Midwifery and Maternity Provider Organisation (MMPO) database (Davis, et al., 2011). The MMPO is an organisation which supports self employed LMC midwives to manage their practice. It assists midwife members with payment claims and collects summary data based on the clinical information submitted by midwives. The database provides national data collected prospectively for a large number of women who birth in New Zealand. In this research study the cohort involved 16,453 low- risk women who gave birth between 2006 and 2007 and who planned to birth at home, in a FMLU (primary unit) or in an OU (secondary/tertiary unit). The results demonstrated that low-risk women planning to birth in a secondary or tertiary hospital had a high incidence of cesarean section, assisted births and other interventions when compared to women planning to birth at home or in a FMLU (Table 5). Additionally, women planning to birth at home or in a primary unit had less incidence of the baby being admitted to a neonatal intensive care unit.

The observational research design of this study increases the possibility for selection bias and there is a possibility that confounders (such as Body Mass Index (BMI) and socio-economic status which were not defined) could have had an influence on outcomes. Additionally, when there are multiple comparisons being made from a large database it is possible that some results may reach significance by chance. However, the level of significance for many of the outcomes this study measured were at the level of 0.001 or less thereby reducing chance outcomes to one in a 1000. The study was not powered to detect differences in perinatal mortality.


Maternal outcomes

Interventions during labour

The Birthplace in England study found women had less intervention during their labour and birth when they planned to birth in a FMLU compared with women who planned to birth in an OU (Table 3). The results included women whose planned place of birth changed during labour. They found reduced rates of syntocinon augmentation, reduced rates of epidural and general anaesthesia and increased use of water immersion and non active third stage. The Danish study also reported lower rates of oxytocin augmentation and epidural anaesthesia and increased use of water for pain relief for low-risk women who planned to birth in a FMLU (Table 4). The New Zealand study found significantly higher levels of intervention for women who birthed in a secondary or tertiary unit. The primary unit was used as the reference point in the analysis. The tertiary units had an adjusted relative risk of 1.87 (CI 95% 168-208 P < 0.001) for augmentation during labour as well as increased risks for artificial rupture of membranes and pharmacological pain management (Table 5).

Mode of birth

The England birthplace study reported higher rates of spontaneous normal vertex birth (90.7%) for women who planned to birth in FMLUs and higher rates of operative births for women who planned to birth in an OU (Table 3). The Danish study also reported higher normal birth rates (94.9%) and lower operative births for women who planned birth in a freestanding midwifery led unit (Table 4). The New Zealand study similarly found higher rates of vaginal birth for low-risk women who gave birth in a primary unit (94.7%) compared to low-risk women birthing in secondary units (84.5%) and tertiary units (72.7%).

Maternal morbidity

Maternal morbidity outcomes for each study varied with some overlap between studies. The Birthplace England study reported reduced rates of third and fourth degree tears for women who planned to birth in a FMLU. The Danish study also reported reduced rates of third and fourth degree tears and PPH although the differences between units for PPH of more than 1000mls were not significantly different (Table 4). The New Zealand study found that the adjusted relative risk of episiotomy for women who planned a tertiary unit birth was 2.91 (CI 95% 2.37-3.57) times that for a woman planning a primary unit birth. For PPH of more than 1000mls, the adjusted relative risk for a woman planning a tertiary unit birth was 1.39 (CI 95% 0.90-2.16) times that of a woman planning a primary unit birth.

Neonatal outcomes

The UK birthplace study reported on the perinatal mortality and morbidity for the whole cohort as 4.3 per 1000 (CI 95% 3.3 - 5.5). This included outcomes such as stillbirth, early neonatal death, neonatal encephalopathy, meconium aspiration syndrome, brachial plexus injury, fractured humerus or clavicle as an adverse event. For women without any complicating conditions at the start of labour, the rate of adverse events was 3.1 per 1000. Differences between the FMLUs and the OUs reduced when this restriction was applied to the cohort (Table 3).

The Danish study found no difference in perinatal morbidity between infants of low-risk women who intended to birth in a FMLU compared to OUs (Table 4). There was one neonatal death in the total cohort which was due to a severe diaphragmatic hernia not detected on ultrasound screening.

The New Zealand study was not powered to detect differences between place of birth and perinatal mortality but did report on Apgars of less than 7 at five minutes and admission to NICU (Table 5). For women with low-risk pregnancies who planned to give birth in a tertiary unit the adjusted risk ratio of having a baby with an Apgar of less than 7 at five minutes was 1.58 (CI 95% 0.95- 2.61) times that of a woman with a low- risk pregnancy planning to birth in a FMLU. The risk of admission to a NICU for a baby of a woman with a low-risk pregnancy who planned to birth in a tertiary unit was 1.78 (CI 95% 1.31-2.42) times that of a woman planning a FMLU.

