Labor PainNCT05512065
Changes in Velocimetric Indices of Uterine and Umbilical Arteries Before and After Combined Spinal-epidural Analgesia in Laboring Women
A study testing Ultrasound in people with Labor Pain, run by Samuel Lunenfeld Research Institute, Mount Sinai Hospital at 1 site in Canada.
Trial summary
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. Read more about this study
- Who is it for?
- Ages 18 to 50 years, women onlyHealthy volunteers can take part
- Conditions the study is for
- Labor Pain
- What is being tested?
- Ultrasound
- Type of treatment
- Medical device
- Could I receive a placebo?
- No, everyone receives an active treatment
- How many people
- 30 participants
- Where
- 1 siteCanada
- Study dates
- 14 Sep 2022to 30 Mar 2024
- Phase
- Interventional
- Are there results?
- None posted in the registry
Key requirements
Who can take part, as listed by the sponsor. Only the study team can confirm whether you are eligible, so take this list to your doctor.
- Ages 18 to 50 years
- Women only
- Healthy volunteers accepted
- Adult
Who may be able to join
- 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
Who cannot join
- Refusal to consent for the study
- Known spinal deformities
- Previous back instrumentation
- Patients with BMI>50 kg/㎡ due to anticipated technical challenges in Doppler studies
Trial locations and contacts
1 site in 1 country.
About this study
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.
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.
- Conditions
- Labor Pain
- Being tested
- Ultrasound
- Keywords
- combined spinal epidural (CSE), fetal bradycardia, ultrasound, velocimetric index
- Medical subject headings
- Labor Pain
What participants receive
What participants receive. In a randomised study each person is assigned to one group by chance.
UltrasoundDevice
Ultrasound scan of the right and left uterine arteries and umbilical artery.
| Study group | Role | What they receive |
|---|---|---|
| Ultrasound | Experimental | Ultrasound will be used to measure velocimetric indices of both right and left uterine arteries and umbilical artery. Receives: Device: Ultrasound |
What is being measured
The primary outcome is the main question the study is designed to answer.
Uterine artery velocimetric index - systolic/diastolic ratio (S/D) at baseline
Uterine artery velocimetric index - systolic/diastolic ratio (S/D) will be measured at baseline (prior to combined spinal epidural).
Measured: 5 minutes
Uterine artery velocimetric index - systolic/diastolic ratio (S/D) at 10 minutes
Uterine artery velocimetric index - systolic/diastolic ratio (S/D) will be measured 10 minutes after combined spinal epidural
Measured: 5 minutes
Uterine artery velocimetric index - systolic/diastolic ratio (S/D) at 30 minutes
Uterine artery velocimetric index - systolic/diastolic ratio (S/D) will be measured 30 minutes after combined spinal epidural
Measured: 5 minutes
Uterine artery velocimetric index - pulsatility index (PI) at baseline
Uterine artery velocimetric index - pulsatility index (PI) will be measured at baseline (prior to combined spinal epidural).
Measured: 5 minutes
Uterine artery velocimetric index - pulsatility index (PI) at 10 minutes
Uterine artery velocimetric index - pulsatility index (PI) will be measured 10 minutes after combined spinal epidural
Measured: 5 minutes
Uterine artery velocimetric index - pulsatility index (PI) at 30 minutes
Uterine artery velocimetric index - pulsatility index (PI) will be measured 30 minutes after combined spinal epidural
Measured: 5 minutes
Uterine artery velocimetric index - resistance index (RI) at baseline
Uterine artery velocimetric index - resistance index (PI) will be measured at baseline (prior to combined spinal epidural).
Measured: 5 minutes
Uterine artery velocimetric index - resistance index (RI) at 10 minutes
Uterine artery velocimetric index - resistance index (PI) will be measured 10 minutes after combined spinal epidural
Measured: 5 minutes
Uterine artery velocimetric index - resistance index (RI) at 30 minutes
Uterine artery velocimetric index - resistance index (PI) will be measured 30 minutes after combined spinal epidural
Measured: 5 minutes
Umbilical artery velocimetric index - systolic/diastolic ratio (S/D) at baseline
Umbilical artery velocimetric index - systolic/diastolic ratio (S/D) will be measured at baseline (prior to combined spinal epidural).
