The Sono-VE Study: Assessing the Acceptability and Feasibility of Transperineal Ultrasound and Developing an Ultrasound Based Predictive Model for Labour Outcome.
Conditions: Placenta Praevia, Vaginismus
Sponsor: Imperial College London

The Sono-VE Study: Assessing the acceptability and feasibility of transperineal ultrasound and developing an 
ultrasound based predictive model for labour outcome-v3 
 
              
 
 
Version 3                          19th February 2015                                             Page 1 of 41 
 
 
 
The Sono-VE Study: Assessing the acceptability and 
feasibility of transperineal ultrasound and developing an 
ultrasound based predictive model for labour outcome.  
 
February 2015 
 
Main Sponsor 
Imperial College London 
Study coordination centre 
IRDB Hammersmith Hospitals 
REC/NRES Reference 
15/LO/0227 
Version Number 
V3 
 
Effective Date 
 
Author 
Dr Sana Usman 
Protocol authorised by: 
Date: 
 
 
 
Date and Signature:  
 
 
 
 
 
 
 
 
 
 
 
 
 
 

Assessing the acceptability and feasibility of transperineal ultrasound and developing an ultrasound based predictive 
model for labour outcome, the sonopartogram-v3 
 
 
 
Version 3 
19th February 2015 
Page 2 of 41 
Study Management Group 
 
Principal and Chief Investigator: 
Mr Christoph Lees MD MRCOG 
Consultant in Obstetrics and Feto-maternal Medicine 
Centre for Fetal Care, Queen Charlotte’s & Chelsea Hospital 
Du Cane Road, London W12 0HS 
E-mail: christoph.lees@imperial.nhs.uk 
Tel: +44 (0)208 383 3998  
 
Study Management: 
Miss Sana Usman BSc MBBS DFSRH MRCOG 
Project Manager 
Clinical Research Fellow 
Centre for Fetal Care 
Queen Charlotte’s & Chelsea Hospital 
Imperial College London, Hammersmith Campus 
Du Cane Road, London W12 0TR 
Tel: 0203 313 5161 
Email: s.usman@imperial.ac.uk 
 
Study Coordination Centre 
Imperial College Healthcare NHS Trust 
Queen Charlottes and Chelsea Hospital 
Du Cane Road 
London 
W12 0HS 
 
All clinical queries should be directed to Dr Sana Usman (contact details as 
above). 
 
Collaborators 
 

Assessing the acceptability and feasibility of transperineal ultrasound and developing an ultrasound based predictive 
model for labour outcome, the sonopartogram-v3 
 
 
 
Version 3 
19th February 2015 
Page 3 of 41 
Professor Phillip Bennett BSc PhD MD FRCOG 
Professor in Obstetrics and Gynaecology 
Director of the Institute of Reproductive and Developmental Biology  
Queen Charlotte’s & Chelsea Hospital 
Imperial College London, Hammersmith Campus 
Du Cane Road London W12 0HS 
Tel: +44 (0)20 7594 2176 
E-mail: p.bennett@imperial.ac.uk 
 
Professor Tom Bourne PhD FRCOG 
Consultant Gynaecologist 
Early Pregnancy Assessment Unit 
Imperial College London, Hammersmith Campus  
Queen Charlotte’s and Chelsea Hospital 
Du Cane Road, London W12 0HS 
Tel: 0207 636 6765 Mobile: 07768076797 
E-mail: womensultrasound@btinternet.com  
 
Professor Torbjørn Moe Eggebø MD PhD 
Associate Professor and Chair, National Center for Fetal Medicine 
St. Olavs University Hospital 
Norwegian University of Science and Technology 
N-7006 Trondheim 
Mobile phone  +47 926 99 433 
Email: torbjorn.eggebo@ntnu.no  
 
Professor Dirk Timmerman MD PhD FRCOG 
Professor in Obstetrics and Gynaecology, KU Leuven 
UZ Leuven, Campus Gasthuisberg, 
Herestraat 49,  
3000 Leuven, Belgium 
Tel: +32 16 34 42 01 
Email: dirk.timmerman@uzleuven.be 

Assessing the acceptability and feasibility of transperineal ultrasound and developing an ultrasound based predictive 
model for labour outcome, the sonopartogram-v3 
 
 
 
Version 3 
19th February 2015 
Page 4 of 41 
 
Dr Jacqueline Dunkley-Bent PhD 
Director of Midwifery  
Women's & Children's,  
Imperial College Healthcare NHS Trust, 
Praed Street, 
United Kingdom  
W2 1NY 
Phone number +44 02033122289 
Email: jacqueline.dunkleybent@imperial.nhs.uk 
 
Statistician 
 
Dr Charlotte Wilhelm-Benartzi Bsc, MPH, PhD 
Biostatistician 
Imperial College  
Institute of Reproductive Developmental Biology 
Hammersmith Campus 
Du Cane Road 
London  
W12 0HS 
Tel: +44 (0)20 7594 2125 
Email: c.wilhelm-benartzi@imperial.ac.uk 
 
Professor Ben Van Calster PhD 
KU Leuven Department of Development and regeneration   
Herestraat 49 
B-3000 Leuven, Belgium 
+32 16 321925 (tel)  
Email: ben.vancalster@med.kuleuven.be 
 
Data Analytics 
 

Assessing the acceptability and feasibility of transperineal ultrasound and developing an ultrasound based predictive 
model for labour outcome, the sonopartogram-v3 
 
 
 
Version 3 
19th February 2015 
Page 5 of 41 
Dr Arnaud JF Installé, MSc, PhD 
Department of Electrical Engineering ESAT 
STADIUS Center for Dynamical Systems, Signal Processing and Data 
Analytics 
KU Leuven 
Leuven, B-3001 
Belgium 
Phone: 32 16 328646 
Email: arnaud.installe@esat.kuleuven.be 
 
 
Sponsor 
 
Imperial College London is the main research sponsor for this study. 
 
For further information regarding the sponsorship conditions, please contact 
the Joint Research Compliance Office at: 
AHSC Joint Research Compliance Office, 
510A, 5th Floor Lab Block,  
Charing Cross Hospital, Fulham Palace Road 
W6 8RF 
Tel: 020 7594 1188  
Fax: 020 7594 1792  
http://www3.imperial.ac.uk/clinicalresearchgovernanceoffice 
 
Funding 
 
The British Medical Association through the Helen Lawson Grant has partly 
provided funding for the clinical fellow. The ultrasound machines provided are 
already available within the unit. There may be additional loaned ultrasound 
machines.  
 
This protocol describes the study and provides information about procedures 

Assessing the acceptability and feasibility of transperineal ultrasound and developing an ultrasound based predictive 
model for labour outcome, the sonopartogram-v3 
 
 
 
Version 3 
19th February 2015 
Page 6 of 41 
for entry. Queries relating to this study should be referred, in the first instance, 
to the Chief Investigator. 
 
This study will adhere to the principles outlined in the NHS Research 
Governance Framework for Health and Social Care (2nd edition). It will be 
conducted in compliance with the protocol, the Data Protection Act and other 
regulatory requirements as appropriate. 
 
