The lactate in pregnancy study
| ISRCTN | ISRCTN38095366 |
|---|---|
| DOI | https://doi.org/10.1186/ISRCTN38095366 |
| IRAS number | 332026 |
| Secondary identifying numbers | UoL001792, IRAS 332026 |
- Submission date
- 16/08/2023
- Registration date
- 12/09/2023
- Last edited
- 24/04/2025
- Recruitment status
- No longer recruiting
- Overall study status
- Ongoing
- Condition category
- Pregnancy and Childbirth
Plain English Summary
Background and study aims
Lactate is an important marker which is produced naturally by the body during exercise. It increases when a person is unwell, for example, with a severe infection. It is currently used during pregnancy if doctors suspect a bad infection or if a woman/birthing person has lost a lot of blood around the time of birth. However, the blood level of lactate may be difficult to understand during labour as labour is itself an exercise, and so can probably raise this level. This is why it is important to understand more about lactate levels in pregnant women/birthing people. Currently, lactate can only be measured through blood tests, which means it is difficult to get a clear understanding of normal lactate levels during labour. Imperial College London has developed a new patch to measure lactate. It works by using a sensor placed on the surface of the skin. Similar methods are used to monitor blood sugar levels in diabetic mothers, and this is seen as comfortable to wear by women/birthing people. The patch is painless and does not involve any blood testing. The patch can continuously measure the lactate levels in your skin and send the information to a computer. The patch has been shown to be effective and well-tolerated in a recent study of non-pregnant individuals. The first part of this study aims to use the patch in healthy pregnant women/birthing people to measure the lactate produced during, and after a period of gentle exercise and compare this with the normal ways of measuring lactate (i.e. blood tests) and understand their experience of wearing it, this study will last for 3 hours. If this works, the study will move to the second part to investigate the best place to wear the patch (study 2), if the patch works for 6 and 12 hours (study 3), and also to understand if the patch can be stored in fridge (study 4) and continue to work several months later.
Who can participate?
Study 1: Healthy pregnant women with no existing health conditions or pregnancy complications who are able to exercise for 30 minutes with normal fetal movements on the day of participation.
Study 2-4: Healthy non-pregnant volunteers
What does the study involve?
Study 1: The researchers will place the patch on the participant's arm by pressing it gently on the skin and fixing it with a bandage. They will also put a drip (cannula) into their vein to take samples of blood during the study. Once set up, participants sit and relax for 30-60 minutes and the researchers take two blood samples from the cannula during this time. Then participants walk on the spot/cycle/step for 30 minutes as fast as they feel is comfortable. During this time, blood will be sampled every 5 minutes. After this the participants rest. The study will end about an hour after the start of exercising. The drip and patch will be removed and participants will be asked to fill out a short questionnaire. They will be asked for a photograph of the skin where the patch has been placed.
Study 2: similar to study 1; however, the participant wears the device in 2 places at the same time.
Study 3: similar to study 1, except participants will be asked to exercise at the beginning and end of the 6 or 12-hour time period.
Study 4: Similar to study 2, except it will take place at different durations after the device is made and sterilised.
What are the possible benefits and risks of participating?
All procedures and equipment used in this study have been shown to be safe in previous studies. The researchers do not expect any significant side effects during or after the study.
For the patch, the main possible side effects are skin irritation or discomfort. It has been used before for 24 hours without pain or discomfort. A drip will be placed in the arm to take blood during the study. This might result in bruising of the skin although it will not cause any other problems – the bruising typically resolves in less than 1 week.
The exercise will be done by walking on the spot/stepping onto a step/cycling. The total length of exercise is 30 minutes. Participants can stop if they feel unwell, unusual or have period-like pain.
Where is the study run from?
The study is run by University of Liverpool Researchers physically located in the University of Liverpool research facility at the Harris Centre for Women’s Health Research (UK)
When is the study starting and how long is it expected to run for?
June 2023 to December 2025
Who is funding the Study?
The Wellcome-University of Liverpool Institutional Translational Partnership (ITPA) Translational Research Access Programme (TRAP) (UK)
Who is the main contact?