Measured: 5 minutes
Umbilical artery velocimetric index - systolic/diastolic ratio (S/D) at 10 minutes
Umbilical artery velocimetric index - systolic/diastolic ratio (S/D) will be measured 10 minutes after combined spinal epidural
Measured: 5 minutes
Umbilical artery velocimetric index - systolic/diastolic ratio (S/D) at 30 minutes
Umbilical artery velocimetric index - systolic/diastolic ratio (S/D) will be measured 30 minutes after combined spinal epidural
Measured: 5 minutes
Umbilical artery velocimetric index - pulsatility index (PI) at baseline
Umbilical artery velocimetric index - pulsatility index (PI) will be measured at baseline (prior to combined spinal epidural).
Measured: 5 minutes
Umbilical artery velocimetric index - pulsatility index (PI) at 10 minutes
Umbilical artery velocimetric index - pulsatility index (PI) will be measured 10 minutes after combined spinal epidural
Measured: 5 minutes
Umbilical artery velocimetric index - pulsatility index (PI) at 30 minutes
Umbilical artery velocimetric index - pulsatility index (PI) will be measured 30 minutes after combined spinal epidural
Measured: 5 minutes
Umbilical artery velocimetric index - resistance index (PI) at baseline
Umbilical artery velocimetric index - resistance index (PI) will be measured at baseline (prior to combined spinal epidural).
Measured: 5 minutes
Umbilical artery velocimetric index - resistance index (PI) at 10 minutes
Umbilical artery velocimetric index - resistance index (PI) will be measured 10 minutes after combined spinal epidural
Measured: 5 minutes
Umbilical artery velocimetric index - resistance index (PI) at 30 minutes
Umbilical artery velocimetric index - resistance index (PI) will be measured 30 minutes after combined spinal epidural
Measured: 5 minutes
Secondary outcomes (19)
Pain score at baseline - questionnaire
Pain score - verbal numeric rating scale (0-10) prior to combined spinal epidural
Measured: 1 minute
Pain score at 10 min - questionnaire
Pain score - verbal numeric rating scale (0-10) at 10 min after combined spinal epidural
Measured: 1 minute
Pain score at 30 min - questionnaire
Pain score - verbal numeric rating scale (0-10) at 30 min after combined spinal epidural
Measured: 1 minute
Hypotension: systolic blood pressure less than 80% of baseline
Systolic blood pressure < 80% of baseline, monitored q5 for 30 minutes following combined spinal epidural
Measured: 30 minutes
Hypertension: systolic blood pressure greater than 120% of baseline
Systolic blood pressure > 120% of baseline, monitored q5 for 30 minutes following combined spinal epidural
Measured: 30 minutes
Bradycardia: heart rate less than 70% of baseline
Heart rate < 70% of baseline or a heart rate < 50bpm, monitored q5 for 30 minutes following combined spinal epidural
Measured: 30 minutes
Desaturation: oxygen level <95%
Oxygen level <95%, monitored q5 for 30 minutes following combined spinal epidural
Measured: 30 minutes
Sensory block level at 10 minutes
Sensory block level at 10 minutes following combined spinal epidural
Measured: 10 minutes
Sensory block level at 30 minutes
Sensory block level at 30 minutes following combined spinal epidural
Measured: 30 minutes
Duration of labour
Onset of labour until delivery of the placenta
Measured: up to 24 hours
Type of delivery
Type of delivery will be recorded: vaginal, cesarean section, instrumental delivery
Measured: up to 24 hours
Presence of hypertonic uterine contractions
Presence of hypertonic uterine contractions as noted by the nursing or obstetric team.
Measured: up to 24 hours
fetal heart rate at baseline
fetal heart rate at baseline, prior to combined spinal epidural
Measured: 5 minutes
fetal heart rate q5 min up to 30 minutes
fetal heart rate q5 min up to 30 minutes following combined spinal epidural
Measured: 30 minutes
presence of fetal bradycardia - questionnaire
presence of fetal bradycardia (fetal heart rate <110)
Measured: up to 24 hours
presence of fetal tachycardia - questionnaire
presence of fetal tachycardia (fetal heart rate >160)
Measured: up to 24 hours
Neonatal weight
Neonatal weight measured after delivery in grams
Measured: 2 minutes
Apgar score at 1 minute
Apgar score at 1 minute
Measured: 1 minute
Apgar score at 5 minutes
Apgar score at 5 minutes
Measured: 5 minute2
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted23 Aug 2022
- Study start14 Sep 2022
- Primary completion30 Mar 2024
- Study completion30 Mar 2024
Resources
- Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
- Publications (1)Papers the sponsor has linked to this study.