Transfer to an obstetric unit

Both the Birthplace UK study and the Danish study reported on transfer rates between free standing midwifery led units and obstetric units (Table 6). There were variations in the rate of transfer between the studies but similarities in transfer rates for nulliparous women. The New Zealand study did not report data on transfers.


This literature review has been structured in a systematic way so that findings which are central to the issues could be rigorously and systematically mapped out and critically appraised. A clearly identified question and search strategy was utilised. Differing quantitative research designs were included as it was considered that randomised control trials may not be feasible for this research issue. Two well designed prospective cohort studies and an observational study have been included in this review. Well designed cohort studies can provide several advantages. They can demonstrate causal associations, provide direct calculation of the incidence of risk and allow different and sometimes uncommon outcomes to be assessed.

The aim of this review was to compare and critically appraise published studies on FMLU's to determine the evidence that may be transferrable to the New Zealand maternity context. The three studies identified by this review have demonstrated similar and consistent outcomes. This review has appraised data on a total of 14,998 women and their babies, who planned to birth in a FMLU, of which 19% (n=2,877) were from the New Zealand maternity context. It was found that when low-risk women planned to birth in a FMLU there was less augmentation of labour and increased rates of spontaneous vaginal birth when compared to women who gave birth in an OU. There was a concomitant reduction in the rates of instrumental birth, caesarean section and episiotomy when compared with outcomes for low-risk women who planned to birth in an OU. Neonatal health appeared to benefit with no differences in mortality rates but higher Apgar scores and lower rates of admission to a neonatal unit for babies when birth was planned in FMLU. Thus there would appear to be substantial health and safety benefits for low-risk women and their babies who plan to birth in FMLU.

The New Zealand context

Can the results of this review be generalised to the New Zealand maternity context? There are clearly some similarities and differences between the New Zealand maternity system and those of Denmark and England. In New Zealand women are universally able to access continuity of care from a LMC midwife or her backup (Ministry of Health, 2011a). The woman meets the midwife LMC when first pregnant and all antenatal care is provided in the community by the midwife. This enables the development of a relationship with the woman and her family/whanau which includes intrapartum care planning and provision. Additionally, when a woman requires transfer to an obstetric unit the midwife will often accompany the woman and continue to provide care. Having a midwife who knows the woman may enhance and support increased safety because the midwife has an in-depth knowledge of the woman, her obstetric, medical and pregnancy history which can be shared with other health professionals when required. This model of care enhances satisfaction with maternity services. The recently published consumer satisfaction survey indicates that LMC midwifery care achieves the highest level of satisfaction (Ministry of Health, 2012a).

This model of care is not universally available in either Denmark or England although continuity of care is considered important in England with the following commitment statement made in 2007 by the Department of Health (Department of Health, 2007).

... every woman will be supported by a midwife she knows and trusts throughout her pregnancy and after birth (p5).

The maternity service in the UK is striving to support continuity of midwifery care for the antenatal and postnatal periods but universal access to full continuity involving the provision of intrapartum care is not available except for women planning a homebirth (National Childbirth Trust, 2008). In Denmark maternity care is more fragmented with provision of antenatal and postnatal care in the community by midwives with hospital midwives providing intrapartum care. The free standing midwifery units were considered innovative for the Danish maternity situation and were closed during the study period by the Danish National Board of Health owing to concerns that a new model of care had been introduced without sufficient evaluation (Overgaard, et al., 2011). Yet the move to and centralisation of births to obstetric units has occurred with little evaluation in many countries.

Although the model of maternity care is different in each country midwifery care is the key determinate of the differences between the obstetric units and midwifery led units. Midwifery led care is often considered a 'social' model of care and characterized by a philosophy that views birth as a physiological and social process (National Childbirth Trust, 2011; New Zealand College of Midwives, 2008; Wagner, 1994). Care provision within midwifery led units will often follow this philosophy of care with a focus on emotional and psychological support as well as physical care (National Childbirth Trust, 2008; New Zealand College of Midwives, 2008; Smythe, Payne, Wilson, & Wynward, 2009). FMLUs offer welcoming family friendly environments which support the woman and her family by providing a range of options such as different positions for labour, alternative non-pharmacological approaches to help women cope with pain and positive reinforcement (National Childbirth Trust, 2008; Smythe, et al., 2009). Women reported more satisfaction with FMLUs in the UK stating that they had a greater sense of freedom, more privacy and autonomy and were more likely to be able to walk around (National Childbirth Trust, 2008). They were also more able to control who came into the room as well as control the lighting, set up and temperature of their environment. This philosophy of woman-centred care is the key similarity in the care provision in FMLU's.

