Full Dilatation Caesarean Section, Impacted Fetal Head
Conditions
Keywords
Impacted fetal head, Caesarean section, Full dilatation caesarean section, Tydeman Tube, Fetal Pillow
Brief summary
A single centre prospective observational comparison trial to compare the Tydeman Tube and Fetal Pillow, to aid delivery of the impacted fetal head at full dilatation caesarean section, and to evaluate the use of the Tydeman Tube at 7-9cm.
Detailed description
An impacted fetal head is a common complication encountered in 11% of all emergency caesarean sections and 65% of those performed at full dilatation. A recent UK Obstetric Surveillance Survey (UKOSS) highlighted significant maternal and neonatal complications secondary to an impacted fetal head, with 3% of babies dying or suffering a severe injury, and 6.1% of mother's requiring admission to intensive care, emphasizing the need to evaluate techniques and new devices to aid delivery. NHS resolution's early notification scheme implicated an impacted fetal head as a contributing factor in 9% of all severe neonatal brain injuries in 2019. There is no consensus amongst clinicians on the best management of an impacted fetal head, and with exponentially rising rates of intrapartum caesarean sections, improved management tools are urgently required. This study will compare maternal and neonatal outcomes using two devices to aid delivery of an impacted fetal head at full dilatation caesarean section (FDCS)- the Tydeman Tube, a new UK Conformity Assessed (UKCA) and European Conformity (CE) marked device, and the Fetal Pillow, an existing CE marked device used commonly in clinical practice. There will be a separate observational sub study evaluating the use of the Tydeman Tube for managing an impacted fetal head at 7-9cm dilated. The study will also explore the acceptability of both devices to women and clinicians using postnatal questionnaires. Participants will be all women requiring a full dilatation caesarean section who meet eligibility criteria. The study will be run in two consecutive arms - firstly, obstetricians and midwives will be trained to use the Fetal Pillow. The Fetal Pillow will then be introduced into clinical practice for 3-6 months. Following this the Fetal Pillow will be removed from clinical practice. Midwives and Obstetricians will then be trained to use the Tydeman Tube, which will be introduced into clinical practice for a further 3-6 months. During the Tydeman Tube arm of the trial, women undergoing caesarean section at 7-9cm who are found to have an impacted fetal head unexpectedly at the time of caesarean section are eligible for the observational sub study. If the operating surgeon believes the Tydeman Tube is required for the clinical situation then it may be used. The trial is a prospective observational comparison trial with an additional observational sub study. The results of this study will be used to improve understanding on the best management techniques for an impacted fetal head.
Interventions
DEVICEFetal Pillow
The Fetal Pillow is a CE marked single use sterile device. It is used in Caesarean sections performed at full dilatation. The Fetal Pillow is designed to atraumatically elevate the fetal head out of the pelvis before a caesarean section begins, making the delivery safer, easier and less traumatic. It comprises of a base plate, which is placed posteriorly in the vagina between the fetal head and the vaginal wall. It is then slowly inflated with 180mls of water via a thin tube, which aims to elevate the fetal head. It is removed at the end of the caesarean section. Some evidence for the Fetal Pillow suggests it can reduce maternal and fetal complications from FDCS by enabling elevation of a deeply engaged head, with some studies demonstrating a reduction in uterine incision extensions, lower estimated blood lossand fewer neonatal intensinve care (NICU)admissions. However evidence is conflicting and newer randomised control trials suggest no difference in outcome when using the device.
DEVICETydeman Tube
The Tydeman Tube is a UKCA/CE marked single use sterile device designed to aid delivery of an impacted fetal head at caesarean section. It consists of a semi-rigid wide bore silicone tube and flexible silicone cup.The tube is inserted into the vagina before or during caesarean section where an impacted fetal head is anticipated or encountered. It can be used from 7-10cm dilated. The cup fits against the baby's head. The tube is held by the assistant and used to elevate the head by pushing upwards. This disimpacts the head from the pelvis and brings it towards the surgeon's hand to enable delivery. The cup dissipates the force applied evenly over a wide area of the head which is intended to prevent fetal trauma. Once the surgeon has gained access below the head, the wide bore tube and design of the cup allows air to enter below the head during delivery to limit suction effect. Once the baby is delivered the Tydeman Tube is removed from the vagina.
Sponsors
Guy's and St Thomas' NHS Foundation Trust
King's College London
Study design
Allocation
NON_RANDOMIZED
Intervention model
SEQUENTIAL
Primary purpose
TREATMENT
Masking
NONE
Intervention model description
Sequential arms with 2 different treatments. 3-6 months using first device (Fetal Pillow), 3-6 months using second device (Tydeman Tube).
