Induction of Labour Snapshot Audit
Source: data.gov.uk (2025-12-17)

NMPA Induction of Labour Snapshot Audit. Induction of Labour Snapshot Audit Based on births in NHS maternity services in England, Scotland and Wales during 2023

Induction of Labour Snapshot Audit
Based on births in NHS maternity services in England, Scotland and Wales 
during 2023
Published November 2025

Introduction
Induction of labour (IOL) is the process of artificially starting labour by the softening 
and opening of the cervix and/or breaking the amniotic membranes.
This report uses data from births that occurred in NHS maternity services in 2023 to analyse the 
characteristics and outcomes of women and birthing people undergoing IOL in Great Britain. The 
report identifies factors that may influence mode of birth and 5-minute Apgar score following 
induction, and analyses variation in one of the most frequently used interventions to bring about 
labour and childbirth.
Rates of IOL are rising across Great Britain and many high-income countries. NHS England have reported an 
increase in rates from 22% in 2011/12 to 33% in 2023/24. The National Maternity and Perinatal Audit (NMPA) 
have identified not only an increase in IOL rates but also a pattern of wide variation in rates between maternity 
care providers that persists across annual clinical reports between 2015–2019. In 2015/16, the average IOL rate 
was 29% and trust- and board-level rates varied from 20% to 46%. By 2023, the average rate had risen to 34% 
(trust- and board-level variation was 12–47%). This was despite adjusting for population-level factors such as 
maternal age, gestational age, parity, and previous caesarean birth. Such data patterns may not be explained 
by chance alone but may be influenced by local policies and practice, application of national guidance, and 
geographical location and proximity to maternity services for some women and birthing people. National 
guidelines that may contribute to decision-making, such as those published by National Institute for Health and 
Care Excellence (NICE) and NHS England’s Saving Babies Lives Care Bundle version 3, offer guidance on where 
and when to offer an IOL.
The decision to opt for an IOL may be challenging for some women and birthing people. Evidence from a 
systematic review, meta-analysis and randomised trial demonstrates that IOL is associated with a decreased 
likelihood of a caesarean birth, and does not increase the chance of giving birth with the use of instruments. 
IOL may be more painful than a spontaneous labour, but does not restrict pain relief options. The induction 
process may take longer than spontaneous labour and may require additional interventions including multiple 
vaginal examinations. While some women and birthing people undergoing IOL may describe the experience as 
a positive one, others may report feelings of disappointment and dissatisfaction. These factors among others, 
may contribute to the decision-making process when a clinician offers an IOL. Some women and birthing 
people may choose instead to await spontaneous labour, or opt for a caesarean birth. Healthcare professionals 
supporting women and birthing people in their decision-making must ensure the information provided is clear 
and unbiased, and explains the options available based on each individual’s personal circumstances. 
Analysing data for those who experienced an induction of labour leads to a highly selective population, 
meaning this report is reflective of current practices and maternal preferences at the time the data was 
collected. As practices and preferences evolve over time, it can be expected the population experiencing an 
IOL may also change.
2
Introduction
2
How to use this report
3
Results at a glance
4
Key messages and 
Recommendations
5
Results
6
Research priorities
12
Contents
•	
cervical balloon 
•	
hormone pessaries, tablets and gels 
•	
cervical dilating rods 
•	
oxytocin infusion 
•	
artificial rupture of the amniotic membranes 
About Induction Of Labour
Induction of labour can be performed using one or 
more of the following methods:
Further information about 
induction of labour can be found 
at NHS Inducing Labour