There has been a move within the United Kingdom to increase choice for women by providing increased access to midwifery led care and more availability of midwifery led birthing facilities (Department of Health, 2007). In 2007 only 2% of women in England gave birth in a FMLU (Birthplace in England Collaborative Group, 2011). The proportion of trusts providing FMLU in the UK has subsequently increased from 18% in 2007 to 24% in 2010. In a recent survey of 121 women in the UK 62.8% of respondents reported that they would choose to have their baby in a FMLU because of the homely environment, accessibility and ability to use water for labour (Rogers, Harman, & Selo-Ojeme, 2011). The main reason given among those who would prefer to birth in an obstetric unit were concerns about safety. The results of the Birthplace in England research are being used to provide women with evidence to facilitate their decision making about place of birth (Birthplace in England Collaborative Group, 2011).

An issue that has been highlighted by this review is the differences in transfer rates between England (21%) and Denmark (14.8%). It is unclear why this is but these differences could be caused by a variety of influences such as differences in labour care and management, distance from an obstetric unit or confidence levels of the midwives or mothers. Both studies that reported this outcome measure found a higher rate of transfer for nulliparous women. The level of transfer in New Zealand was not reported in the New Zealand study that was used but overall transfer rates are reported in the NZCOM/ MMPO annual reports. The report for 2010 found that approximately 16% of women transfer from a primary unit during labour (New Zealand College of Midwives & Midwifery and Maternity Provider Organisation, 2011). Higher numbers of multiparous women (14.6%) give birth in a primary unit than nulliparous women (9.5%).

New Zealand has a set of referral guidelines recently updated, which outline the criteria for referral to secondary/tertiary services along with process maps that provide pathways to support transfer during intrapartum care (Ministry of Health, 2011a). These guidelines are designed to support national consistency whilst also ensuring that the woman, her baby and family/whanau remain at the centre of any discussions and decision-making. These long standing national guidelines may have an influence on the rates of transfer as they are used nationally to support decisions about place of birth and transfers from primary to secondary/tertiary services. Transfer rates may also be influenced by geography/rurality.

The results of this review indicate benefits for both maternal and neonatal health when low- risk women plan to give birth in a FMLU. We would argue that the results of this review are transferrable to the New Zealand context.

Midwives need to discuss and share these findings with women and their families/whanau. Information resources need to be designed that support decision making and choice for women and which take into account the outcomes for each birth place setting.


More research is needed in New Zealand exploring the choices of place of birth. Who and what influence women's decision making about birth place setting? There is also a need for a specific prospective study of maternal and perinatal outcomes (as per the Birthplace in England study) for planned place of birth for all settings and which is powered to detect differences in neonatal outcomes. This will provide more specific evidence for the New Zealand maternity sector and provide detailed information on outcomes, transfer rates and the safety of primary units for low risk women.


There is now strong and consistent evidence that women with low- risk pregnancies who plan to birth in a FMLU are more likely to have a normal birth, have less intervention during labour and experience low levels of perinatal mortality and morbidity. Giving birth in an obstetric unit increases the likelihood of intervention during labour and subsequent morbidities for the low- risk mother without any improvement in perinatal outcomes. The similarities in outcomes of the included studies in this review add to the midwifery knowledge base and provide important evidence indicating that the optimal place of birth for low-risk women is in a FMLU. These units provide low key individualised care for women in a calm and comfortable environment.


Begley, C., Devane, D., Clarje, M., McCann, C., Hughes, P., Reilly, M., et al. (2011). Comparison of midwife-led and consultant-led care of healthy women at low risk of childbirth complications in the Republic of Ireland: a randomised trial. BMC Pregnancy and Childbirth, 11(85).

Bernitz, S., Rolland, R., Blix, E., Jacobson, M., Sjoborg, K., & Oian, P. (2011). Is the operative delivery rate in low-risk women dependant on the level of birth care? A randomised controlled trial. BJOG An International Journal of Obstetrics and Gynaecology, 118(11), 1357-1364.

Birthplace in England Collaborative Group (2011). Perinatal and maternal outcomes by planned place of birth for healthy women with low risk pregnancies: the Birthplace in England national prospective cohort study. BMJ, 343d7400. doi:10.1136/bmj.d7400

Canterbury District Health Board (2012). Improving the Maternity Journey For Women in Canterbury. Christchurch: Canterbury District Health Board.