- Other trials for Labor PainStudies of the same condition, open and under way.
- What the trial phases meanHow a treatment moves from first tests in people to approval.
More details
For doctors and researchers: how the study is designed, who runs it, and its registry IDs.
Study design
- Study type
- Interventional
- Phase
- Phase N/A
- Primary purpose
- Diagnosis
- Allocation
- Not applicable
- Intervention model
- Single group
- Masking
- None (open label)
- Enrolment
- 30 participants (actual)
Sponsor and investigators
- Lead sponsor
- Samuel Lunenfeld Research Institute, Mount Sinai Hospital
- Sponsor type
- University, hospital or other
- Responsible party
- Sponsor
- Investigators
- Mrinalini Balki, MD, Principal investigator, MOUNT SINAI HOSPITAL
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT05512065
- Sponsor's protocol ID
- 22-04
- Status last verified
- Oct 2023
- First submitted
- 19 Aug 2022
- Last updated
- 24 Oct 2024
- Results posted
- No
- Data monitoring committee
- No
- FDA-regulated drug
- No
- FDA-regulated device
- No
- Individual data sharing
- No
Publications
Vargas J, Hirano A, Arzola C, Hobson SR, Kunpalin Y, Downey K, Balki M. Changes in velocimetric indices of uterine and umbilical arteries before and after combined spinal epidural analgesia in laboring women: a prospective cohort study. Int J Obstet Anesth. 2025 Nov;64:104770. doi: 10.1016/j.ijoa.2025.104770. Epub 2025 Sep 5.
PubMed 40945309
Study at a glance
From the registry record, last updated by the sponsor on 24 Oct 2024. Recruitment status is as the sponsor reported it: confirm with the study team.
- Official title
- Changes in Velocimetric Indices of Uterine and Umbilical Arteries Before and After Combined Spinal-epidural Analgesia in Laboring Women
- ClinicalTrials.gov ID
- NCT05512065
- Acronym / sponsor ID
- 22-04
- Conditions
- Labor Pain
- Keywords
- combined spinal epidural (CSE), fetal bradycardia, ultrasound, velocimetric index
- Study type
- Interventional
- Recruitment status
- Completed
- Enrolment
- 30 participants (actual)
- Lead sponsor
- Samuel Lunenfeld Research Institute, Mount Sinai HospitalUniversity, hospital or other
- Study start
- 14 Sep 2022 (actual)
- Primary completion
- 30 Mar 2024 (actual)
- Study completion
- 30 Mar 2024 (actual)
- First posted
- 23 Aug 2022 (actual)
- Results
- Not posted in the source record
Clinical summary
The research question as the sponsor registered it. This describes what the study plans to test, not what it found.
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.
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.
Study design
- Primary purpose
- Diagnosis
- Allocation
- Not applicable
- Intervention model
- Single group
- Masking
- None (open label)
- Number of arms
- 1
| Arm | Type | Receives |
|---|---|---|
| Ultrasound | Experimental | Device: UltrasoundUltrasound will be used to measure velocimetric indices of both right and left uterine arteries and umbilical artery. |
Who may qualify
- Ages
- 18 to 50 years
- Sex
- Female only
- Healthy volunteers
- Accepted
- Age groups
- Adult
Key inclusion criteria (6 listed)
- Written informed consent
- Term pregnant patients requesting labor analgesia
- Singleton pregnancy
- Term pregnant patients in active labor
- ASA<4
Key exclusion criteria (4 listed)
- Refusal to consent for the study
- Known spinal deformities
- Previous back instrumentation
- Patients with BMI>50 kg/㎡ due to anticipated technical challenges in Doppler studies
Eligibility is decided by the study team after screening; this overview does not establish that a patient qualifies. Full inclusion and exclusion criteria.