 

The Sono-VE Study: Assessing the acceptability and feasibility of transperineal ultrasound and developing an ultrasound based 
predictive model for labour outcome-v3 
 
Version 3 
19th February 2015 
Page 7 of 41 
 
Table of Contents 
 
 
 
Content 
Page 
Number 
1. Study Summary 
    9-11 
2. Introduction 
     12 
2.1 Background 
     12 
2.2 Study Rationale and Hypothesis 
     13 
 
 
 
3. Study Objectives 
14 
 
 
4. Methodology and Design 
 
4.1 Study centre 
    14 
4.2 Study design    
    15 
4.3 Duration 
    15 
4.4 Inclusion criteria 
    15 
4.5 Exclusion criteria 
    16 
4.6 Withdrawal criteria 
    16 
4.7 Recruitment 
    16 
4.8 Consent and information leaflet 
    17 
4.9 Method of study 
    17 
4.10 Study Closure 
    21 
4.11 Documentation  
    21 
4.12 Patient engagement 
    21 
4.13 Dissemination to participants 
    22 
4.14 External peer review 
    22 
 
 
5. Study Outcome Measures 
    22 
5.1 Primary outcome measures 
    22 
5.2 Secondary outcome measures 
    23 
 
 
6. Adverse events and reporting procedure  
 
 
    23 

The Sono-VE Study: Assessing the acceptability and feasibility of transperineal ultrasound and developing an ultrasound based 
predictive model for labour outcome-v3 
 
Version 3 
19th February 2015 
Page 8 of 41 
6.1 Definitions 
    23 
6.2 Adverse events 
    24 
6.3 Reporting procedures 
    24 
 
 
7. Study Population and Sample Size 
   26 
7.1 Statistical and Data analysis 
   27 
 
 
8. Study supervision and monitoring 
   28 
 
 
9. Regulatory Issues 
   28 
9.1 Ethics approval 
   28 
9.2 Consent 
   28 
9.3 Data Collection and Confidentiality 
   29 
9.4 Data Storage and Archiving 
   29 
9.5 Indemnity 
   29 
9.6 Sponsor 
   29 
9.7 Audits and Inspections 
   29 
 
 
10. Study Management 
   30 
 
 
11. Publication policy 
   30 
 
 
12. References 
   31 
 
 
13. Appendix 
   35 
 
 
 
 
 
 
 
 
 
 

The Sono-VE Study: Assessing the acceptability and feasibility of transperineal ultrasound and developing an ultrasound based 
predictive model for labour outcome-v3 
 
Version 3 
19th February 2015 
Page 9 of 41 
 
1. STUDY SUMMARY  
 
TITLE  
  
The Sono-VE Study: Assessing the acceptability and feasibility of transperineal 
ultrasound and developing an ultrasound based predictive model for labour outcome. 
 
DESIGN  
 
This is a prospective observational study of transperineal ultrasound between 24-42 
weeks gestation and a prospective longitudinal observational study in all term (37-42 
weeks) labouring women. 
 
AIMS 
 
This study aims to firstly assess the effectiveness and acceptability of transperineal 
ultrasound in women presenting between 24 and 42 weeks gestation in comparison 
with digital vaginal examination (VE). Secondly, in all term (37-42 weeks) labouring 
women, we aim to create an ultrasound based labour record, “a sonopartogram” and 
from this develop a predictive model for the outcome of labour. 
 
NULL HYPOTHESIS 
 
That transperineal ultrasound  
1) is not an acceptable or feasible technique in comparison with digital VE 
between 24 and 42 weeks gestation  
2) cannot be used to predict labour outcome in term (37-42 weeks) labouring 
women.  
 
OUTCOME MEASURES 
 
Primary measures: 
 

The Sono-VE Study: Assessing the acceptability and feasibility of transperineal ultrasound and developing an ultrasound based 
predictive model for labour outcome-v3 
 
Version 3 
19th February 2015 
Page 10 of 41 
1. Assessing feasibility of ultrasound by comparison with digital 
vaginal examinations: 
 
• Digital vaginal examination: cervical dilatation, head station, caput, 
moulding, head position 
 
• Ultrasound: 
o Transabdominal Ultrasound: Fetal head position 
o Transperineal Ultrasound: Cervical dilatation, head-perineum 
distance, caput and moulding 
 
2. Acceptability of Transperineal Ultrasound to patients 
 
3. Dataset for predictive model of outcome of labour of Caesarean section 
due to failure to progress and/or fetal distress 
• Time to delivery  
• Mode of delivery 
• Primary indication for delivery 
o failure to progress 
o suspected fetal compromise 
 
Secondary measures:  
 
1. Neonatal outcome 
 
o Gender 
o Birth-weight 
o Apgar Scores at 1 and 5 minutes 
o Cord Gases 
§ Fetal acidosis defined as arterial pH <7.10 and base excess 
>12.0mmol/l 
o Neonatal unit admission within 24 hours 
o Neonatal morbidity 
 

The Sono-VE Study: Assessing the acceptability and feasibility of transperineal ultrasound and developing an ultrasound based 
predictive model for labour outcome-v3 
 
Version 3 
19th February 2015 
Page 11 of 41 
 
ELIGIBILITY 
 
All pregnant women booked at Imperial College Healthcare NHS Trust between the 
ages of 18 and 44 able to give consent  
 
DURATION 
 
The duration of the study is 3 years.  
 
Keywords 
Preterm, PPROM, labour, intrapartum, vaginismus, placenta praevia, transperineal 
ultrasound. 
 
 

The Sono-VE Study: Assessing the acceptability and feasibility of transperineal ultrasound and developing an ultrasound based 
predictive model for labour outcome-v3 
 
Version 3 
19th February 2015 
Page 12 of 41 
2. 
Introduction 
 
2.1 Background 
 
Introduction  
Currently, all women admitted to St Marys Hospital (SMH) and Queen Charlotte’s 
and Chelsea Hospital (QCCH) in common with delivery units throughout the world, 
undergo internal digital vaginal examination (digital VE) when they are thought to be 
in labour or where a diagnosis of labour needs to be discounted. Where labour is 
established, these digital VEs are characteristically performed every 4 hours or more 
frequently should concerns arise. The digital VE provides information about the 
descent through the birth canal of the presenting fetal part (usually the head), its 
position (which way around the baby’s presenting part is) and the dilatation of the 
cervix.  
 
The digital VE is an age-honoured practice however multiple examinations have 
been linked to ascending infection to the fetus1, chorioamnionitis and endometritis as 
well as reduced time to delivery in preterm labour1. It may also be an uncomfortable 
experience for the labouring woman2. 
 
It is contraindicated in some circumstances, such as Placenta Praevia or Preterm 
Prelabour Rupture Of Membranes (PPROM). For some women with a fear of 
childbirth, previous sexual trauma or vaginismus, digital VEs are especially traumatic 
and for these women special arrangements are usually made to avoid digital VE 
except where absolutely necessary. Irrespective of these concerns, digital VE is a 
notoriously subjective technique and agreement between observers is frequently 
poor.3,4 There is no way of objectively recording the findings as these are denoted 
purely by ‘feel’ and recorded in the notes as such, in relation to anatomical 
landmarks in the maternal pelvis and fetus. The findings are classically recorded on 
a ‘partogram’, a graphical representation of the progress of labour5. 
 
It has recently become possible to make assessments more objectively using 
ultrasound6,7. The favoured technique is transperineal ultrasound, where an 
ultrasound transducer encased in a clean cover is placed on the mother’s perineum 

The Sono-VE Study: Assessing the acceptability and feasibility of transperineal ultrasound and developing an ultrasound based 
predictive model for labour outcome-v3 
 
Version 3 
19th February 2015 
Page 13 of 41 
but not in the vagina8-11 and assessments of the descent of the presenting part of the 
baby12,13, its position and cervical dilatation14 can be made within 1-2 minutes and 
without exerting undue pressure (Figures 1-2). These measurements can be saved 
as ultrasound images and compared or assessed offline and plotted graphically as 
an ultrasound partogram, a sonopartogram15(Figure 3). This would indicate 
Caesarean sections due to failure to progress. 
 