This report presents the key findings and recom­
mendations of the snapshot audit. The following 
additional supporting documents can be found on 
our website:
» A glossary explaining the terminology and 
abbreviations used in our reports
» A Methods and Results document outlining 
how the analysis was carried out, as well as 
summary results tables and supplementary results
» Trust/board-level data tables
» A Lay Summary
» A line-of-sight table describing the evidence 
base for the recommendations in this report
» A video guide to interpreting funnel plots
How to use this report
3
This snapshot audit focuses on singleton pregnancies undergoing IOL where the labour is expected to 
result in the birth of a live baby. For a very small number of pregnancies, IOL may be recommended after 
confirming that an unborn baby’s heartbeat has stopped. Under these circumstances, the rationale for 
offering an IOL is different (i.e., preventing infection, psychological welfare) and therefore, these births 
are not included in this report.
This report expands upon findings from the NMPA 2023 State of the Nation report using the same 
dataset. The IOL measure reported in the NMPA annual clinical report results includes singleton 
births between 37+0 and 42+6 weeks gestation, this report includes births from 24+0 weeks. General 
information about the development of this dataset can be found in the 2023 annual clinical report 
Methods and Measures Technical Specification documents.
About the data
Case-mix adjustment
Variation in care processes and outcomes can be used to highlight differences between trusts/boards. 
Factors such as clinical and demographic characteristics of women and birthing people can affect both the 
demands placed on the maternity service and the outcomes of care. 
In order to make meaningful and fair comparisons between trusts/boards with different patient 
populations, we carry out a statistical adjustment called ‘case-mix adjustment’. This process aims to 
take into account any factors which may have an effect on the results and are outwith the control of the 
maternity service, for example maternal age or previous obstetric history. 
More information about case-mix adjustment can be found in the 2023 annual clinical report Methods 
and Measures Technical Specification documents online.


Results at a glance
The National Maternity and Perinatal Audit (NMPA) uses information collected routinely as part of 
NHS maternity care, combined with information collected when women and birthing people and their
babies are admitted to hospital, to report on a range of care process and outcome measures.
 
Summarised here are results for the 173 074 women and birthing people who underwent an induction of labour (IOL) 
in the NHS in 2023. Details of the methods, summary results table and supplementary results can be found in the 
Methods and Results document.
4
One in three women and birthing people 
had an induction of labour
Of those who were induced, one in 
three gave birth by caesarean
←
32%
←
46%
16%
IOL rates varied between trusts/boards
IOL
Caesarean Birth
Caesarean birth rates following IOL varied
 between trusts/boards
Of the babies born 
following IOL, 16 in 1000 
were assigned an Apgar 
score of less than 7 at 5 
minutes
How maternal characteristics may influence 
outcomes are displayed as graphs for mode of 
birth (click here to view) and 5-minute Apgar 
score (click here to view). 
The characteristics include:
•	 Maternal age
•	 Ethnic group
•	 Socioeconomic deprivation
•	 Pregnancy history
•	 Gestational age at birth
•	 Country
30%
←
←
45%
18%
SCAN ME
Find out more at:
www.maternityaudit.org.uk
15/16
17/18
2023
16/17
18/19
28.5%
29.6%
32.6%
33.5%
33.9%
NMPA annual clinical reports show an increase in rates of IOL

Key Findings and 
Recommendations
Outcomes for mothers and babies
Key Finding 1: Just under one third (32%) of women and birthing people experienced an IOL; of those, 30% gave 
birth by caesarean.
Key Finding 2: Increasing maternal age was strongly associated with increasing likelihood of giving birth by 
caesarean following IOL, and those giving birth at or after 41 weeks of gestation and from ethnic minority groups 
had a higher likelihood of giving birth by caesarean.
Key Finding 3: Babies born to women and birthing people from Black ethnic groups were more likely, and babies 
born to women and birthing people from Asian, Mixed or ‘Other’ ethnic groups were less likely, to be assigned an 
Apgar score of less than 7 at 5 minutes following IOL than babies born to white women and birthing people.
5
Trust/board variation
Key Finding 4: Unexplained variation in IOL rates extended to the mode of birth and 5-minute Apgar score experi­
enced by women and birthing people and their babies following induction of labour.
Key Finding 5: There was wide variation between trusts and boards in the proportion of caesarean births following 
IOL, 40% had rates that were higher or lower than the expected range.
Data quality and capture
Key Finding 6: IOL was recorded as unsuccessful for 6% of women and birthing people. However, this may have 
been influenced by a lack of a standardised definition, along with concerns about coding accuracy and data 
completeness.  
Key Finding 7: A number of key data items relating to IOL are not included or are incomplete in the national 
maternity datasets, these include the method, indication for and duration of induction. 
Recommendation 3: Digital teams in the Government health departments should work with maternity data 
controllers and software developers to incorporate processes and systems into the next version update of each 
dataset that support maternity care providers to record data items, such as gestational age at induction, maternal 
decision-making, the indication, method(s) and duration of induction.
Recommendation 4: The Royal College of Obstetricians and Gynaecologists (RCOG) should work collaboratively with 
stakeholders to develop a standardised definition for the diagnosis and reporting of ‘unsuccessful induction of labour’. 
Recommendation 2: Maternity care commissioners should undertake a structured review to identify the drivers of 
practice variation in IOL care within their networks, such as clinical culture, local policies and protocols and clinical 
leadership, to target a reduction in unwarranted variation in IOL care processes and outcomes.
Recommendation 1: Maternity care commissioners and maternity networks* should ensure that their constituent 
units use their local data and national data on variation in IOL practice and disparities in outcomes to inform the 
planning of service provision, and in the counselling of women and birthing people accessing their services.
*English local maternity and neonatal systems (LMNS), the Scottish Perinatal Network, and the Wales Maternity and 	
	
