Pulling forces involved with forceps delivery and its association with maternal injury during birth
| ISRCTN | ISRCTN18126471 |
|---|---|
| DOI | https://doi.org/10.1186/ISRCTN18126471 |
| ClinicalTrials.gov (NCT) | Nil known |
| Clinical Trials Information System (CTIS) | Nil known |
| Protocol serial number | 2019-275-1 |
| Sponsors | Safe Obstetrics Systems Limited, Servicio de Ginecologia y Obstetricia. Complejo Hospitalario Universitario Insular-Materno Infantil de Canarias |
| Funder | Safe Obstetrics Systems Limited (United Kingdom) |
- Submission date
- 16/08/2019
- Registration date
- 22/08/2019
- Last edited
- 22/08/2019
- Recruitment status
- No longer recruiting
- Overall study status
- Completed
- Condition category
- Pregnancy and Childbirth
Plain English summary of protocol
Background and study aims
Forceps delivery has been shown to be associated with a higher risk of injury towards the pelvic floor muscle when compared to normal vaginal delivery or vacuum delivery. The tearing of this muscle from its bony attachment is called avulsion. It’s consequences has been associated with a higher risk of pelvic organ prolapse which is the bulging of the pelvic organs, bladder and uterus, into or out of the vagina. This condition affects gravely the quality of life of many women. To date, it is not known exactly the mechanisms involved with forceps and maternal birth trauma.
The aim of this project is to study the pulling forces involved with forceps delivery and injuries to the pelvic floor muscle. Recently, the traditional forceps has been modified and has incorporated a sensor capable of recording accurately the pulling forces the birth attendant performs when assisting these deliveries. This forceps is the Pro-nata forceps.
Who can participate?
Possible participants are all women with no previous vaginal delivery that are in labour giving birth to one child and to whom an Obstetrician has indicated a forceps delivery.
What does the study involve?
The study involves recording the pulling forces during a forceps delivery in those women where the forceps has already been indicated by an Obstetrician due to possibly prolonged labour, maternal benefit, fetal malposition or possible fetal distress. In those patients that agree to participate, the Pro-nata forceps will be used instead of the traditional forceps without a sensor.
After delivery participants will be followed up 3 months after delivery where a medical history will be taken and a gynaecological examination and a transperineal ultrasound performed. The transperineal ultrasound is used to identify the integrity of the pelvic floor muscle. It is carried out with a covered abdominal ultrasound probe placed on the perineum. Ultrasound has no side-effects on the mother.
What are the possible benefits and risks of participating?
Those who decide to participate will be informed whether they have sustained major pelvic floor birth trauma. Those patients that are symptomatic after delivery will be referred to the appropriate specialist for treatment and follow up if appropriate. Also, the participants will be coached to perform correctly pelvic floor muscle exercises.
Those that decide to participants are those undergoing a forceps delivery. Participating in this study does not add any other risk than those inherent to forceps delivery such as higher rate of perineal tears, urine, gas and stool leakage among others when compared to normal vaginal delivery.
Where is the study run from?
Servicio de Ginecología y Obstetricia. Complejo Hospitalario Insular-Materno Infantil de Canarias (Gynecology and Obstetrics Service. Canary Islands Insular-Maternal and Child Hospital Complex), Gran Canaria
When is the study starting and how long is it expected to run for?
August 2019 to August 2020
Who is funding the study?
Safe Obstetrics Systems Limited (United Kingdom)
Who is the main contact?