Cheung, N., Mander, R., Wang, X., Fu, W., Zhou, H., & Zhang, L. (2011). Clinical outcomes of the first midwife-led normal birth unit in China: a retrospective cohort study. Midwifery, 27, 582-587.

Davis, D., Baddock, S., Pairman, S., Hunter, M., Benn, C., Wilson, D., et al. (2011). Planned Place of Birth in New Zealand: Does it Affect Mode of Birth and Intervention Rates Among Low-Risk Women? Birth, 38, 111-119.

Department of Health (2007). Maternity matters: choice, access and continuity of care in a safe service. United Kindom: Department of Health.

Eide, B., Nilsen, A., & Rasmussen, S. (2009). Births in two different delivery units in the same clinic--A prospective study of healthy primiparous women. BMC Pregnancy and Childbirth, 5(25).

Henderson, J., & Petrou, S. (2008). Economic Implications of Home Briths and Birth Centers: A Structured Review. Birth, 35(2), 136-146.

Hendry, C. (2009). Report on mapping the rural midwifery workforce in New Zealand for 2008. New Zealand College of Midwives Journal, 41(12-19).

Houghton, G., Bedwell, C., Forsey, M., Baker, L., & Lavender, T. (2008). Factors influencing choice in birth place--an exploration of the views of women and their partners and professionals. Evidence Based Midwifery, 6(2), 59-64.

Laws, P., Tracy, S., & Sullivan, E. (2010). Perinatal outcomes of women intending to give birth in birth centers in Australia. Birth, 37(1), 28-36.

Maassen, M., Hendrix, M., Vugt, H. V., Veersema, S., Smits, F., & Nijhuis, J. (2008). Operative deliveries in low-risk pregnancies in the Netherlands: Primary verses secondary care. Birth, 35(4), 277-282.

McCourt, C., Rance, S., Rayment, J., & Sandall, J. (2011). Birthplace qualitative organisational case studies: how maternity care systems may affect the provision of care in different birth settings. Birthplace in England research programme. Final report part 6: NIHR Service Delivery and Organisation programme.

Ministry of Health (2011a). Guidelines for Consultation with Obsetric and Related Medical Services (Referral Guidelines). Wellington: Ministry of Health.

Ministry of Health (2011b). New Zealand Maternity Standards: A set of standards to guide the planning, funding and monitoring of maternity services by the Ministry of Health and District Health Boards.

Ministry of Health (2012a). New Zealand Maternity Clinical Indicators 2009. Wellington: Ministry of Health.

Ministry of Health (2012b). Maternity Consumer Surveys 2011. Wellington: Ministry of Health.

National Childbirth Trust. Your care through pregnancy, labour and birth Retrieved 5th May 2012, from

National Childbirth Trust (2008). NCT Policy Briefing: Midwife-led units, community maternity units and birth centres. Retrieved 14th March 2012: default/files/related documents/MS2%20Midwife-led%20units.pdf

New Zealand College of Midwives (2008). Midwives Handbook for Practice. Christchurch: New Zealand College of Midwives.

New Zealand College of Midwives, & Midwifery and Maternity Providers Organisation (2011). New Zealand College of Midwives Report on MMPO-Midwives Care Activities and Outcomes 2010. Christchurch: New Zealand College of Midwives, Midwifery and Maternity Providers Organisation,.

Overgaard, C., A Moller, Fenger-Gron, M., Knudsen, L., & Sandall, J. (2011). Freestanding midwifery unit versus obstetric unit: a matched cohort study of outcomes in low-risk women. BMJ Open, 2(e000262). doi:10.1136/bmjopen-2011-000262

Pitchforth, E., Watson, V., Tucker, J., Ryan, M., Teijlingen, E. v., Farmer, J., et al. (2008). Models of intrapartum care and women's trade-offs in remote and rural Scotland: a mixedmethods study. British Journal of Obstetrics and Gynaecology, 115(5), 560-569.

Redshaw, M., Rowe, R., Schroeder, L., Puddicombe, D., Macfarlane, A., Newburn, M., et al. (2011). Mapping maternity care: the configuration of maternity care in England: Birthplace in England research programme. Final report part 3. NIHR Service Delivery and Organisation programme.

Rogers, C., Harman, J., & Selo-Ojeme, D. (2011). Perceptions of birth in a stand-alone centre compared to other options. British Journal of Midwifery, 19(4).

Skinner, J., & Lennox, S. (2006). Promoting normal birth: a case for birth centres. New Zealand College of Midwives Journal, 34, 15-18.

Smythe, L., Payne, D., Wilson, S., & Wynward, S. (2009). Warkworth Birthing Centre: exemplifying the future. New Zealand College of Midwives Journal, 41, 7-11.