Eligibility
Sex/Gender
FEMALE
Age
16 Years to No maximum
Healthy volunteers
No
Inclusion criteria
* Undergoing caesarean section at full dilataion for fetal pillow arm, or caesarean section at 7 or more centimetres dilated for the tydeman tube arm * Singleton pregnancy * Cephalic presentation
Exclusion criteria
* Allergy to silicone rubber * Major congenital abnormalities * Major anomaly of the fetal head (i.e. large encephalocele) * Intrauterine death * Suspected chorioamnionitis * Active genital infection inc. Herpes Simplex Virus * Cervical dilatation \<10cm for fetal pillow arm and \<7cm for tydeman tube arm * Gestational age \<37 weeks * non-cephalic presentation
Design outcomes
Primary
| Measure | Time frame | Description |
|---|---|---|
| Time from uterine incision to delivery | 4 weeks | Seconds |
Secondary
| Measure | Time frame | Description |
|---|---|---|
| Uterine incision to closure time | 4 weeks | Seconds |
| Estimated blood loss | 4 weeks | mLs |
| Requirement of blood products | 4 weeks | Yes/No |
| Volume of blood products | 4 weeks | Dependent on type of product |
| Presence of uterine angle extensions | 4 weeks | Yes/No |
| Presence of visceral injury | 4 weeks | Yes/No - visceral injuries may include ureter, cervix, bladder, bowel |
| Need for hysterectomy | 4 weeks | Yes/No |
| Presence of genital tract trauma | 4 weeks | Yes/No - genital tract trauma may include lacerations and haematomas |
| Admission to HDU/ITU | 4 weeks | Yes/No |
| Maternal death | 4 weeks | Yes/No |
| Length of stay | 4 weeks | Days |
| Wound infection | 4 weeks | Yes/No |
| Endometritis | 4 weeks | Yes/No |
| Change in maternal haemoglobin (Hb) | 4 weeks | Difference in measured Hb before caesarean and after caesarean |
| Presence of birth trauma to the neonate | 4 weeks | Yes/No - birth trauma may include intracranial haemorrhage, skull fracture, other fracture, facial nerve injury (bruising/facial nerve palsy/other nerve injury) |
| Apgar score | 4 weeks | Routine test taken of the newborn infant based on Appearance (colour), Pulse (heart rate), Grimace (reflexes), Activity (muscle tone) and Respiration (breathing) at 5 and 10 minutes - scored from 0-10 with lower scores indicating poor condition and need for assessment/intervention |
| Resuscitation required | 4 weeks | Yes/No |
| Admission to special care baby unit (SCBU) or neonatal intensive care unit (NICU) | 4 weeks | Yes/No |
| Length of stay in higher care | 4 weeks | Days |
| Arterial cord pH measurement | 4 weeks | Measures the acidity of a newborn's blood from the umbilical artery, reflecting fetal oxygenation and metabolic state at birth, with normal ranges around 7.18-7.38, lower values (\<7.0) can signal distress, risk of neurological issues and often require neonatal observation |
| Diagnosis of hypoxic-ischaemic encephalopathy (HIE) | 4 weeks | Yes/No and Grading (1,2,3) HIE is a brain injury from lack of oxygen and/or blood flow to the brain around the time of birth, affecting newborns. It is associated with potential long-term disability including cerebral palsy or developmental delay, and in severe cases death. Symptoms include seizures, poor feeding and altered alternates. It is graded as mild (Grade 1), moderate (Grade 2) and severe (Grade 3) |
| Perinatal death | 4 weeks | Yes/No |
| Neonatal feeding | 4 weeks | — |
| Evaluation of Fetal Pillow / Tydeman tube using Lickert scale questionnaires (clinician) | 4 weeks | Acceptability, ease of use, perception of impacted head and perception of ease of delivery will be assessed using Lickert scale questionnaires where participants will be asked to rate their level of agreement or feeling on a symmetrical scale, form one extreme to another (i.e. 'strongly disagree' to 'strongly agree') |
| Acceptability of Fetal Pillow / Tydeman Tube using Lickert scan questionnaires (maternal) | 4 weeks | Patients perception of the acceptability of the two devices will be assessed using Lickert scale questionnaires where participants will be asked to rate their level of agreement or feeling on a symmetrical scale, form one extreme to another (i.e. 'strongly disagree' to 'strongly agree') |
Contacts
CONTACTLaura van der Krogt, MBBS
CONTACTAndrew Shennan, MD
PRINCIPAL_INVESTIGATORAndrew Shennan, MD
King's College London / Guy's and St Thomas'
Outcome results
None listed