Interventions
| Intervention | Type | Arms |
|---|---|---|
| UltrasoundUltrasound scan of the right and left uterine arteries and umbilical artery. | Device | Ultrasound |
Primary outcome
Uterine artery velocimetric index - systolic/diastolic ratio (S/D) at baseline
Time frame: 5 minutes
Uterine artery velocimetric index - systolic/diastolic ratio (S/D) will be measured at baseline (prior to combined spinal epidural).
Uterine artery velocimetric index - systolic/diastolic ratio (S/D) at 10 minutes
Time frame: 5 minutes
Uterine artery velocimetric index - systolic/diastolic ratio (S/D) will be measured 10 minutes after combined spinal epidural
Uterine artery velocimetric index - systolic/diastolic ratio (S/D) at 30 minutes
Time frame: 5 minutes
Uterine artery velocimetric index - systolic/diastolic ratio (S/D) will be measured 30 minutes after combined spinal epidural
Uterine artery velocimetric index - pulsatility index (PI) at baseline
Time frame: 5 minutes
Uterine artery velocimetric index - pulsatility index (PI) will be measured at baseline (prior to combined spinal epidural).
Uterine artery velocimetric index - pulsatility index (PI) at 10 minutes
Time frame: 5 minutes
Uterine artery velocimetric index - pulsatility index (PI) will be measured 10 minutes after combined spinal epidural
Uterine artery velocimetric index - pulsatility index (PI) at 30 minutes
Time frame: 5 minutes
Uterine artery velocimetric index - pulsatility index (PI) will be measured 30 minutes after combined spinal epidural
Uterine artery velocimetric index - resistance index (RI) at baseline
Time frame: 5 minutes
Uterine artery velocimetric index - resistance index (PI) will be measured at baseline (prior to combined spinal epidural).
Uterine artery velocimetric index - resistance index (RI) at 10 minutes
Time frame: 5 minutes
Uterine artery velocimetric index - resistance index (PI) will be measured 10 minutes after combined spinal epidural
Uterine artery velocimetric index - resistance index (RI) at 30 minutes
Time frame: 5 minutes
Uterine artery velocimetric index - resistance index (PI) will be measured 30 minutes after combined spinal epidural
Umbilical artery velocimetric index - systolic/diastolic ratio (S/D) at baseline
Time frame: 5 minutes
Umbilical artery velocimetric index - systolic/diastolic ratio (S/D) will be measured at baseline (prior to combined spinal epidural).
Umbilical artery velocimetric index - systolic/diastolic ratio (S/D) at 10 minutes
Time frame: 5 minutes
Umbilical artery velocimetric index - systolic/diastolic ratio (S/D) will be measured 10 minutes after combined spinal epidural
Umbilical artery velocimetric index - systolic/diastolic ratio (S/D) at 30 minutes
Time frame: 5 minutes
Umbilical artery velocimetric index - systolic/diastolic ratio (S/D) will be measured 30 minutes after combined spinal epidural
Umbilical artery velocimetric index - pulsatility index (PI) at baseline
Time frame: 5 minutes
Umbilical artery velocimetric index - pulsatility index (PI) will be measured at baseline (prior to combined spinal epidural).
Umbilical artery velocimetric index - pulsatility index (PI) at 10 minutes
Time frame: 5 minutes
Umbilical artery velocimetric index - pulsatility index (PI) will be measured 10 minutes after combined spinal epidural
Umbilical artery velocimetric index - pulsatility index (PI) at 30 minutes
Time frame: 5 minutes
Umbilical artery velocimetric index - pulsatility index (PI) will be measured 30 minutes after combined spinal epidural
Umbilical artery velocimetric index - resistance index (PI) at baseline
Time frame: 5 minutes
Umbilical artery velocimetric index - resistance index (PI) will be measured at baseline (prior to combined spinal epidural).
