Ultrasound checks blood flow in labouring women before and after spinal-epidural pain relief
Uses ultrasound to measure blood flow in the uterus and baby's umbilical artery during labor.
Key facts
- Who runs it
- Samuel Lunenfeld Research Institute, Mount Sinai Hospital
- Where
- Toronto, CanadaSee the site
- Trial code
- Registry title
- Changes in Velocimetric Indices of Uterine and Umbilical Arteries Before and After Combined Spinal-epidural Analgesia in Laboring Women (PART II)
- Status
- Recruiting
- People taking part
- 54 people, planned
- Started
- 30 Oct 2024
- Planned end
- Jan 2026
- Type of study
- Interventional, 2 groups
- Treatments tested
- Ultrasound
- Record updated
- 11 July 2025
Who can take part
AI summary
From the trial's eligibility criteria. Machine-read from the registry text on this page, so it can be wrong. The registry text below and the trial team decide who can take part.
The trial is looking for pregnant women at full term, in active labor, who ask for pain relief during labor and carry one baby.
- Age
- 18 Years to 50 Years
- Sex
- Female only
- Disease stage
- Full-term pregnancy with one baby, in active labor. Women with or without high blood pressure disorders of pregnancy can join.
- Biomarker or test result
- No sign of birth defects in the baby, no sign of fetal distress and no slowing of the baby's heartbeat before the spinal-epidural pain relief.
Main reasons for not taking part
- Refusal to give consent for the study
- Known spinal deformities
- Previous back surgery with implanted hardware
- BMI above 50 kg/㎡, because Doppler ultrasound would be hard to do
- ASA class 4 or higher
This trial only enrols pregnant participants. The registry sentence this rests on: Term pregnant patients requesting labor analgesia
The registry criteria, word for word
Show all 11 criteriaShow less
Who can take part
- Written informed consent
- Term pregnant patients requesting labor analgesia
- Singleton pregnancy
- Term pregnant patients in active labor
- ASA<4
- No evidence of fetal congenital anomalies, fetal compromise or fetal decelerations prior to CSE
- Patients with and without diagnosed hypertensive disorders of pregnancy
Who cannot take part
- Previous back instrumentation
- Refusal to consent for the study
- Known spinal deformities
- Patients with BMI>50 kg/㎡ due to anticipated technical challenges in Doppler studies
Check if you might fit
Answer for yourself. This is not a decision: only the study team can say whether you can take part.
- Are you between 18 and 50 years old?
Where in Canada
- Mount Sinai HospitalToronto, CanadaContact: Mrinalini Balki, MDTaking people
About the trial
What the trial wants to find out
Combined spinal-epidural (CSE) for labor analgesia has been used for many years and is practiced commonly at our institution, especially when the patient requests immediate pain relief. CSE is not only beneficial for its faster onset of analgesia, but also it is favorable in relation to the need for rescue analgesia, urinary retention, and rate of instrumental delivery compared to the traditional epidural. Despite its beneficial effects, there is a risk of about 15-30% of developing abnormal fetal heart rate following CSE. This is self-resolving with minimal or no intervention. Although the cause of fetal bradycardia is not fully elucidated, variations in uterine artery blood flow after epidural analgesia are thought to be due to the interaction of numerous events related to blockade of sympathetic innervations, fluid administration, maternal hypotension, uterine vascular effects of sympathetic block, fluctuations in circulating catecholamines, and possibly the effect of opioids. Similar mechanism is thought to be a cause of fetal bradycardia after the CSE with its faster onset and superior block.
Read full original descriptionShow less
Maternal or fetal circulation during labor can be assessed using continuous-wave Doppler ultrasound to monitor maternal uterine artery (UtA) and fetal umbilical artery (UmA) velocity waveforms to detect changes in blood flow. The velocimetry indices mentioned above have been often used to assess the changes in the blood flow before and after the induction of epidural analgesia during labor in several studies. Although there are some studies regarding the effect of labor epidural analgesia using velocimetry indices, but there is currently no published study evaluating velocimetry indices of uterine and umbilical arteries before and after the induction of CSE. Thus, the aim of this study is to investigate the impact of CSE to maternal and fetal blood flow to evaluate the relationships.
The investigators hypothesize that both uterine artery and umbilical artery blood flow are reduced after the induction of CSE, which may be responsible for the occurrence of fetal bradycardia.
The 2 groups in the trial
- Ultrasound - patients without hypertensive disorders of pregnancyTreatment being tested
Ultrasound will be used to measure velocimetric index of the umbilical artery.
Treatment: Ultrasound
- Ultrasound - patients with diagnosed hypertensive disorders of pregnancyTreatment being tested
Ultrasound will be used to measure velocimetric index of the umbilical artery.
Treatment: Ultrasound
Questions to ask the study team
- How often do I need to come in, and for how long each time?
- Are travel costs paid?
- Can I keep my own doctor?
- What happens if I want to stop?
Contact the study team: see the registry record → Contacts and Locations
Print a page for my doctorData and sources
- Registry record
- Listed on ClinicalTrials.gov.
- Official title
- Changes in Velocimetric Indices of Uterine and Umbilical Arteries Before and After Combined Spinal-epidural Analgesia in Laboring Women (PART I and PART II)
- Plain-language title
- Ultrasound checks blood flow in labouring women before and after spinal-epidural pain reliefGenerated from the registry record. The registry title is the official one.
- AI summary
- From the trial's eligibility criteria. Read by machine on 12 November 2026.
- Fit questions
- Built from NCT06655675, who can take part
- Record updated
- 11 July 2025