Fetal Scalp Stimulation (FSS) Versus Fetal Blood Sampling (FBS) to Assess Fetal Wellbeing in Labour - a Multi-centre Randomised Controlled Trial.
Trial Snapshot
- Phase
- Not Applicable
- Status
- Terminated
- Enrollment
- 40
- Locations
- 2
- Primary Endpoint
- Caesarean section (CS)
Study Overview
Brief Summary
Pregnant women have routine monitoring of the baby's heart rate when in labour. Women with complicated pregnancies require continuous monitoring using an electronic recorder called a CTG. The CTG produces a paper based recording which is interpreted by the midwife as showing normal, suspicious or abnormal features of the baby's heart rate. Babies quite commonly demonstrate abnormal features from time to time during the course of labour. In some cases the abnormal features are of sufficient concern to warrant delivery by emergency caesarean section. In most of these cases the baby is born in good condition and the question arises whether the caesarean section was unnecessary. In order to reduce the chance of an unnecessary caesarean section additional "second-line" tests can be offered. One such test is where a small drop of blood is taken from the baby's scalp. This test involves an internal examination with an instrument to visualise the baby's head and a small scratch to the baby's scalp. The blood is tested for acid which is an indicator of whether or not the baby is receiving enough oxygen. The test is called a fetal blood sample or FBS. An alternative test is where the doctor or midwife performs a vaginal examination with two fingers and gently rubs the baby's scalp in an attempt to cause an increase in the baby's heart rate. This is a healthy response suggesting that the baby is receiving enough oxygen. The test is called digital fetal scalp stimulation or dFSS. These two "second-line" tests have never been compared in a properly conducted head-to-head comparison. This study aims to compare dFSS and FBS in a large clinical trial completed within four of Ireland's largest maternity hospitals. This trial will generate important evidence of direct relevance to clinical care and patient outcomes.
Detailed Description
Continuous electronic fetal heart rate recording with cardiotocography (CTG) is a standard approach to monitoring fetal wellbeing in labour and is recommended for high-risk pregnancies. The aim is to identify fetal compromise early and intervene in order to reduce serious adverse events such as cerebral palsy and perinatal death. CTG abnormalities are relatively common and can lead to the decision to deliver by emergency caesarean section. In most cases the fetus is subsequently found to have been compensating for the stress of labour and is not actually compromised. Fetal blood sampling (FBS) is a second-line invasive test that provides information on the acid-base status of the fetus, reflecting hypoxia. It is used to provide either reassurance that labour can continue, or more objective evidence that delivery needs to be expedited. Clinical guidelines in the United Kingdom and Ireland have treated FBS as a gold standard test. Recent studies have questioned the validity and reliability of FBS, and also the logistic challenges of achieving a result in a timely manner. Fetal scalp stimulation (dFSS) by digital rubbing is an alternative less invasive test of fetal wellbeing in labour and is recommended in preference to FBS in US guidelines. This research aims to compare digital FSS and FBS in women with term singleton pregnancies and an abnormal intrapartum CTG, where additional information on fetal wellbeing is required. A multi-centre randomised controlled trial will be conducted. The clinical outcomes of interest will include caesarean section, assisted vaginal birth, low Apgar scores, cord blood acidosis, and admission to the neonatal unit. This trial will generate important evidence of direct relevance to clinical care and patient outcomes.
Study Design
- Study Type
- Interventional
- Allocation
- Randomized
- Intervention Model
- Parallel
- Primary Purpose
- Diagnostic
- Masking
- Double (Investigator, Outcomes Assessor)
Masking Description
The primary and perinatal secondary outcomes will be recorded from the computerised delivery record without knowledge of the allocation.
The principal investigator will play no role in the care of the patient or assessment of outcomes.
Eligibility Criteria
- Ages
- 18 Years to — (Adult, Older Adult)
- Sex
- Female
- Accepts Healthy Volunteers
- No
Inclusion Criteria
- •Nulliparous women
- •Singleton pregnancy
- •Cephalic presentation
- •Gestational age 37+0 weeks or greater
- •Abnormal CTG that requires second-line testing (FBS or dFSS)
Exclusion Criteria
- •Contraindication to FBS
- •Limited understanding of English
- •At the discretion of the responsible obstetrician in cases where there is urgency
Outcomes
Primary Outcomes
Caesarean section (CS)
Time Frame: at birth
All caesarean sections will be in labour in the context of an abnormal CTG
Secondary Outcomes
- Spontaneous Vaginal Birth (SVB)(at birth)
- Apgar score at 5 minutes <7(age 5 minutes)
- Decision Delivery Interval (DDI) for AVB >15 minutes(during labour up until time of birth)
- Assisted vaginal birth, primary indication poor progress(at birth)
- Abnormal neurological examination prior to discharge(at time of hospital discharge, assessed up to 28 days after birth)
- Major obstetric haemorrhage >1000mL(up to 24 hours after birth)
- Obstetric Anal Sphincter Injury (OASI - all degrees)(at birth)
- Perinatal death(up to 7 days of age)
- Caesarean section, primary indication poor progress(at birth)
- Caesarean section, failed attempt at assisted vaginal birth(at birth)
- Assisted vaginal birth, primary indication fetal concerns(at birth)
- Late perinatal death(8-28 days of life)
- pH umbilical artery <7.00 or Base Excess artery <-12.0(immediately after birth)
- Admission to neonatal unit (NNU)(from birth up until 28 days)
- Therapeutic hypothermia(indicated within 6 hours of birth)
- Caesarean section , primary indication fetal concerns(at birth)
- Assisted vaginal birth (AVB) (all cases)(at birth)
- Decision Delivery Interval (DDI) for emergency CS >30 minutes(during labour up until time of birth)
- Number of inconclusive/uninterpretable dFSS procedures(during labour up until birth)
- Neonatal encephalopathy (as defined by authors)(from birth up until 28 days)
- Maternal acceptability of procedure (defined by questionnaire)(from birth up to 7 days after birth)
- FBS related injury/complication to baby (as reported on neonatal examination)(at birth or with first 7 days of life)
- Referral to perinatal mental health services(from birth up to six weeks after birth)
- Number of second-line tests (dFSS or FBS)(during labour up until birth)
- Number of failed FBS procedures(during labour up until birth)
Investigators
Deirdre J Murphy
Professor of Obstetrics
University of Dublin, Trinity College