Stewart, M., McCandish, R., Henderson, J., & Brocklehurst, P. (2004). Report of a structured review of birth centre outcomes. United Kingdom: Maternity Research Group of the National Service Framework for Children, Young People and Maternity Services.

Symon, A., Winter, C., Inkster, M., & Donnan, P. (2009). Outcomes for births booked under an independant midwife and births in NHS maternity units: matched comparison study. BMJ, 338(b2060).

Tracy, S., Caplice, S., Laws, P., Wang, Y., Tracy, M., & Sullivan, E. (2007). Birth centers in Australia: A national population-based study of perinatal mortality associated with giving birth in a birth center. Birth, 34, 194-201.

Wagner, M. (1994). Pursuing the Birth Machine. Australia: ACE Graphics.

Walsh, D., & Downe, S. (2004). Outcomes of Free-Standing, Midwife-Led Birth Centers: A Structured Review. Birth, 31(3), 222-229.

Conflict of Interest: Lesley Dixon was also a co-author for the paper: Planned Place of Birth in New Zealand: Does it Affect Mode of Birth and Intervention Rates Among Low-Risk Women?

Accepted for publication May 2012


* Lesley Dixon, PhD, MMid, BA (Hons), RM

Midwifery Advisor

New Zealand College of Midwives


* Gail Prileszky, BSc (Hons) RM

Research Project Midwife

New Zealand College of Midwives

* Karen Guilliland, MA, RM, RGON, ADN, MNZM


New Zealand College of Midwives

* Chris Hendry, DMid, MPH, RM, RN

Executive Officer

Midwifery and Maternity Provider Organisation

* Suzanne Miller, MMid, RM


Otago Polytechnic School of Midwifery

* Jacqui Anderson, MMid, RM, RGON

LMC midwife

Senior Midwifery Lecturer and

Co Head of Midwifery

Canterbury Polytechnic Institute of Technology
Table 1 Excluded studies

Authors       Study design    Sample size      Inclusion / exclusion
and country                                    criteria

Begley et     Randomised      1653 women       Comprehensive
al 2011       trial           randomised       exclusion criteria to
Republic of   intention to    1101 to MLU      determine risk factors
Ireland       treat           (Midwife Led     including demographic
              analysis        Unit), 552 to    characteristics,
                              CLU              medical,
                              (consultant      gynaecological and
                              led unit         obstetric history

Bernitz et    Randomised      1111 low risk    Low risk at onset of
al 2011       controlled      women            labour defined by
Norway        trial           randomised to    inclusion criteria
                              special unit,    matching selection
                              normal unit or   criteria at the MLU
                              midwife led

Cheung et     Retrospective   226 women        Term women with
al 2011       cohort study    accessing MNBU   singleton cephalic
China         plus            matched with     pregnancy, no
              questionnaire   226 controls     complications of
              survey          accessing        pregnancy or
                              standard care    significant medical
                                               problem and a normal
                                               CTG trace were

Eide et al    Prospective     252 women in     Low risk women who met
2009 Norway   non             MLW and 201      the criteria for
              randomised      women in CDW     delivery in the MLW
              observational   (Conventional    (Midwife Led Ward) who
              study           Delivery         did not have a
                              Ward).           preference were
                              Allocation was   allocated to either
                              alternated       MLW or CDW. Women
                              between MLW      requesting epidural
                              and CDW          were excluded

Laws et al    Retrospective   822,955          Women aged 20-34 yrs,
2010          analysis of     mothers and      who had a singleton
Australia     population      836,919          baby of >2500g. Women
              database        babies. 2.7%     who had hypertension
                              (22,222) of      or diabetes (pre-
                              these women      existing or
                              intended to      gestational) were
                              birth in a       excluded
                              birth centre

Maassen et    Retrospective   107,667 low      Inclusion and
al 2008 The   analysis of     risk women;      exclusion criteria as
Netherlands   national        87,817 in        assessment of risk
              database        primary care     clearly defined
                              with midwife,
                              19,850 in
                              secondary care

Symon et al   Retrospective   8676 women;      All women cared for by
2009 UK       matched         1462 cared for   independent midwives in
              cohort          by independent   UK between 2002-2005
              analysis        midwives (IMA)
                              matched with
                              7214 cared for
                              by NHS
                              midwives (NHS)

Tracy et al   Retrospective   1,001,249        All women who gave
2007          population      women of whom    birth in Australia
Australia     based study     21,800 gave      between 1999-2002.
                              birth in a       Multiparous and
                              birth centre     primiparous women
                                               analysed separately

Authors       Outcome measures       Main findings          Reason for
and country                                                 exclusion