  Neonatal Network

NMPA maternity data contains records of 93% of births that occurred in Great Britain in 2023. This report focuses on 
data for births that took place in 114 English Trusts, 11 Scottish Boards and 5 Welsh Health Boards; capturing 533 503 
births (NMPA population), of which 173 074 experienced an induction of labour.
Table 1 shows unadjusted IOL rates and trust/board-level variation. In 2023, 32.4% of women and birthing people 
experienced IOL, with similar proportions seen across England (32.2%), Scotland (34.6%) and Wales (34.2%). These 
numbers and rates closely mirror those of the State of the Nation report, which describes singleton births undergoing 
IOL at or after 37+0 weeks of gestation; differences in the cohort construction for this report are described in the 
Methods and Results document. The extent of variation in trust/board IOL rates across Great Britain is shown in the 
relevant funnel plot produced as part of the NMPA’s annual clinical reporting.
6
Table 2 in the Methods and Results document shows characteristics of the women and birthing people who were 
induced compared to the NMPA population. Those who were induced were more likely to be aged under 30 years, 
and were more likely to give birth between 37+0–38+6 weeks of gestation or at or after 41+0 weeks. Across England, 
Scotland and Wales the proportion of those who were induced was higher for white women and birthing people, 
whereas the proportion was lower for those from all other ethnic groups. A greater proportion of those who 
were induced were giving birth for the first time and almost half were from the more deprived Index of Multiple 
Deprivation (IMD) quintiles (Q4 and Q5).  
IOL rates and 
maternal characteristics
Births (n)
Induction of 
labour (n)
IOL rate
Interquartile 
range
Trust/Board 
min 
Trust/Board 
max 
England
470 484
151 345
32.2%
28.1–37.5%
15.7%
46.4%
Scotland
42 724
14 792
34.6%
30.8–38.6%
27.5%
40.8%
Wales
20 295
6 937
34.2%
29.4–38.1%
28.4%
39.0%
Great Britain
533 503
173 074
32.4%
28.6–37.9%
15.7%
46.4%
Table 1:  Unadjusted induction of labour rates, by country 

0
5
10
15
20
25
30
35
40
45
50
0
1000
2000
3000
4000
5000
Number of IOL per trust/board
England
Scotland
Wales
% of caesarean births
Mode of birth and
5-minute Apgar score
Mode of birth
There is a chance of experiencing a caesarean birth with all pregnancies however, when opting for an induction of 
labour, most women and birthing people do so with the aim of achieving an uncomplicated vaginal birth. Once the 
induction process has started, a caesarean birth may be advised for a number of reasons including maternal request 
or where there are concerns about the health of the mother or baby. Of those who were induced, mode of birth 
was available for 173 000, 29.7% gave birth by caesarean. Unadjusted caesarean birth rates were similar for England 
(29.6%), Scotland (30.8%), and Wales (29.2%) (Table 2). The funnel plot in Figure 1 demonstrates trust/board-level 
variation in caesarean birth rates that have been adjusted for maternal age, parity, previous caesarean birth, and 
gestation at birth. Interpreting funnel plots is explained in this video.
7
IOL (n)
Caesarean birth 
following IOL (n)
Caesarean birth 
rate following IOL
Interquartile 
range
Trust/Board 
min
Trust/Board 
max
England
151 277
44 783
29.6%
25.6–34.1%
17.8%
45.2%
Scotland
14 789
4 561
30.8%
27.6–31.3%
23.4%
40.0%
Wales
6 934
2 024
29.2%
27.5–29.6%
26.2%
32.5%
Great Britain
173 000
51 368
29.7%
26.0–33.4%
17.8%
45.2%
Table 2:  Unadjusted rates of caesarean birth following IOL, by country
By chance alone, we might expect only 1 in 20 trusts/boards to have a rate beyond the inner (95%) funnel limits and 
only 1 in 500 trusts/boards to have a rate beyond the outer (99.8%) funnel limits. There was unexplained variation 
in rates of caesarean birth following IOL for approximately one third of trusts/boards. For some trusts and boards, 
around 20% of women and birthing people who were induced gave birth by a caesarean, whereas for others the rate 
was almost 40%. Explaining this pattern is challenging; factors may include (but are not limited to) local trust/board 
culture, processes and practice, differing methods used for induction, intrapartum states such as sepsis or slow labour 
progress, maternal choice or the characteristics of the individual woman or birthing person undergoing induction.
Figure 1:  Funnel plot showing case-mix adjusted caesarean birth rates following IOL