Recently, research has shown that fetal Doppler examination demonstrating cerebral 
distribution (low cerebro-umbilical [C/U: MCA/PI] ratio) in advance of labour may be 
able to predict emergency Caesarean sections16. This challenges previously thought 
to be protective effect of cerebral redistribution17 to perfuse the brain secondary to 
hypoxic insult and may help us to develop a model for Caesarean sections for 
presumed fetal distress. 
 
2.2 Study Rationale and Hypothesis 
 
Several studies have assessed the accuracy of transabdominal ultrasound in 
comparison with digital VE in determining fetal head position18-21. These have 
concluded that digital VE fails to identify the correct fetal head position in the majority 
of cases, especially at cervical dilatation ≤3-4cm. Although transperineal ultrasound 
has been used pre-labour to predict the likelihood of PPROM patients going into 
labour22, its feasibility has not yet been assessed in the investigation and 
management of women either presenting with or established in labour. Initial studies 
have assessed head descent12 and rotation23 and angle of progression in labour13,24 
to assess the second stage of labour to predict the likelihood of spontaneous vaginal 
delivery, instrumental delivery or Caesarean section. However, there have not been 
any studies directly assessing the feasibility of transperineal ultrasound scans.  
 
We hypothesise that transperineal ultrasound will be a feasible and acceptable 
technique in comparison with digital vaginal examinations for 24-42 weeks gestation.  
 
Using the data gathered in term patients, we will develop a model to predict 
pregnancy outcomes. This may aid in delivery of care to pregnant women by 
providing a real-time online calculation tool for the likelihood of vaginal delivery and 
length of labour based on repeat ultrasound measurements.  This will allow a more 

The Sono-VE Study: Assessing the acceptability and feasibility of transperineal ultrasound and developing an ultrasound based 
predictive model for labour outcome-v3 
 
Version 3 
19th February 2015 
Page 14 of 41 
accurate prediction of the mode of delivery and reduce the number of vaginal 
examinations. This will improve the information available to women and their birth 
partners about the progress of their labour.  
 
We anticipate improvements to women’s health with additional information allowing 
better decision-making during labour enhancing the accurate recording of labour to a 
recordable skill. Universally, it may reduce the frequency of intrusive internal 
examinations and associated infection and will also be potentially useful in allowing 
the assessment of women in whom digital VE is traumatic or contra-indicated. 
 
Overall, it may create a paradigm shift on delivery units in an area where the 
standard assessments have not changed in over one hundred years allowing better 
provision of resources. 
 
3. Study Objectives 
 
Primary objectives: 
 
1. Feasibility of transperineal ultrasound scanning  
2. Acceptability of transperineal ultrasound scanning 
3. Creation of a “Sonopartogram” (Figure 3); an ultrasound based labour record 
4. Prediction model of time to delivery and mode of delivery at term 
• Caesarean section due to failure to progress and/or fetal distress 
 
Secondary objectives: 
 
1. Creation of a digital representation of the progress of labour (Figure 4). 
 
4. Methodology and Design 
 
4.1  Study Centre 
 
The study will be conducted at Queen Charlotte’s and Chelsea Hospital (Primary 
centre of the study) and St Marys Hospital at Imperial College Healthcare NHS Trust.  

The Sono-VE Study: Assessing the acceptability and feasibility of transperineal ultrasound and developing an ultrasound based 
predictive model for labour outcome-v3 
 
Version 3 
19th February 2015 
Page 15 of 41 
 
There will be: 
- 
A named individual (Clinical Research Fellow) in the relevant Study centre 
responsible for co-ordinating the project locally, and reporting directly to the 
chief investigators known as the project manager 
- 
Regular inspection by the project manager, under the supervision of the chief 
investigator, will be carried out ensuring that both the service (literature, 
communication, documentation, supervision and logistics) and facilities 
(Ultrasound, equipment and space) are of high standards.  
- 
All those who contribute are experienced in ultrasound. Suitably trained 
doctors and midwives (including research midwives) may contribute data to 
study where this is agreed in advance with the Principal Investigator. 
- 
This study will form part of a PhD thesis and/or other higher degrees. 
 
4.2 Design 
 
This is a prospective observational study of transperineal ultrasound between 24-42 
weeks gestation and a prospective longitudinal observational study in all term (37-42 
weeks) labouring women. 
 
4.3 Duration 
 
The duration of the study is 3 years.  
 
4.4  Inclusion Criteria 
 
- 
Gestation 24-42 completed weeks at study entry 
- 
Aged 18-44  
- 
Cephalic 
- 
Singleton pregnancies 
- 
Nulliparous  
- 
Multiparous (excluded for the term predictive model group) 
- 
Multiple pregnancies (excluded for the term predictive model group) 
- 
Established (Active) phase of labour (included for the term predictive model 
group) 

The Sono-VE Study: Assessing the acceptability and feasibility of transperineal ultrasound and developing an ultrasound based 
predictive model for labour outcome-v3 
 
Version 3 
19th February 2015 
Page 16 of 41 
o Clinician opinion that patient is in the established phase of labour 
according to the current NICE guidelines25 
 
4.5 Exclusion Criteria 
 
- 
Younger than 18 years. 
- 
Imminent iatrogenic intention to deliver 
- 
Life threatening maternal or fetal compromise needing immediate medical 
attention and/or delivery 
- 
Women who in the opinion of the researcher by virtue of language or learning 
impairment would be unable to give fully informed consent to the study. 
- 
Miscarriage 
- 
Intra-uterine death  
- 
Previous cervical surgery eg. cone biopsy, cervical cerclage. Note- Single 
LLETZ is not excluded. 
- 
Non-cephalic presentations 
- 
Multiple pregnancies (for the term predictive model group) 
- 
Multiparous patients (for the term predictive model group) 
- 
Not in established labour (for the term predictive model group) 
 
4.6  Withdrawal Criteria 
 
 Patients may be withdrawn from the study at any stage and all data captured in 
relation to their participation may be destroyed if they so request. 
 
4.7 Recruitment methods 
 
All groups will be identified by the project manager and emphasis will be placed on 
recruiting patients antenatally as much as possible. The project manager is a 
member of the participants care team. The project manager will organise the 
recruitment and written consent, which can be obtained by any one of the research 
team members that will have been trained (expected to be up to 8 doctors and 
midwives on the delivery units of both QCCH and SMH although primarily it will be at 
QCCH). These doctors and midwives will undergo induction and then maintenance 
training in the study protocol, transperineal ultrasound and data entry/governance 

The Sono-VE Study: Assessing the acceptability and feasibility of transperineal ultrasound and developing an ultrasound based 
predictive model for labour outcome-v3 
 
Version 3 
19th February 2015 
Page 17 of 41 
including GCP training. Where a midwife performs the ultrasound examination, it will 
not be the same midwife responsible for the ongoing care and digital VEs of that 
woman: another midwife or doctor should perform the examination. Where a doctor 
performs the ultrasound examination, that doctor will not make the decision for a 
course of action, it will normally be made by the next most senior doctor. Ultrasound 
examinations should not be the basis for a course of action unless a clinically 
unexpected and important situation that would change clinical management is not 
disclosed through digital VE but is through ultrasound.  
 
Ahead of recruitment, a press release on the Imperial College Healthcare NHS Trust 
and Imperial College website will display recruitment posters. We will advertise on 
other relevant websites and display recruitment posters at other sites. 
 