Mr Ismael Ortega Cárdenes MD, Specialist in Obstetrics and Gynaecology
iortcar@gobiernodecanarias.org
Contact information
Scientific
Complejo Hospitalario Insular-Materno Infantil de Canarias
Av Marítima s/n
Las Palmas de Gran Canaria
35316
Spain
 ORCID ID |
0000-0003-3152-6091 |
|---|---|
| Phone | 0034928444830 |
| iortcar@gobiernodecanarias.org |
Public
Complejo Hospitalario Insular-Materno Infantil de Canarias
Av Marítima s/n
Las Palmas de Gran Canaria
35016
Spain
| ORCID ID |
0000-0003-3152-6091 |
|---|---|
| Phone | 0034928444830 |
| iortcar@gobiernodecanarias.org |
Study information
| Primary study design | Observational |
|---|---|
| Study design | Observational prospective study |
| Secondary study design | Longitudinal study |
| Study type | Participant information sheet |
| Scientific title | A prospective observational study of the traction forces required to deliver with forceps and it’s relationship to levator ani injury. |
| Study objectives | The levator ani muscle injuries associated with forceps deliveries are a result of exceeding certain traction force threshold. Thus, our objective is to study the association between the traction force of the forceps and trauma to the levator ani muscle (avulsion). Secondly, to determine the obstetrical data that are associated with increased traction force |
| Ethics approval(s) | Approved 05/07/2019, Ethics committee of University Hospital of Gran Canaria 'Dr Negrin' (Edf. Anexo al Hospital Univ. de Gran Canaria "Dr Negrín", 35019 Las Palmas de G.C., Gran Canaria), ref: 2019-275-1 |
| Health condition(s) or problem(s) studied | Levator ani muscle avulsion during forceps delivery |
| Intervention | This is a prospective study that will be carried out in a tertiary center where all the nulliparous women who undergo a forceps delivery during the study period will be included. The forceps that will be used is a metric forceps (Pro-nata), manufactured by Surgical Dynamics. This forceps device is a single-use forceps made of disposable material and contains a memory card that records the traction force exerted over time and that can be analyzed on a computer. This forceps also contains an indicator that alerts if the maximum traction has been reached. Since this threshold is unknown, it will be deactivated during the study period thus allowing forceps and traction force to continue in the same manner at this center. After forceps delivery, the memory card will be removed and stored in an envelope identified with the patient’s data and date of delivery. All singleton nulliparae with a Pro-nata forceps delivery carried out at the authors institution will be followed up at three months after delivery. All participants will undergo a 4D translabial ultrasound (TLUS) and volumes will be stored anonymously. Offline analysis of the stored 4D TLUS volumes will be analyzed at a later date blinded to all data using the software 4D view (GE Kretz Medical Ultrasound, Zipf, Austria). TLUS will be performed in a dorsal lithotomy after voiding using Voluson 730 Expert or S10 system. Stored 4D TLUS volumes will be analysed offline blinded to all data using 4D view by one of the authors. Levator trauma will be established following diagnostic criteria published previously. As well as an assessment of the presence of injury to the levator ani muscle, obstetrical data and its association to traction force will be assessed. The obstetric data will be obtained from the local electronic database (Drago). Sample size: An initial sample of 100 forceps deliveries will be considered. However, a first analysis will be performed after reaching 50 forceps deliveries and the sample size will be recalculated. |
| Intervention type | Device |
| Phase | Not Applicable |
| Drug / device / biological / vaccine name(s) | |
| Primary outcome measure(s) |
Avulsion of the levator ani muscle. Avulsion will be diagnosed when a defect is observed at the puborectalis insertion using Tomographic Ultrasound Imaging (TUI) at the level of minimal hiatal dimensions and 2.5 and 5mm slices cranially. In doubtful cases, the ‘levator urethra gap’ will be used to rate individual slices as abnormal when the distance from the urethra to the insertion of the puborectalis muscle is more than 25mm. |
| Key secondary outcome measure(s) |
Obstetric data gathered from patient records: |
| Completion date | 19/08/2020 |
Eligibility
| Participant type(s) | Patient |
|---|---|
| Age group | Adult |
| Sex | Female |
| Target sample size at registration | 100 |
| Key inclusion criteria | 1. Singleton pregnancy 2. Nulliparae 3. Forceps delivery (Pro-nata forceps) |
| Key exclusion criteria | 1. Twin deliveries 2. Breech deliveries 3. Previous vaginal delivery |
| Date of first enrolment | 22/08/2019 |
| Date of final enrolment | 21/08/2020 |
Locations
Countries of recruitment
- Spain
Study participating centre
Las Palmas de Gran Canaria
35016
Spain
Results and Publications
| Individual participant data (IPD) Intention to share | Yes |
|---|---|
| IPD sharing plan summary | Stored in repository |
| IPD sharing plan | The current data sharing plans for this study are unknown and will be available at a later date |
Study outputs
| Output type | Details | Date created | Date added | Peer reviewed? | Patient-facing? |
|---|---|---|---|---|---|
| Participant information sheet | Participant information sheet | 11/11/2025 | 11/11/2025 | No | Yes |
Editorial Notes
20/08/2019: Trial’s existence confirmed by the Ethics committee of University Hospital of Gran Canaria 'Dr Negrin'