Begley et     9 key maternal and     No significant         Alongside
al 2011       neonatal outcomes      difference in seven    midwifery
Republic of   including caesarean    key maternal and       led unit
Ireland       birth, induction,      neonatal outcomes.
              episiotomy,            MLU women
              instrumental birth,    significantly less
              Apgar score<8, PPH,    likely to have
              breastfeeding          continuous EFM and
              initiation,            augmentation of
              continuous EFM,        labour
              augmentation of

Bernitz et    Primary outcome was    No significant         Alongside
al 2011       operative delivery     differences in         midwifery
Norway        rate. Secondary        operative delivery     led unit
              outcomes were          rates, PPH,
              augmentation, pain     sphincter injuries
              relief, PPH,           or neonatal
              sphincter injuries,    outcomes.
              intrapartum            Significantly less
              transfer, Apgar        augmentation,
              score<7, metabolic     epidural analgesia
              acidosis and           in MLU.
              transfer to NICU

Cheung et     Mode of birth and      Vaginal birth rate     Alongside
al 2011       model of care          of 87.6% in MNBU       midwifery
China                                (Midwife-led Normal    led unit
                                     Birth Unit) compared
                                     to 58.8% in standard
                                     care unit

Eide et al    Maternal               No significant         Alongside
2009 Norway   intervention rates,    difference between     midwifery
              caesarean section      emergency caesarean    led unit
              and instrumental       and instrumental
              birth rates.           rates. Higher
                                     incidence of
                                     episiotomy epidural
                                     analgesia, pudendal
                                     nerve block and
                                     nitrous oxide in the
                                     CDW. Higher
                                     incidence of opiate
                                     and nonpharmacological
                                     relief in the MLW

Laws et al    Maternal and           Lower rates of         Alongside
2010          neonatal outcomes      intervention and       midwifery
Australia     including method of    adverse perinatal      led unit
              birth, onset of        outcomes for women
              labour, episiotomy,    in birth centres. No
              third fourth degree    significant
              tear, Apgar score,     difference in
              admission to NICU      perinatal mortality
                                     for low risk women
                                     at term.

Maassen et    Primary outcome:       Significantly lower    Comparison
al 2008 The   rate of operative      rates of operative     of model
Netherlands   deliveries             vaginal birth,         of care
                                     caesarean section in   (midwife
                                     primary care group.    verses
                                     Significantly lower    obstetri-
                                     rates                  cian)
                                     of primiparous
                                     caesarean section in   not place
                                     primary care group.    of birth
                                     Significantly higher
                                     rates of spontaneous
                                     vaginal birth for
                                     multiparous and
                                     primiparous women in
                                     primary care group

Symon et al   Primary outcome:       IMA mothers were       Comparison
2009 UK       rate of unassisted     significantly more     of model
              vertex delivery.       likely to have an      of care
              Secondary outcomes;    unassisted vertex      not place
              live birth,            birth but were also    of birth
              perinatal death,       more likely to
              onset of labour,       experience a
              gestation, use of      stillbirth or
              pharmacological        neonatal death.
              analgesia, duration    Exclusion of high
              of labour, apgar       risk pregnancies
              scores, admission to   made this a non
              NICU and infant        significant
              feeding                difference. The low
                                     risk IMA perinatal
                                     mortality rate is
                                     comparable to other
                                     low risk studies.
                                     IMA mothers were
                                     more likely to have
                                     a spontaneous onset
                                     of labour and use
                                     less pharmacological
                                     pain relief

Tracy et al   Perinatal outcomes     Perinatal death rate   Alongside
2007          including stillbirth   was significantly      midwifery
Australia     and perinatal death    lower in birth         led unit
                                     centres than in
                                     irrespective of

Table 2 Included studies

Authors and     Study design       Inclusion /        Outcome measures
country         and sample size    exclusion

Birthplace      Prospective        Singleton          Composite
in England      cohort study       pregnancy at       primary outcome
Collabora-      64538 women        term included      measure of
tive Group      Cohorts were by    planned            perinatal
2011 UK         planned place of   caesarean          mortality and
                birth; home,       section or         morbidity.
                standalone MLU,    caesarean          Secondary
                alongside MLU,     section prior to   outcomes were
                stratified         labour were        maternal
                sample of          excluded           morbidities,
                obstetric units                       interventions
                                                      and mode of

Overgaard et    Retrospective      All women who      Perinatal and
al 2011         matched cohort     were admitted to   maternal
Denmark         study 839 low      FMLU in labour     morbidity and
                risk women         between 2004 and   interventions
                intending FMLU     2008. Controls
                birth matched      were matched to
                with 839 low       individual
                risk women         obstetric and
                intending          social
                obstetric unit     characteristics

