Clinical trial NCT05306756: Fetal Scalp Stimulation Versus Fetal Blood Sampling in Labour
Official title: Fetal Scalp Stimulation (FSS) Versus Fetal Blood Sampling (FBS) to Assess Fetal Wellbeing in Labour - a Multi-centre Randomised Controlled Trial.
Study type: INTERVENTIONAL
Overall status: TERMINATED
Phase: NA
Conditions: Intrapartum Fetal Distress
Keywords: randomised controlled trial
fetal blood sampling
fetal scalp stimulation
cardiotocography
caesarean section
Lead sponsor: University of Dublin, Trinity College
Sponsor class: OTHER
Collaborators: name: University College Cork
name: University of Limerick
name: Royal College of Surgeons, Ireland
name: National University of Ireland, Galway, Ireland
name: Health Research Board, Ireland
name: Health Research Board - Trials Methodology Research Network
First posted: 2022-04-01
Enrollment: 40
Sex: FEMALE
Minimum age (years): 18
Standard ages: ADULT
OLDER_ADULT
Accepts healthy volunteers: no
Allocation: RANDOMIZED
Intervention model: PARALLEL
Intervention model description: Patients in labor with CTG abnormalities that warrant second-line testing of fetal wellbeing - randomized to digital fetal scalp stimulation (dFSS) versus fetal blood sampling (FBS)
Primary purpose: DIAGNOSTIC

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.

Eligibility criteria: 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

Primary outcomes:
measure: Caesarean section (CS)
timeFrame: at birth
Secondary outcomes:
measure: Caesarean section , primary indication fetal concerns
timeFrame: at birth
measure: Caesarean section, primary indication poor progress
timeFrame: at birth
measure: Caesarean section, failed attempt at assisted vaginal birth
timeFrame: at birth
measure: Assisted vaginal birth (AVB) (all cases)
timeFrame: at birth
measure: Assisted vaginal birth, primary indication fetal concerns
timeFrame: at birth
measure: Assisted vaginal birth, primary indication poor progress
timeFrame: at birth
measure: Spontaneous Vaginal Birth (SVB)
timeFrame: at birth
measure: Decision Delivery Interval (DDI) for emergency CS >30 minutes
timeFrame: during labour up until time of birth
measure: Decision Delivery Interval (DDI) for AVB >15 minutes
timeFrame: during labour up until time of birth
measure: Perinatal death
timeFrame: up to 7 days of age
measure: Late perinatal death
timeFrame: 8-28 days of life
measure: Apgar score at 5 minutes <7
timeFrame: age 5 minutes
measure: pH umbilical artery <7.00 or Base Excess artery <-12.0
timeFrame: immediately after birth
measure: Admission to neonatal unit (NNU)
timeFrame: from birth up until 28 days
measure: Neonatal encephalopathy (as defined by authors)
timeFrame: from birth up until 28 days
measure: Therapeutic hypothermia
timeFrame: indicated within 6 hours of birth
measure: Abnormal neurological examination prior to discharge
timeFrame: at time of hospital discharge, assessed up to 28 days after birth
measure: FBS related injury/complication to baby (as reported on neonatal examination)
timeFrame: at birth or with first 7 days of life
measure: Major obstetric haemorrhage >1000mL
timeFrame: up to 24 hours after birth
measure: Obstetric Anal Sphincter Injury (OASI - all degrees)
timeFrame: at birth
measure: Referral to perinatal mental health services
timeFrame: from birth up to six weeks after birth
measure: Maternal acceptability of procedure (defined by questionnaire)
timeFrame: from birth up to 7 days after birth
measure: Number of second-line tests (dFSS or FBS)
timeFrame: during labour up until birth
measure: Number of inconclusive/uninterpretable dFSS procedures
timeFrame: during labour up until birth
measure: Number of failed FBS procedures
timeFrame: during labour up until birth
Other outcomes:
Locations:
city: Dublin
country: Ireland
facility: Coombe Women & Infants University Hospital
Study officials:
affiliation: Trinity College, University of Dublin
name: Deirdre J Murphy, MD
role: PRINCIPAL_INVESTIGATOR
References:
citation: Hughes O, Murphy DJ. Comparing second-line tests to assess fetal wellbeing in Labor: a feasibility study and pilot randomized controlled trial. J Matern Fetal Neonatal Med. 2022 Jan;35(1):91-99. doi: 10.1080/14767058.2020.1712704. Epub 2020 Jan 12.
citation: Murphy DJ, Shahabuddin Y, Yambasu S, O'Donoghue K, Devane D, Cotter A, Gaffney G, Burke LA, Molloy EJ, Boland F. Digital fetal scalp stimulation (dFSS) versus fetal blood sampling (FBS) to assess fetal wellbeing in labour-a multi-centre randomised controlled trial: Fetal Intrapartum Randomised Scalp Stimulation Trial (FIRSST NCT05306756). Trials. 2022 Oct 4;23(1):848. doi: 10.1186/s13063-022-06794-9.