Recruitment areas 
• Patient’s attending the Early Pregnancy Unit (£20 weeks gestation) 
• Antenatal Clinic (all trimesters) 
• Parent Craft classes (second and third trimester) 
• Fetal Medicine Unit (all trimesters) 
• Day Assessment Unit, Maternity Triage and Labour Ward (³20 weeks 
gestation).  
 
The project manager will organise a formal meeting with the charge nurses from all 
areas to inform them of the study upon ethics approval.  
 
4.8 Consent and Information leaflet  
(see supporting documents) 
All participating patients will be consented prior to enrolment, and will receive a full 
explanatory information leaflet. All recruiters will be GCP trained.  
 
4.9 Method of study 
 
For each of the two individual studies, a separate information leaflet detailing the 
purpose will be provided to all potential recruits (see supporting documents and flow 
chart- figure 7). If a patient is willing to participate, written consent will be obtained.  

The Sono-VE Study: Assessing the acceptability and feasibility of transperineal ultrasound and developing an ultrasound based 
predictive model for labour outcome-v3 
 
Version 3 
19th February 2015 
Page 18 of 41 
 
The patients will then take part in a researcher led Reproductive Health interview 
which includes routine demographic data and information regarding previous 
obstetric, medical and gynaecological history, as well as questions regarding 
psycho-sexual health history. Where possible, the demographic and sensitive 
information relating to participants such as the ethnicity, obstetric and mental health 
history will be obtained by the researcher from the participants notes.  All information 
will be entered into a secure study database. Patients will be identified by study 
number only. 
 
During the ultrasound examination, women will be in the supine position with flexed 
hips and knees and the bladder empty as previously described. Healthcare 
professionals will be blinded to the ultrasound findings and these findings will also 
not be disclosed to the parents. Another doctor or midwife will perform all the 
ultrasound examinations.  
 
Fetal position will be assessed with a transabdominal scan and recorded with half 
hourly divisions7. Thereafter, the transducer will be placed transperineally at the level 
of the posterior fourchette in a transverse position (Figure 1), and cervical dilatation14 
and head-perineum distance (HPD) measured as previously described22. Caput 
succedaneum will be measured in a sagittal transperineal scan9,15 (Figure 1). 
Moulding will be assessed as either present or not12.  
 
The healthcare professional will perform digital vaginal examination assessing 
cervical dilatation, fetal head descent and position. The descent will be categorised 
using the WHO classification of fetal head station with the ischial spines as reference 
point 0, -5cm at the pelvic inlet and +5cm at the pelvic outlet27.   
 
Acceptability and Feasibility: 
 
In this group, patients will also be asked to complete two additional researcher-led 
questionnaires (modified from a previously validated questionnaire -see supporting 
documents). This will be in the form of a “pre-study” and a “post-study” questionnaire 
which will focus on the patient’s views regarding vaginal examinations and the 
transperineal scanning method to assess the acceptability of the technique.  

The Sono-VE Study: Assessing the acceptability and feasibility of transperineal ultrasound and developing an ultrasound based 
predictive model for labour outcome-v3 
 
Version 3 
19th February 2015 
Page 19 of 41 
 
Transperineal ultrasound will then be carried out between gestations 24-42 weeks 
when a vaginal or speculum examination is otherwise also required to assess 
acceptability and feasibility. This scan will be done either immediately before or after 
the digital vaginal examination and the timing in relation the digital vaginal 
examination will be recorded. 
 
 
Predictive Model: 
 
In the predictive model group, there are no additional questionnaires. An admission 
ultrasound scan will be performed when the patient is deemed to be in established 
labour by the attending clinician. Subsequent scans will be performed as required at 
the time of routine clinical examinations typically between 2-4 hours apart.   
 
The admission ultrasound scan will include if feasible fetal Doppler assessment of 
the umbilical artery, the cerebro-umbilical ratio (C/U: MCA/PI)16. Amniotic fluid index 
will also be measured. Fetal position will be assessed with a transabdominal scan 
and recorded as described above.  
 
Dataset 
Fixed variables 
 
Maternal 
Gestation 
BMI, Age28, Parity, Height, Ethnicity 
Contraindication to vaginal examinations 
Reason for avoidance of vaginal examinations 
 
Fetal 
EFW if known 
Singleton 
Multiple 
 
Intrapartum 
Non-USS: 
Rupture of Membranes Yes/No: If Yes: Time 
Spontaneous onset of labour Yes/No: If Yes: Time 
Induction of Labour with prostaglandins Yes/No: If Yes: Time at insertion of 
prostaglandin 

The Sono-VE Study: Assessing the acceptability and feasibility of transperineal ultrasound and developing an ultrasound based 
predictive model for labour outcome-v3 
 
Version 3 
19th February 2015 
Page 20 of 41 
Syntocinon Yes/No: If Yes: Time 
Epidural analgesia Yes/No: If Yes: Time 
 
Modifiable parameters 
 
USS Parameters: modified as labour progresses 
-head position (TA ultrasound scan) 
-cervical dilatation 
-head-perineum distance 
-caput 
-moulding 
 
 
Prolonged first stage of labour will be diagnosed according to national guidelines set 
in the UK by the National Institute of Health and Clinical Excellence (NICE) 
guidelines (cervical dilatation of < 2 cm in 4 hours)25. 
 
If recruited to the study, all patients will undergo normal clinical management with 
digital VEs or speculum examination performed as planned and in addition, 
ultrasound examinations before the digital VE/speculum by trained professionals. 
These ultrasound examinations will be blinded to the normal caregivers (midwives or 
doctors) so that they do not influence clinical management, though for practical 
reasons it will not be possible to blind the ultrasound operator to the clinical findings.  
 
In women where digital vaginal examinations are contraindicated, we will compare 
ultrasound observations to those obtained by speculum. In all other women, 
ultrasound measurements will be compared to the corresponding digital vaginal 
examinations. In women who decline digital vaginal examinations for psychological 
reasons, this will be noted.  
 
There are no additional visits outside the normal care pathway for the patient. 
The length of years of obstetric experience of the healthcare professional carrying 
out the digital vaginal examinations, speculums, ultrasound scan and the delivery will 
be recorded.  
 
Study Timeline 
 
The study will run according to the following timeline: 

The Sono-VE Study: Assessing the acceptability and feasibility of transperineal ultrasound and developing an ultrasound based 
predictive model for labour outcome-v3 
 
Version 3 
19th February 2015 
Page 21 of 41 
• 
Months 0-3: Ethics completion, staff training, and setting up web based study 
screens 
• 
Months 3-27: Active study recruitment 
• 
Months 27-36: Analyses and write up of an ultrasound based labour record 
(the sonopartogram) and  development of a predictive model.  
 
4.10 Study Closure 
 
Data will be collected over the 24 months data collection period.  
 
4.11 Documentation  
 
Recruitment of patients will be noted in the NHS notes. Where photographs of the 
ultrasound images were obtained, these will be saved securely onto an NHS 
computer and/or printed in hard copy, which will be filed in a locked secure area. 
Data will be stored for a minimum of 10 years after completion of study, including the 
follow up period.  
 