Davis et al     Retrospective      Low risk women     Mode of birth,
2011 New        cohort study       defined by range   intrapartum
Zealand         16453 Low risk     of medical and     interventions,
                women              obstetric          neonatal
                                   criteria           outcomes

Authors and     Main findings          Comments

Birthplace      No significant         Sub analysis was
in England      differences in         conducted to
Collabora-      primary outcome for    differentiate
tive Group      any non obstetric      between low risk and
2011 UK         setting compared       higher risk
                with obstetric         pregnancies
                units. Nulliparous
                women who planned a
                home birth had
                higher odds of
                primary outcome

Overgaard et    No differences in      Four units were
al 2011         perinatal morbidity.   compared two FMLU
Denmark         Significantly          and two obstetric
                reduced incidences     units
                of maternal
                morbidity, birth
                interventions and
                increased likelihood
                of spontaneous
                normal birth for
                women intending FMLU

Davis et al     Higher risk of         Data collected from
2011 New        caesarean section,     MMPO database
Zealand         assisted modes of
                birth and
                intervention for
                women planning to
                birth in secondary
                or tertiary unit
                plus higher risk of
                neonatal admission
                to NICU

Table 3 Maternal and Neonatal Outcomes for the Birthplace in
England study

Birthplace in England Collaborative group 2011

                                   FMLU                CI 99%

Mode of birth                      N =11280     %

Spontaneous vaginal birth          10,150       90.7   (89.1-92.0)
Ventouse birth                     321          2.7    (2.0-3.5)
Forceps birth                      365          2.9    (2.3-3.7)
Intrapartum caesarean section      405          3.5    (2.8-4.2)

Interventions during labour

Syntocinon Augmentation            878          7.1    (6.0-8.5)
Epidural                           1251         10.6   (9.1-12.3)
Immersion in water                 5253         45.7   (35.6-56.3)
General anaesthesia                61           0.5    (0-3-0.8)
No active management of
  3rd stage                        2568         22.1   (15.8-30.0)

Maternal morbidity

Third of fourth degree tears       259          2.3    (1.9-2.9)
Episiotomy                         995          8.6    (7.3-10.1)

Neonatal mortality &               N = 11,199          Per 1000
  morbidity composite                                  (95% CI)
Overall cohort                     41                  3.5 (2.5-4.9)
Without complicating conditions    N= 10,571           N=15676
  at start of labour               35                  3.2 (2.3-4.6)

                                   OU                CI 99%

Mode of birth                      N =19688   %

Spontaneous vaginal birth          14,645     73.8   (71.1-76.4)
Ventouse birth                     1535       8.1    (6.4-10.1)
Forceps birth                      1307       6.8    (5.4-8.4)
Intrapartum caesarean section      2158       11.1   (9.5-13.0)

Interventions during labour

Syntocinon Augmentation            4549       23.5   (21.1--26.2)
Epidural                           5817       30.7   (27.5-34.2)
Immersion in water                 1836       9.1    (6.4-12.6)
General anaesthesia                285        1.5    (1.1-1.8)
No active management of
  3rd stage                        1188       6.1    (4.6-8.1)

Maternal morbidity

Third of fourth degree tears       625        3.2    (2.7-3.7)
Episiotomy                         3780       19.3   (17.4-21.4)

Neonatal mortality &               N=19551           Per 1000
  morbidity composite                                (95% CI)
Overall cohort                     81                4.4 (3.2-5.9)
Without complicating conditions
  at start of labour               48                3.1 (2.2-4.2)

* neonatal composite outcomes were: stillbirth after start of labour
care, early neonatal death, neonatal encephalopathy, meconium
aspiration syndrome, brachial plexus injury, fractured humerus or

Table 4 Maternal and neonatal outcomes for the Danish study

Danish Study                     FMLU            OU
(Overgaard et al., 2011)         n = 839 women   n = 839 women

Mode of birth                    N     %         N     %

Spontaneous vaginal birth        796   94.9      751   89.5
Instrumental birth               25    3.0       61    7.8
Caesarean section                19    2.3       34    04.0

Interventions during labour

Augmentation                     69    8.2       154   18.6
Epidural (pain relief)           35    4.2       85    10.3
Water tub for pain relief        269   32.1      197   23.5

Maternal morbidity

Third and fourth degree tears    19    2.3       24    2.9
PPH > 500 mls                    29    3.5       68    8.1
PPH > 1000mls                    11    1.3       14    1.7

Perinatal morbidity

Neonatal asphyxia                27    3.2       41    4.9
Apgar score <7 at 5 minutes      5     0.6       5     0.6
Admission to NICU                28    3.3       42    5.0