England
Scotland
Wales
34–36
37
38
39
40
41+
<20
20–24
25–29
30–34
35–39
40–44
45+
(Least Deprived) Q1
Q2
Q3
Q4
(Most Deprived) Q5
White
Black
Asian
Mixed
Other
Primiparous
Multiparous no prev' caesarean
Multiparous previous caesarean
10%
20%
30%
40%
50%
Caesarean birth following IOL
Effect of maternal characteristics 
on mode of birth
To assess how the characteristics of women and birthing people experiencing IOL may impact their likelihood of 
giving birth vaginally or giving birth by caesarean, statistical modelling has been used while controlling for other 
factors. These results are summarised in a margins plot (Figure 2). Detailed model results can be found in Table 5 in 
the Methods and Results document.
8
Figure 2: Margins plot showing the estimated likelihood of caesarean birth following IOL by maternal characteristics
Women and birthing people experiencing IOL in Scotland had a greater likelihood of giving birth by caesarean than 
those in England and Wales, although this was not statistically significant. Between 37–39 completed weeks of 
gestation there was no difference in the likelihood of a vaginal or caesarean birth, but the likelihood of a caesarean 
birth was highest for preterm births and births at or after 40 weeks of gestation. There was a strong gradient 
between increasing maternal age and increasing likelihood of a caesarean birth. Those aged 40 years or above 
were at least twice as likely to give birth by caesarean compared to those aged less than 20 years. The relationship 
between IMD and mode of birth was less strong, although there was an increase in likelihood of caesarean birth for 
women and birthing people from the most deprived quintiles (Q4 and Q5). Compared to white women and birthing 
people, those from all other ethnic groups were more likely to have a caesarean birth; the rate was significantly 
higher for those from Black and Asian ethnic groups.
Compared to those giving birth for the first time, women and birthing people who had previously given birth 
vaginally were more likely to give birth vaginally; the likelihood of a birth by caesarean was higher for those who had 
previously given birth by caesarean.
A margins plot shows the statistical model’s estimated value, or likelihood, for the outcome of interest 
for each characteristic. The point shows the model’s estimate and the bars adjacent to the point are the 
confidence interval – the shorter the bar, the greater the precision. 
The vertical line represents the GB average. 
Understanding a margins plot
Ethnic group
Parity
Gestation at birth 
(completed weeks)
Maternal age 
(years)
Index of 
Multiple 
Deprivation
Country