Umbilical artery velocimetric index - resistance index (PI) at 10 minutes
Time frame: 5 minutes
Umbilical artery velocimetric index - resistance index (PI) will be measured 10 minutes after combined spinal epidural
Umbilical artery velocimetric index - resistance index (PI) at 30 minutes
Time frame: 5 minutes
Umbilical artery velocimetric index - resistance index (PI) will be measured 30 minutes after combined spinal epidural
19 secondary outcomes
Pain score at baseline - questionnaire
Time frame: 1 minute
Pain score at 10 min - questionnaire
Time frame: 1 minute
Pain score at 30 min - questionnaire
Time frame: 1 minute
Hypotension: systolic blood pressure less than 80% of baseline
Time frame: 30 minutes
Hypertension: systolic blood pressure greater than 120% of baseline
Time frame: 30 minutes
Bradycardia: heart rate less than 70% of baseline
Time frame: 30 minutes
Desaturation: oxygen level <95%
Time frame: 30 minutes
Sensory block level at 10 minutes
Time frame: 10 minutes
Sensory block level at 30 minutes
Time frame: 30 minutes
Duration of labour
Time frame: up to 24 hours
Type of delivery
Time frame: up to 24 hours
Presence of hypertonic uterine contractions
Time frame: up to 24 hours
fetal heart rate at baseline
Time frame: 5 minutes
fetal heart rate q5 min up to 30 minutes
Time frame: 30 minutes
presence of fetal bradycardia - questionnaire
Time frame: up to 24 hours
presence of fetal tachycardia - questionnaire
Time frame: up to 24 hours
Neonatal weight
Time frame: 2 minutes
Apgar score at 1 minute
Time frame: 1 minute
Apgar score at 5 minutes
Time frame: 5 minute2
Results and safety
The study is completed, but results are not available in the source record. That does not mean the treatment did or did not work.
Research links
- Official record on ClinicalTrials.govLast updated by the sponsor 24 Oct 2024.
- Derived from this study: PubMed 40945309Vargas J, Hirano A, Arzola C, Hobson SR, Kunpalin Y, Downey K, Balki M. Changes in velocimetric indices of uterine and umbilical arteries before and after combined spinal epidural analgesia in laboring women: a prospective cohort study. Int J Obstet Anesth. 2025 Nov;64:104770. doi: 10.1016/j.ijoa.2025.104770. Epub 2025 Sep 5.
- Individual participant dataSharing planned: No
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Referral and contact
AzTrials does not enrol participants or take referrals. Contact the study team or a site listed below; they decide who can take part. This study is not recruiting at the moment.
Mrinalini Balki, MD principal investigator
MOUNT SINAI HOSPITAL
1 site in 1 country: see every site and its status.
Questions about this trial
What is this clinical trial studying?
A study testing Ultrasound in people with Labor Pain, run by Samuel Lunenfeld Research Institute, Mount Sinai Hospital at 1 site in Canada.
The full registered description is in the About this study section and the official record.
Who may be eligible to take part?
The sponsor lists 6 inclusion and 4 exclusion criteria. Eligibility is decided by the study team after screening, so read the full criteria and contact a listed site.
Is this clinical trial currently recruiting?
The record says: finished, as of the sponsor's last update on 24 Oct 2024. Status can change between updates, so confirm with the study contact before making plans.
Where is the study taking place?
The record lists 1 site in Canada. Whether a site is taking part right now should be confirmed with that site. See every site.
What are the possible benefits and risks?
They depend on the study and the treatment, and no study can promise a benefit. The study team explains the known risks during informed consent, before anyone joins; the record itself does not list them.
Are results available for this study?
The study is completed, but results are not available in the source record. That does not mean the treatment did or did not work.
How can a doctor refer a patient or contact the research team?
The record lists no contact. The official record names the sponsor, who can be asked directly. AzTrials does not enrol participants or take referrals.
What does the primary outcome measure?
Uterine artery velocimetric index - systolic/diastolic ratio (S/D) at baseline (time frame: 5 minutes). The study lists 18 primary outcomes in all. It is what the study was designed to measure, not a finding.
Where can I read the original study information?
On the ClinicalTrials.gov record for NCT05512065, which also lists 1 linked publication.
Does a listing mean the treatment is approved or proven to work?
No. A listing means the study is registered. It does not show that the treatment is safe, works, or is approved by a regulator.
How often is this information updated?
AzTrials copies changed records from ClinicalTrials.gov every night and reloads the whole registry every week. The sponsor last updated this record on 24 Oct 2024.