Danish Study                     RR 95%             P value
(Overgaard et al., 2011)

Mode of birth

Spontaneous vaginal birth        1.06 (1.03-1.09)   0.000
Instrumental birth               0.4 (0.3-0.6)      0.000
Caesarean section                0.6 (0.3-09)       0.04

Interventions during labour

Augmentation                     0.5 (0.3-0.6)      0.000
Epidural (pain relief)           0.4 (0.3-0.6)      0.000
Water tub for pain relief        1.4 (1.2- 1.6)     0.0001

Maternal morbidity

Third and fourth degree tears    0.8 (0.4-1.4)      0.5224
PPH > 500 mls                    0.4 (0.3-0.7)      0.0001
PPH > 1000mls                    0.8 (0.4-1.7)      0.6900

Perinatal morbidity

Neonatal asphyxia                0.7 (0.4-1.1)      0.1143
Apgar score <7 at 5 minutes      1.0 (0.3-3.4)      1.0000
Admission to NICU                0.7 (0.4-1.1)      0.1143

Table 5 Maternal and Neonatal outcomes for NZ planned place of
birth study

Planned place of birth in           Primary Unit     Secondary unit
New Zealand (Davis, et al 2011)     (FMLU)           (OU) n = 7,353
                                    n = 2873

Mode of birth                       N        %       N        %

Spontaneous vaginal birth           2,722    94.7    6,216    84.5
Ventouse birth                      34       1.1     352      4.8
Forceps birth                       24       0.9     161      2.2
Caesarean section                   91       3.2     622      8.5

Interventions during labour         Ref              Adjusted RR
                                                     (95% CI)

Augmentation                        1.0              1.91 (1.73-2.10)
Artificial Rupture of Membranes     1.0              1.49 (1.34-1.65)
Pharmacological pain management     1.0              1.49 (1.36-1.64)

Maternal morbidity

Perineal trauma-level not stated    1.0              0.83 (0.76-0.91)
Episiotomy                          1.0              1.88 (1.54-2.30)
PPH >1000mls                        1.0              1.20 (0.80-1.81)

Neonatal outcomes

Apgar score <7 at 5 minutes         1.0              1.39 (0.87-2.22)
Admission to NICU                   1.0              1.40 (1.05-1.87)

Planned place of birth in           Tertiary Unit       P value for
New Zealand (Davis, et al 2011)     (OU) n = 4,095      tertiary
Mode of birth                       N       %

Spontaneous vaginal birth           2,979   72.7
Ventouse birth                      304     7.4
Forceps birth                       201     4.9
Caesarean section                   610     14.9

Interventions during labour

Augmentation                        1.87 (1.68-2.08)    0.001
Artificial Rupture of Membranes     1.51 (1.35-1.70)    0.001
Pharmacological pain management     1.64 (1.47-1.82)    0.001

Maternal morbidity

Perineal trauma-level not stated    0.91 (0.82-1.02)    0.098
Episiotomy                          2.91 (2.37-3.57)    0.001
PPH >1000mls                        1.39 (0.90-2.16)    0.138

Neonatal outcomes

Apgar score <7 at 5 minutes         1.58 (0.95-2.61)    0.077
Admission to NICU                   1.78 (1.31-2.42)    0.001

* Relative risks adjusted for age, parity, ethnicity & smoking

Table 6 Transfer rates for Danish and Birth in England

Transfers from freestanding    Birthplace    Danish Study
midwifery led unit             in England

Overall transfer rates         21.9%         14.8%
Before the birth               16.5%         11.5%
After the birth                4.8%          3.2%
Nulliparous women              36.3%         36.7%
Multiparous women              9.4%          7.2%
COPYRIGHT 2012 New Zealand College of Midwives
No portion of this article can be reproduced without the express written permission from the copyright holder.
Copyright 2012 Gale, Cengage Learning. All rights reserved.

Article Details
Printer friendly Cite/link Email Feedback
Title Annotation:PRACTICE ISSUE
Author:Dixon, Lesley; Prileszky, Gail; Guilliland, Karen; Hendry, Chris; Miller, Suzanne; Anderson, Jacqui
Publication:New Zealand College of Midwives Journal
Article Type:Report
Geographic Code:8NEWZ
Date:Jun 1, 2012
Previous Article:Discerning which qualitative approach fits best.
Next Article:Women's experience of the abdominal palpation in pregnancy; a glimpse into the philosophical and midwifery literature.

Terms of use | Privacy policy | Copyright © 2019 Farlex, Inc. | Feedback | For webmasters