5-minute Apgar score
An induction of labour most frequently results in a vaginal birth. However, labours that are induced may have more 
complications and a caesarean birth may occur for a number of reasons including maternal request or concerns 
about the health of mother or baby. Depending on the condition of the baby during labour, a caesarean birth 
may be recommended as the safest mode of birth for mother and baby. It is therefore important to consider the 
outcomes for the baby, not just the mode of birth. 
The Apgar score is a tool widely used to assess the condition of a baby at time intervals following birth, typically at 
1 minute, 5 minutes and 10 minutes. A score of less than 7 at 5 minutes is suggestive of a baby requiring additional 
support. Babies born preterm (before 37 completed weeks of gestation) may have lower Apgar scores due to their 
gestation at birth.
9
IOL (n)
Apgar <7 at 5 
minutes (n)
Rate
Interquartile 
range
Trust/board 
min
Trust/board 
max
England
143 521
2 126
1.48%
0.99–1.69%
0.16%
3.97%
Scotland
14 676
371
2.53%
2.09–3.35%
1.95%
3.96%
Wales
6 936
132
1.90%
1.10–2.24%
1.03%
2.81%
Great Britain
165 133
2 629
1.59%
1.08–1.97%
0.16%
3.97%
Table 3: Unadjusted rates of Apgar score less than 7 at 5 minutes following IOL, by country
Apgar scores at 5 minutes were reviewed for 165 133 babies. Overall, 1.59% of babies were assigned an Apgar 
score of less than 7 at 5 minutes (Table 3). This rate compares to the rate of 1.45% reported in the 2023 State of the 
Nation. Average rates of an Apgar score of less than 7 at 5 minutes following IOL were higher in Scotland (2.53%) 
than in England (1.48%) and Wales (1.90%). This pattern mirrors both the 2023 State of the Nation population and 
previous annual clinical reports. The rate of babies assigned an Apgar score of less than 7 at 5 minutes following 
adjustment for maternal age, parity, previous caesarean birth, and gestation at birth was within the funnel limits for 
the majority of trusts and boards (Figure 3). 
Figure 3: Funnel plot showing case-mix adjusted rates of Apgar score of less than 7 at 5 minutes following IOL
0
1
2
3
4
5
0
1000
2000
3000
4000
5000
Number of IOL per trust/board
England
Scotland
Wales
% of babies with Apgar score <7 at 5 minutes

England
Scotland
Wales
34–36
37
38
39
40
41+
<20
20–24
25–29
30–34
35–39
40–44
45+
(Least Deprived) Q1
Q2
Q3
Q4
(Most Deprived) Q5
White
Black
Asian
Mixed
Other
Primiparous
Multiparous no prev' caesarean
Multiparous previous caesarean
0%
1%
2%
3%
4%
Babies with an Apgar score < 7 at 5 minutes
Effect of maternal characteristics on 
5-minute Apgar score
The characteristics of women and birthing people experiencing IOL may have an impact on their baby’s 5-minute 
Apgar score. Statistical modelling has been used to explore the maternal characteristics that may influence the Apgar 
score of the baby, while controlling for other factors. These results are summarised in a margins plot (Figure 4). 
Detailed model results can be found in Table 6 in the Methods and Results document.
Babies born to women and birthing people in Scotland and Wales had a higher likelihood of being assigned an Apgar 
score less than 7 at 5 minutes following IOL compared to those born in England. No association was found between 
maternal age and likelihood of an Apgar score of less than 7 at 5 minutes after birth. Babies born to women and 
birthing people from the most deprived IMD quintiles (Q4 and Q5) were more likely to have an Apgar score of less 
than 7 at 5 minutes compared to those from the least deprived quintile (Q1). Babies born to women and birthing 
people from Black ethnic groups were more likely to have an Apgar score of less than 7 at 5 minutes and babies born 
to those from Asian and the ‘Other’ ethnic groups were less likely, compared to babies born to white women and 
birthing people. A similar pattern between 5-minute Apgar score and maternal ethnic group was reported for the 
whole maternity population in the 2021 NMPA report Ethnic and Socio-economic Inequalities in NHS Maternity and 
Perinatal Care for Women and their Babies. 
Babies born to women and birthing people giving birth for the first time, and to those who had previously given birth 
by caesarean had a higher likelihood of being assigned an Apgar score of less than 7 at 5 minutes, compared to those 
who had previously given birth vaginally.
Several of the maternal characteristics that were examined for a relationship between IOL and caesarean birth or 
5-minute Apgar score are the same characteristics which may directly or indirectly influence clinical decision-making 
regarding whether an induction should be offered. Body Mass Index (BMI) and pre-pregnancy conditions such as 
diabetes and hypertension were not included in the model due to insufficient data completeness.
Figure 4: Margins plot showing the estimated likelihood of an Apgar score of less than 7 at 5 minutes following IOL
Country
Gestation at birth 
(completed weeks)
Maternal age 
(years)
Index of 
Multiple 
Deprivation
Ethnic group
Parity
10