4.12 Patient Engagement 
 
Patients were involved in the creation of the initial study15 through the Cambridge 
Maternity Services Liaison Committee, and their feedback from the participation 
helped shape this research proposal. We have received outline support for the 
project from the RCOG Intrapartum Care Clinical Study Group led by Dr Sara 
Kenyon in 2012 and lay representatives, though this latest iteration of the project 
design has not yet been submitted to the group. Patient views are important in 
designing this study to maximise recruitment and we have previously consulted the 
RCOG to invite lay members to steering committees of a similar previous study 
(Transvaginal Ultrasound Scanning – Hazard and Clinical Practice, awarded CCF 
Grant, 2012). We will arrange Parent Focus Group Meetings alongside their hospital 
Parent Craft classes so they do not have to devote extra time to this and explore 
how they feel this research should be conducted. As well as active recruitment, they 
will also be allowed to self-volunteer to take part in the study with leaflets in various 
clinical areas. The Imperial Trust website also fosters public interest by including 

The Sono-VE Study: Assessing the acceptability and feasibility of transperineal ultrasound and developing an ultrasound based 
predictive model for labour outcome-v3 
 
Version 3 
19th February 2015 
Page 22 of 41 
links to the Clinical Research Network Coordinating Centre, Women’s Health 
Research Centre and to the ongoing various projects.  
 
4.13 Dissemination to participants 
 
Participants, if consented, will be emailed the results of the study in the form of 
anonymised published posters and papers.  
 
4.14 External peer review 
 
An earlier version of this protocol has been subject to external peer review by the 
British Medical Association leading to external funding (Helen Lawson Grant, 
awarded July 2014) 
 
5. 
Study Outcome Measures 
 
5.1 Primary measures: 
 
1. Assessing feasibility of ultrasound by comparison with digital 
vaginal examinations: 
 
• Digital vaginal examination: cervical dilatation, head station, caput, 
moulding, head position 
 
• Ultrasound: 
o Transabdominal Ultrasound: Fetal head position 
o Transperineal Ultrasound: Cervical dilatation, head-perineum 
distance, caput and moulding 
 
2. Acceptability of Transperineal Ultrasound to patients 
 
3. Dataset for predictive model of outcome of labour of Caesarean section 
due to failure to progress and/or fetal distress 
• Time to delivery  

The Sono-VE Study: Assessing the acceptability and feasibility of transperineal ultrasound and developing an ultrasound based 
predictive model for labour outcome-v3 
 
Version 3 
19th February 2015 
Page 23 of 41 
• Mode of delivery 
• Primary indication for delivery 
o failure to progress 
o suspected fetal compromise 
 
5.2 Secondary measures:  
 
1. Neonatal outcome 
 
o Gender 
o Birth-weight 
o Apgar Scores at 1 and 5 minutes 
o Cord Gases 
§ Fetal acidosis defined as arterial pH <7.10 and base excess 
>12.0mmol/l 
o Neonatal unit admission within 24 hours 
o Neonatal morbidity 
 
 
6. Adverse events and reporting procedure 
 
RISK ASSESSMENT - This study will not involve any risk to the participants.  There 
are no predicted risks associated with the additional transabdominal and 
transperineal ultrasound scan. The scans will be used at the same settings and 
duration as routine ultrasound. We will be using probe covers and disinfection spray 
to clean the probe between patients.  
 
The patient will be managed accordingly in concordance with local guidance and 
follow up arrangements will be made. The patient will still be followed up for the 
purposes of the study. 
 
6.1 Definitions 
 
Adverse Event (AE): Any untoward medical occurrence in a patient or clinical study 

The Sono-VE Study: Assessing the acceptability and feasibility of transperineal ultrasound and developing an ultrasound based 
predictive model for labour outcome-v3 
 
Version 3 
19th February 2015 
Page 24 of 41 
subject.  
Serious Adverse Event (SAE): Any untoward and unexpected medical occurrence 
or effect that:  
- 
Results in death  
- 
Is life-threatening – refers to an event in which the subject was at risk of 
death at the time of the event; it does not refer to an event which 
hypothetically might have caused death if it were more severe 
- 
Requires hospitalisation, or prolongation of existing inpatients’ 
hospitalisation  
- 
Results in persistent or significant disability or incapacity  
- 
Is a congenital anomaly or birth defect  
 
6.2 Adverse events 
 
There are no risks to the patients or the fetus from this study. There is also no 
evidence to suggest any harm to the mother or the pregnancy associated with the 
use of ultrasound. Patients may experience slight discomfort when the probe is 
placed, though this is usually considered less than the discomfort experienced with 
vaginal examinations. We will be using probe covers and disinfection spray to clean 
the probe between patients. Medical judgement will be exercised in deciding whether 
an AE is serious in other situations. Important AEs that are not immediately life-
threatening or do not result in death or hospitalisation but may jeopardise the subject 
or may require intervention to prevent one of the other outcomes listed in the 
definition above, will also be considered serious.  
 
6.3 Reporting procedures 
 
All adverse events will be reported. Depending on the nature of the event the 
reporting procedures below will be followed. Any questions concerning adverse 
event reporting will be directed to the Chief Investigator in the first instance.  
 
Non serious AEs  
All such events, whether expected or not, will be recorded.  
 
Serious AEs  

The Sono-VE Study: Assessing the acceptability and feasibility of transperineal ultrasound and developing an ultrasound based 
predictive model for labour outcome-v3 
 
Version 3 
19th February 2015 
Page 25 of 41 
An SAE form will be completed and faxed to the Chief Investigator within 24 hours. 
However, relapse and death and hospitalisations for elective treatment of a pre-
existing condition do not need reporting as SAEs.  
All SAEs will be reported to the Chief Investigator who will determine if the event 
was:  
•  
Related- resulted from the administration of any of the research procedures; 
and  
•  
Unexpected- an event that is not listed in the protocol as an expected 
occurrence 
•            Unrelated- an event that is not related to the study  
 
Reports of related and unexpected SAEs will be submitted within 15 days of the 
Chief Investigator becoming aware of the event, using the NRES SAE form for non-
IMP studies. The Chief Investigator will also notify the Sponsor of all SAEs.  
Local investigators will report any SAEs as required by their Local Research Ethics 
Committee, Sponsor and/or Research & Development Office.  
 
Contact details for reporting adverse events: 
 
Chief Investigator: 
Mr Christoph Lees MD MRCOG 
Consultant in Obstetrics and Feto-maternal Medicine 
Centre for Fetal Care, Queen Charlotte’s & Chelsea Hospital 
Du Cane Road, London W12 0HS 
E-mail: christoph.lees@imperial.nhs.uk 
Tel: +44 (0)208 383 3998 
 
7. Study Population and Sample size 
 
Recruitment will start upon approval of the study. The infrastructure, research fellow, 
ultrasound machines, and the database are already in place, which ensure that the 
study can start promptly upon approval, without affecting or compromising routine 
clinical service provision.  
 

The Sono-VE Study: Assessing the acceptability and feasibility of transperineal ultrasound and developing an ultrasound based 
predictive model for labour outcome-v3 
 
Version 3 
19th February 2015 
Page 26 of 41 
We aim to recruit minimum number in the groups according to the following 
calculations29: 
 
Primary outcome:  
 
Acceptability 
 
In studies thus far, acceptability of transperineal ultrasound (with no or minimal pain) 
varies from 68%30 to 95%31 compared with 20% for vaginal examinations30. Using 
the lowest percentage of acceptability at 68%, with an alpha of 0.05 and a power of 
90%, the minimum sample size required is 42 patients. However, given that this area 
has been poorly researched before and the power calculation is purely indicative, we 
would expect to collect at least 100 questionnaires. 
 
Feasibility 
 
A recent study by our group has shown that 95%15 of transperineal ultrasound 
parameters can be obtained compared to 82% of digital vaginal examination 
parameters15. With an alpha of 0.05 and a power of 90%, the minimum sample size 
required is 250 patients.  
 
Labour prediction model 
 
For the labour prediction model, there are approximately 15 variables with 10 
patients needed per variable32-34 and an approximate 25% Caesarean section 
rate28,35,36 (the primary outcome) in the UK currently. This equates to 600 patients 
needed for the study.  
 
Calculation: 
15 x 10 x (100/25) = 600 patients 
 
 As already discussed above, for statistical power and significance, a minimum of 42 
and 250 patients is required for acceptability and feasibility respectively (24-42 
weeks). For the predictive modelling, 600 patients are required (37-42 weeks).  

The Sono-VE Study: Assessing the acceptability and feasibility of transperineal ultrasound and developing an ultrasound based 
predictive model for labour outcome-v3 
 
Version 3 
19th February 2015 
Page 27 of 41 
 
The majority of the patients for the acceptability and feasibility samples will be 
recruited from the predictive modelling group (gestation 37-42 weeks). However, to 
allow sufficient data collection for feasibility, acceptability and development of the 
model, at least 700 patients will be required. As the trust has an annual delivery rate 
of 9000 annually, over a 24-month data collection period with a delivery rate of 
18,000 across the trust, 700 patients (4%) sample size is achievable.  
 
 
7.1 Statistical and Data Analysis 
 
In both groups, data will be collected prospectively and compared with vaginal 
examinations. In the second group, there will also be additional longitudinal 
measurements. 
 
We will use a p value of <0.05 to indicate significance. 
 
All measurements will be entered online at the time of examination to a secure 
database on the Imperial College Healthcare NHS Trust shared server where the 
patient will be identified by study number only. The database entry page will be 
accessible to investigators on their login, though they cannot interrogate data already 
entered. The data rules will follow closely to those performed through the recently 
completed multicentre European TRUFFLE study of fetal growth restriction where 
ultrasound measurements were captured at the time of examination37. 
 
For 24-42 weeks assessment of acceptability and feasibility: 
 
Acceptability and preference will be tested using a questionnaire with Likert scale for 
discomfort, adapted from the W-DEQ Score38 
 
Feasibility of the ultrasound technique will be compared to digital VE for (a) total 
number of observations missing (head descent, position and cervical dilatation) 
during an admission on the delivery unit and (b) number of ultrasound examinations 
or digital VEs that could not be carried out for whatever reason where there was an 
intention to carry out a digital VE. 

The Sono-VE Study: Assessing the acceptability and feasibility of transperineal ultrasound and developing an ultrasound based 
predictive model for labour outcome-v3 
 
Version 3 
19th February 2015 
Page 28 of 41 
 
As a part of feasibility, Reproducibility between the ultrasound and digital VE 
techniques will be assessed both as a correlation (r) and agreement (using the Bland 
Altman method) between the ultrasound method and digital VE for head descent and 
cervical dilatation, and the Kappa statistic for head position.  
 
Term predictive model:  
 
The predictive value of intrapartum ultrasound parameters will be investigated using 
linear and logistic regression analyses. We will calculate the Receiver Operating 
Characteristic (ROC) curve with the Area Under the Curve (AUC) and associated 
positive and negative predictive values for delivery outcomes in the evaluation of 
transperineal ultrasound as a diagnostic tool. 
 
8. Study supervision and Monitoring 
 
Central and local supervision: the chief principal investigator at Imperial College 
London will be responsible for the protocol, quality control, interim analyses of the 
data, advice on progress and final analysis and reporting of the study. The Imperial 
Joint Research Compliance Office may audit the study as part of routine research 
governance.  
 
 
9. Regulatory Issues 
 
9.1 Ethical approval 
 
The Study Coordination Centre will obtain ethics approval from the XXX Research 
Ethics Committee. The study also has been submitted for Site Specific Assessment 
(SSA) at Imperial College Healthcare Trust for local Trust Research and 
Development approval.  
 
9.2 Consent 
 

The Sono-VE Study: Assessing the acceptability and feasibility of transperineal ultrasound and developing an ultrasound based 
predictive model for labour outcome-v3 
 
Version 3 
19th February 2015 
Page 29 of 41 
Consent to enter the study will be sought from each participant only after a full 
explanation has been given, an information leaflet offered and time allowed for 
consideration. Signed participant consent will be obtained. The patients GP will be 
informed of participation if the patient agrees. The right of the participant to refuse to 
participate without giving reasons will be respected.  
 
After the participant has entered the study the clinician will be expected to manage 
the patient in exactly the same way that would have been expected had the 
participant not entered the study. The clinician will be blind to the information 
obtained from ultrasound assessment. All participants are free to withdraw at any 
time from the protocol treatment without giving reasons and without prejudicing 
further treatment.  
 
9.3  Data Collection and Confidentiality 
 
A study identification number anonymising all patient data will be used to collect and 
store data on an NHS computer software programme or database. The data may be 
transferred to a Third Party within the European Union but this will be an anonymised 
way with the use of study identification number only. This may be by an online 
website with secure access only. The Chief Investigator will preserve the 
confidentiality of participants taking part in the study and is registered under the Data 
Protection Act. 
 
9.4 Data Storage and Archiving 
 
All data will be stored for 10 years in accordance with the Imperial College data 
archiving policy.  
 
9.5  Indemnity 
 
Imperial College London holds negligent harm and non-negligent harm insurance 
policies, which apply to this study.  
 
9.6  Sponsor 
 

The Sono-VE Study: Assessing the acceptability and feasibility of transperineal ultrasound and developing an ultrasound based 
predictive model for labour outcome-v3 
 
Version 3 
19th February 2015 
Page 30 of 41 
Imperial College London will act as the main sponsor for this study. Delegated 
responsibilities will be assigned to the NHS trusts taking part in this study. 
 
9.7  Audits and Inspections 
 
The study may be subject to inspection and audit by Imperial College London under 
their remit as sponsor and other regulatory bodies to ensure adherence to GCP and 
the NHS Research Governance Framework for Health and Social Care (2nd edition). 
Direct access to source data/documents as requested will be permitted. 
 
10. Study Management 
 
The day-to-day management of the trial will be co-ordinated through the Centre for 
Fetal Care at Queen Charlotte’s and Chelsea Hospital by Dr Sana Usman, the 
Project Manager. The week-by-week supervision will be by the Chief Investigator 
and the other collaborators who will form the study management group. 
 
11. Publication Policy 
 
All publications and presentations relating to the study will be authorised by the 
Study Management Group. The investigators will therefore be responsible for 
publication of the data. As such they are co-authors in all resulting clinically relevant 
papers, to which they made significant contributions. Co-authors will be included 
according to their contribution in the study and depending on the journals publication 
guidelines. 
 
12. References 
 
1. 
Westover T, Knuppel RA. Modern management of clinical chorioamnionitis. 
Infect Dis Obstet Gynecol. 1995;3(3):123–132. 
doi:10.1155/S1064744995000457. 
2. 
Ying Lai C, Levy V. Hong Kong Chinese women's experiences of vaginal 
examinations in labour. Midwifery. 2002;18(4):296–303. 
doi:10.1054/midw.2002.0326. 
3. 
Buchmann EJ, Libhaber E. Accuracy of cervical assessment in the active 
phase of labour. BJOG: An International Journal of Obstetrics & Gynaecology. 