11
Unanswered questions about IOL 
While national maternity data has been able to offer some insights into the mode of birth and 5-minute Apgar score 
following IOL, there are a number of questions that remain unanswered. This is either due to key data variables being 
suboptimally designed, data being recorded with poor completeness, or data not being readily available in specific 
freestanding variables. 
These questions include:
•	 How often do women and birthing people decline IOL?
•	 What are the most common indications for induction of labour?
•	 Which methods of induction are most frequently used?
•	 What is the average duration from commencing induction to being transferred to a labour suite?
•	 What proportion of IOL are unsuccessful?
The quality and completeness of the data that may answer some of these questions differs. For example, diagnostic 
codes for an unsuccessful induction of labour were identified for 6% of all inductions. However when examined at a 
trust/board level, these rates varied from 0% to 20%, raising concerns about the validity and accuracy of the coding 
for this finding. 
An unsuccessful IOL may be considered as one which does not progress sufficiently to the point of ‘established 
labour’, defined as regular contractions and progressive dilation of the cervix from 4cm; when this occurs many 
women and birthing people may consider a caesarean birth. Interpretation of this finding is further complicated 
by a lack of consensus definition for unsuccessful IOL. While the literature agrees that concluding an IOL has been 
unsuccessful should not occur before oxytocin is administered, different definitions have been proposed with varying 
duration of oxytocin administration. In clinical practice, IOL is sometimes declared/recorded as unsuccessful before 
oxytocin is administered. It is also possible for an IOL to successfully start labour but the woman or birthing person 
still experiences a caesarean in later labour; however, this would not be considered an unsuccessful induction.

Research Priorities
Commissioners of research including the National Institute for Health and Care Research (NIHR) and UK 
Research and Innovation (UKRI) alongside the Royal Colleges, researchers and other stakeholders should 
prioritise induction of labour research addressing the following questions: 
•	
Is it possible to predict mode of birth following IOL?
•	
Which methods/regimens of induction are most likely to result in successful labour onset?
•	
How can the birth experience around IOL be improved?
•	
How do outcomes compare between induced and spontaneous labour?
•	
Does the duration of the induction process influence the outcomes?
•	
What is the rate of maternal adverse outcomes following IOL?
•	
How does IOL influence birth experiences in future pregnancies?
•	
How do women and birthing people describe their experiences during and following induction?
•	
What are the outcomes (e.g. neonatal unit admission, adverse outcomes, use of antibiotics) 	
	
	
for babies following induction?
•	
How do the social determinants of health impact IOL care and outcomes?
12

Funding Status
The National Maternity and Perinatal Audit is commissioned by the Healthcare Quality 
Improvement Partnership (HQIP) and funded by NHS England and the Governments of 
Wales and Scotland as part of the National Clinical Audit and Patient Outcomes Programme. 
© 2025 Healthcare Quality Improvement Partnership (HQIP)
Please cite as: NMPA Project Team. National Maternity and Perinatal Audit: Induction of Labour Snapshot Audit, Based on births in NHS maternity services in 
England, Scotland and Wales during 2023. RCOG: London, 2025.
For further information and resources please visit the NMPA website, where 
you can also subscribe to the email newsletter for regular audit updates:
             www.maternityaudit.org.uk
Alternatively you can contact us at: xxx@xxx.xx
This report was prepared by the NMPA Project Team: 
Dr Amar Karia, Clinical Fellow (Obstetrics); Fran Carroll, Head of Clinical Quality Projects; 
George Dunn, Audit Lead; Alissa Frémeaux, Statistician; Dr Ipek Gurol-Urganci, Senior 
Methodological Advisor;  Dr James Harris, Senior Clinical Lead (Midwifery); Emma 
Heighway, Project Coordinator; Buthaina Ibrahim, Statistician; Professor Asma Khalil, 
Senior Clinical Lead (Obstetrics); Amy Lloyd, Project Coordinator; Professor Sam Oddie, 
Senior Clinical Lead (Neonatology); Kirstin Webster, Clinical Fellow (Neonatology); 
Professor Jan van der Meulen, Senior Methodologist and Audit Chair.
We would like to thank the NMPA Clinical Reference Group (CRG), Women and Families 
Involvement Group (WFIG) and our Induction of Labour Lived Experience Group for their 
valuable expert input to this report. 
The NMPA is supported by the RCOG Clinical Quality team, and the NMPA Project Board 
chaired by Mrs Geeta Kumar, Consultant Obstetrician and Gynaecologist and RCOG Vice 
President for Clinical Quality.
Acknowledgements