The Sono-VE Study: Assessing the acceptability and feasibility of transperineal ultrasound and developing an ultrasound based 
predictive model for labour outcome-v3 
 
Version 3 
19th February 2015 
Page 31 of 41 
2007;114(7):833–837. doi:10.1111/j.1471-0528.2007.01386.x. 
4. 
Dupuis O, Silveira R, Zentner A, Dittmar A, Gaucherand P, Cucherat M, 
Redarce T, Rudigoz R-C. Birth simulator: reliability of transvaginal assessment 
of fetal head station as defined by the American College of Obstetricians and 
Gynecologists classification. Am J Obstet Gynecol. 2005;192(3):868–874. 
doi:10.1016/j.ajog.2004.09.028. 
5. 
Philpott RH. Graphic records in labour. Br Med J. 1972;4(5833):163–165. 
6. 
Akmal S, Kametas N, Tsoi E, Hargreaves C, Nicolaides KH. Comparison of 
transvaginal digital examination with intrapartum sonography to determine fetal 
head position before instrumental delivery. Ultrasound Obstet Gynecol. 
2003;21(5):437–440. doi:10.1002/uog.103. 
7. 
Akmal S, Tsoi E, Kametas N, Howard R, Nicolaides KH. Intrapartum 
sonography to determine fetal head position. J Matern Fetal Neonatal Med. 
2002;12(3):172–177. doi:10.1080/jmf.12.3.172.177. 
8. 
TUTSCHEK B, Braun T, Chantraine F, Henrich W. A study of progress of 
labour using intrapartum translabial ultrasound, assessing head station, 
direction, and angle of descent. BJOG: An International Journal of Obstetrics & 
Gynaecology. 2011;118(1):62–69. doi:10.1111/j.1471-0528.2010.02775.x. 
9. 
Hassan WA, TUTSCHEK B. INTRAPARTUM SONOGRAPHY: AN 
OPPORTUNITY FOR OBJECTIVE ASSESSMENT OF LABOUR. Fetal and 
Maternal Medicine Review. 2013;24(01):2–17. 
doi:10.1017/S0965539512000162. 
10. 
Torkildsen EA, Salvesen KÅ, Eggebø TM. Agreement between two- and three-
dimensional transperineal ultrasound methods in assessing fetal head descent 
in the first stage of labor. Ultrasound in Obstetrics & Gynecology. 
2012;39(3):310–315. doi:10.1002/uog.9065. 
11. 
Ghi T, Youssef A, Maroni E, Arcangeli T, De Musso F, Bellussi F, Nanni M, 
Giorgetta F, Morselli-Labate AM, Iammarino MT, Paccapelo A, Cariello L, 
Rizzo N, Pilu G. Intrapartum transperineal ultrasound assessment of fetal head 
progression in active second stage of labor and mode of delivery. Ultrasound 
in Obstetrics & Gynecology. 2013;41(4):430–435. doi:10.1002/uog.12379. 
12. 
Barbera AF, Pombar X, Perugino G, Lezotte DC, Hobbins JC. A new method 
to assess fetal head descent in labor with transperineal ultrasound. Ultrasound 
in Obstetrics & Gynecology. 2009;33(3):313–319. doi:10.1002/uog.6329. 
13. 
Levy R, Zaks S, Ben-Arie A, Perlman S, Hagay Z, Vaisbuch E. Can angle of 
progression in pregnant women before onset of labor predict mode of delivery? 
Ultrasound in Obstetrics & Gynecology. 2012;40(3):332–337. 
doi:10.1002/uog.11195. 
14. 
Hassan WA, Eggebø TM, Ferguson M, Lees C. Simple two-dimensional 
ultrasound technique to assess intrapartum cervical dilatation: a pilot study. 
Ultrasound in Obstetrics & Gynecology. 2013;41(4):413–418. 
doi:10.1002/uog.12316. 

The Sono-VE Study: Assessing the acceptability and feasibility of transperineal ultrasound and developing an ultrasound based 
predictive model for labour outcome-v3 
 
Version 3 
19th February 2015 
Page 32 of 41 
15. 
Hassan WA, Eggebø T, Ferguson M, Gillett A, Studd J, Pasupathy D, Lees 
CC. The sonopartogram: a novel method for recording progress of labor by 
ultrasound. Ultrasound in Obstetrics & Gynecology. 2014;43(2):189–194. 
doi:10.1002/uog.13212. 
16. 
Prior T, Mullins E, Bennett P, Kumar S. Umbilical venous flow rate in term 
fetuses: can variations in flow predict intrapartum compromise? Am J Obstet 
Gynecol. 2014;210(1):61.e1–61.e8. doi:10.1016/j.ajog.2013.08.042. 
17. 
Jensen A, Roman C, Rudolph AM. Effects of reducing uterine blood flow on 
fetal blood flow distribution and oxygen delivery. J Dev Physiol. 
1991;15(6):309–323. 
18. 
Sherer DM. Can sonographic depiction of fetal head position prior to or at the 
onset of labor predict mode of delivery? Ultrasound in Obstetrics & 
Gynecology. 2012;40(1):1–6. doi:10.1002/uog.11213. 
19. 
Akmal S, Tsoi E, Nicolaides KH. Intrapartum sonography to determine fetal 
occipital position: interobserver agreement. Ultrasound Obstet Gynecol. 
2004;24(4):421–424. doi:10.1002/uog.1065. 
20. 
Sherer DM, Miodovnik M, Bradley KS, Langer O. Intrapartum fetal head 
position I: comparison between transvaginal digital examination and 
transabdominal ultrasound assessment during the active stage of labor. 
Ultrasound Obstet Gynecol. 2002;19(3):258–263. doi:10.1046/j.1469-
0705.2002.00641.x. 
21. 
Souka AP, Haritos T, Basayiannis K, Noikokyri N, Antsaklis A. Intrapartum 
ultrasound for the examination of the fetal head position in normal and 
obstructed labor. J Matern Fetal Neonatal Med. 2003;13(1):59–63. 
doi:10.1080/jmf.13.1.59.63. 
22. 
Eggebø TM, Gjessing LK, Heien C, Smedvig E, Økland I, Romundstad P, 
Salvesen KÅ. Prediction of labor and delivery by transperineal ultrasound in 
pregnancies with prelabor rupture of membranes at term. Ultrasound in 
Obstetrics & Gynecology. 2006;27(4):387–391. doi:10.1002/uog.2744. 
23. 
Ghi T, Farina A, Pedrazzi A, Rizzo N, Pelusi G, Pilu G. Diagnosis of station 
and rotation of the fetal head in the second stage of labor with intrapartum 
translabial ultrasound. Ultrasound in Obstetrics & Gynecology. 
2009;33(3):331–336. doi:10.1002/uog.6313. 
24. 
Dückelmann AM, Bamberg C, Michaelis SAM, Lange J, Nonnenmacher A, 
Dudenhausen JW, Kalache KD. Measurement of fetal head descent using the 
“angle of progression” on transperineal ultrasound imaging is reliable 
regardless of fetal head station or ultrasound expertise. Ultrasound in 
Obstetrics & Gynecology. 2010;35(2):216–222. doi:10.1002/uog.7521. 
25. 
Clinical Excellence. Intrapartum care: care of healthy women and their babies 
during childbirth (CG190). London 2014. 2014:1–108. 
26. 
Eggebø TM, Hassan WA, Salvesen KÅ, Lindtjørn E, Lees CC. Sonographic 
prediction of vaginal delivery in prolonged labor: a two-center study. 

The Sono-VE Study: Assessing the acceptability and feasibility of transperineal ultrasound and developing an ultrasound based 
predictive model for labour outcome-v3 
 
Version 3 
19th February 2015 
Page 33 of 41 
Ultrasound in Obstetrics & Gynecology. 2014;43(2):195–201. 
doi:10.1002/uog.13210. 
27. 
Mathi M, Sanghvi H. Guidotti Rj; Major Contributors. Managing Complications 
in Pregnancy and Childbirth: a Guide for Midwives and Doctors. Geneva: 
Department of …. World Health Organisation; 2000. 
28. 
Ecker JL, Chen KT, Cohen AP, Riley LE, Lieberman ES. Increased risk of 
cesarean delivery with advancing maternal age: indications and associated 
factors in nulliparous women. Am J Obstet Gynecol. 2001;185(4):883–887. 
doi:10.1067/mob.2001.117364. 
29. 
Faul F, Erdfelder E, Lang A-G, Buchner A. G*Power 3: A flexible statistical 
power analysis program for the social, behavioral, and biomedical sciences. 
Behavior Research Methods. 2007;39(2):175–191. doi:10.3758/BF03193146. 
30. 
Meijer-Hoogeveen M, Stoutenbeek P, Visser GHA. Transperineal versus 
transvaginal sonographic cervical length measurement in second- and third-
trimester pregnancies. Ultrasound in Obstetrics & Gynecology. 
2008;32(5):657–662. doi:10.1002/uog.4093. 
31. 
Cicero S, Skentou C, Souka A, To MS, Nicolaides KH. Cervical length at 22-24 
weeks of gestation: comparison of transvaginal and transperineal-translabial 
ultrasonography. Ultrasound Obstet Gynecol. 2001;17(4):335–340. 
doi:10.1046/j.1469-0705.2001.00345.x. 
32. 
Peduzzi P, Concato J, Kemper E, Holford TR, Feinstein AR. A simulation study 
of the number of events per variable in logistic regression analysis. J Clin 
Epidemiol. 1996;49(12):1373–1379. doi:10.1016/S0895-4356(96)00236-3. 
33. 
Concato J, Peduzzi P, Holford TR, Feinstein AR. Importance of events per 
independent variable in proportional hazards analysis. I. Background, goals, 
and general strategy. J Clin Epidemiol. 1995;48(12):1495–1501. 
doi:10.1016/0895-4356(95)00510-2. 
34. 
Peduzzi P, Concato J, Feinstein AR, Holford TR. Importance of events per 
independent variable in proportional hazards regression analysis. II. Accuracy 
and precision of regression estimates. J Clin Epidemiol. 1995;48(12):1503–
1510. doi:10.1016/0895-4356(95)00048-8. 
35. 
Choice UB. Index of National Maternity Statistics. Available from:(last 
accessed 6 July 2011); 2011. 
36. 
Birthplace in England Collaborative Group. 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. 2011;343(nov23 
4):d7400–d7400. doi:10.1136/bmj.d7400. 
37. 
Lees C, Marlow N, Arabin B, Bilardo CM, Brezinka C, Derks JB, Duvekot J, 
Frusca T, Diemert A, Ferrazzi E, Ganzevoort W, Hecher K, Martinelli P, 
Ostermayer E, Papageorghiou AT, Schlembach D, Schneider KTM, 
Thilaganathan B, Todros T, van Wassenaer Leemhuis A, Valcamonico A, 
Visser GHA, Wolf H. Perinatal morbidity and mortality in early-onset fetal 

The Sono-VE Study: Assessing the acceptability and feasibility of transperineal ultrasound and developing an ultrasound based 
predictive model for labour outcome-v3 
 
Version 3 
19th February 2015 
Page 34 of 41 
growth restriction: cohort outcomes of the trial of randomized umbilical and 
fetal flow in Europe (TRUFFLE). Ultrasound in Obstetrics & Gynecology. 
2013;42(4):400–408. doi:10.1002/uog.13190. 
38.   Wilma K, Wilma M, Zar M. Psychometric aspects of the W-DEQ; a new 
questionnaire for the measurement of fear of childbirth. Journal of 
Psychosomatic Obstetrics & Gynecology 1998 19:2 , 84-97 
 

The Sono-VE Study: Assessing the acceptability and feasibility of transperineal ultrasound and developing an ultrasound based 
predictive model for labour outcome-v3 
 
Version 3 
19th February 2015 
Page 35 of 41 
12.  Appendix 
 
Sagittal Scan: 
 
 
Transverse scan: 
 
 
Figure 1 Transperineal Sagittal and Transverse application of 2D transducer. The 
sagittal scan is used to obtain views of the maternal symphysis pubis and fetal skull. 
The transducer may be rotated 180 degrees (transverse application) in order to 
visualise the cervix and head-perineum distance14. 
 
 

The Sono-VE Study: Assessing the acceptability and feasibility of transperineal ultrasound and developing an ultrasound based 
predictive model for labour outcome-v3 
 
Version 3 
19th February 2015 
Page 36 of 41 
 
  
 
 
Figure 2 Cervical dilatation assessed by 2D transperineal ultrasound during labour. 
The cervical dilatation is clearly visible at the centre with vaginal wall hyperechogenic 
laterally to the cervix. At the top of the picture is the perineum where the 
transperineal probe is placed14 
 
 
 
 

The Sono-VE Study: Assessing the acceptability and feasibility of transperineal ultrasound and developing an ultrasound based 
predictive model for labour outcome-v3 
 
Version 3 
19th February 2015 
Page 37 of 41 
 
 
Figure 3 The sonopartogram15.  
 
 
 
 
 

The Sono-VE Study: Assessing the acceptability and feasibility of transperineal ultrasound and developing an ultrasound based 
predictive model for labour outcome-v3 
 
Version 3 
19th February 2015 
Page 38 of 41 
 
 
 
 
Figure 4 The sonopartogram animation video- note we have only been able to 
provide a screenshot. (Courtesy of Mr CC Lees). 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 

The Sono-VE Study: Assessing the acceptability and feasibility of transperineal ultrasound and developing an ultrasound based 
predictive model for labour outcome-v3 
 
Version 3 
19th February 2015 
Page 39 of 41 
 
 
 
Figure 5- Study Design Overview 
 
 

The Sono-VE Study: Assessing the acceptability and feasibility of transperineal ultrasound and developing an ultrasound based 
predictive model for labour outcome-v3 
 
Version 3 
19th February 2015 
Page 40 of 41 
 
 
 
Figure 6- Gantt Chart of Study Timeline 
 
 
 
 
 
 
 

The Sono-VE Study: Assessing the acceptability and feasibility of transperineal ultrasound and developing an ultrasound based predictive model for labour outcome-v3 
 
Version 3 
19th February 2015 
Page 41 of 41 
Figure 7: Flowchart of study design 
 
The Sono-VE Study 
 
 
Non-Acute Antenatal Setting 
Patient Information Sheets will be distributed in 
the antenatal period (where possible) 
Recruitment, Screening Interview & Study Entry 
Consent Form 
Reproductive Health Interview 
Baseline Height and Weight (if not already available) 
 
 
Acceptability and Feasibility 
of Transperineal Ultrasound 
 
 
        Predictive Model 
 
Admission Ultrasound: 
-Transabdominal ultrasound scan: Position, amniotic fluid 
volume and Dopplers 
-Transperineal scan 
Thereafter:  
When vaginal assessment isdeemed necessary, repeat 
transabdominal (position) and transperineal ultrasound 
assessment 
Acute Setting 
Term nulliparous labouring women 
Screening Interview & Study Entry 
Patient Information Sheet 
Consent Form 
Reproductive Health Interview 
Pre-Study Questionnaire 
Acute Setting 
24-42 weeks gestation  
Screening Interview & Study Entry 
Patient Information Sheet 
Consent Form 
Reproductive Health Interview 
Vaginal Examination and 
Ultrasound assessment: 
Digital vaginal examination and/or speculum 
Transabdominal and transperineal scan 
Post-Study Questionnaire