Carol Kingdon, nimble@liverpool.ac.uk
Contact information
Principal Investigator
Centre for Women’s Health Research
Department of Women’s and Children’s Health
University of Liverpool
Liverpool Women’s Hospital
Crown Street
Liverpool
L8 7SS
United Kingdom
 ORCID ID |
0000-0003-0352-2106 |
|---|---|
| Phone | +44 (0)151795 9562 |
| abi.merriel@liverpool.ac.uk |
Scientific
Centre for Women’s Health Research
Department of Women’s and Children’s Health
University of Liverpool
Liverpool Women’s Hospital
Crown Street
LIverpool
L8 7SS
United Kingdom
| Phone | +44 (0)151 795 9562 |
|---|---|
| abi.merriel@liverpool.ac.uk |
Public
Centre for Women’s Health Research
Department of Women’s and Children’s Health
University of Liverpool
Liverpool Women’s Hospital
Crown Street
Liverpool
L8 7SS
United Kingdom
| Phone | +44 (0)151 795 9562 |
|---|---|
| nimble@liverpool.ac.uk |
Study information
| Study design | Proof of concept study |
|---|---|
| Primary study design | Observational |
| Secondary study design | Proof of concept study |
| Study setting(s) | University/medical school/dental school |
| Study type | Other |
| Participant information sheet | Not available in web format, please use the contact details to request a participant information sheet |
| Scientific title | Minimally-invasive biosensor monitoring of lactate in healthy pregnancies: a proof of concept study |
| Study acronym | LIP |
| Study hypothesis | Proof of concept study for continuously measuring lactate in healthy pregnant women. |
| Ethics approval(s) |
Approved 15/08/2023, West of Scotland REC 4 (Research Ethics, Ward 11 Dykebar Hospital, Paisley, PA2 7DE, United Kingdom; +44 (0)1413140213; WoSREC4@ggc.scot.nhs.uk), ref: 23/WS/0121 |
| Condition | Pregnancy |
| Intervention | Continuous measurement of lactate levels using a microneedle biosensor compared to blood lactate levels to prove the concept for using the device during pregnancy. The researchers will place the patch on the participant's arm by pressing it gently on the skin and fixing it with a bandage. They will also put a drip (cannula) into their vein to take samples of blood during the study. Once set up, participants sit and relax for 30-60 minutes and the researchers take two blood samples from the cannula during this time. Then participants walk on the spot/cycle/step for 30 minutes as fast as they feel is comfortable. During this time, blood will be sampled every 5 minutes. After this the participants rest. The study will end about an hour after the start of exercising. The drip and patch will be removed and participants will be asked to fill out a short questionnaire. They will be asked for a photograph of the skin where the patch has been placed. |
| Intervention type | Device |
| Pharmaceutical study type(s) | Not Applicable |
| Phase | Phase 0 |
| Drug / device / biological / vaccine name(s) | Minimally-invasive lactate biosensor |
| Primary outcome measure | Current primary outcome measures as of 23/04/2025: 1. Continuous lactate measurement using the LIP sensor throughout the duration of the study 2. Venous lactate samples measured using a colourimetric assay at baseline, throughout the duration of the exercise and in the post-exercise rest period Previous primary outcome measures: 1. Continuous lactate measurement using the LIP sensor throughout the 3-hour duration of the study 2. Venous lactate samples measured using a colourimetric assay at baseline, throughout the duration of the exercise and in the post-exercise rest period |
| Secondary outcome measures | Feedback on the experience of wearing the device, measured using a questionnaire immediately after the device is removed |
| Overall study start date | 01/06/2023 |
| Overall study end date | 31/12/2025 |
Eligibility
| Participant type(s) | Healthy volunteer |
|---|---|
| Age group | Adult |
| Lower age limit | 18 Years |
| Upper age limit | 55 Years |
| Sex | Female |
| Target number of participants | 10 |
| Participant inclusion criteria | Current participant inclusion criteria as of 23/04/2025: Study 1: 1. Consenting pregnant adults ≥18 years old 2. Healthy with no previously diagnosed medical condition from a medical practitioner 3. Report no pregnancy complications 4. Can be taking prophylactic drugs in pregnancy for example aspirin for low PAPP-A and folic acid and other pregnancy vitamins 5. Report they are able to exercise gently for 30 minutes and do similar exercise routinely 6. Normal fetal movements on the day of participation Study 2: 1. Consenting adults ≥ 18 years old 2. Healthy with no previously diagnosed medical condition from a medical practitioner 3. Report they are able to exercise for 60 minutes, and do similar exercise routinely Previous participant inclusion criteria: 1. Consenting pregnant adults ≥18 years old 2. Healthy with no previously diagnosed medical condition from a medical practitioner 3. Report no pregnancy complications 4. Can be taking prophylactic drugs in pregnancy for example aspirin for low PAPP-A and folic acid and other pregnancy vitamins 5. Report they are able to exercise gently for 30 minutes and do similar exercise routinely 6. Normal fetal movements on the day of participation |
| Participant exclusion criteria | 1. Active inflammatory skin condition such as eczema or dermatitis 2. Active soft tissue infection or infection at any site 3. Known hypersensitivity to any microneedle component/cannula dressing or plasters 4. Presence of any implantable electronic devices such as a pacemaker or stimulators |
| Recruitment start date | 01/10/2023 |
| Recruitment end date | 31/10/2023 |
Locations
Countries of recruitment
- England
- United Kingdom
Study participating centres
Department of Women’s and Children’s Health
University of Liverpool
Liverpool Women’s Hospital
Crown Street
Liverpool
L8 7SS
United Kingdom
Crown Street
Liverpool
L8 7SS
United Kingdom
Sponsor information
University/education
Clinical Directorate
4th Floor Thompson Yates Building
Faculty of Health and Life Sciences
Liverpool
L69 3GB
England
United Kingdom
| Phone | +44 (0)7717863747 |
|---|---|
| sponsor@liverpool.ac.uk | |
| Website | http://www.liv.ac.uk/ |
"ROR" |
https://ror.org/04xs57h96 |
Funders
Funder type
Research organisation
No information available
Results and Publications
| Intention to publish date | 01/01/2025 |
|---|---|
| Individual participant data (IPD) Intention to share | No |
| IPD sharing plan summary | Data sharing statement to be made available at a later date |
| Publication and dissemination plan | The researchers plan to produce a peer-reviewed publication and share the findings at conferences. |
| IPD sharing plan | The data sharing plans for the current study are unknown and will be made available at a later date |
Editorial Notes
23/04/2025: The following changes were made:
1. The overall study end date was changed from 31/12/2024 to 31/12/2025.
2. The primary outcome measure and participant inclusion criteria were updated.
10/09/2024: The following changes were made to the trial record:
1. The overall end date was changed from 31/10/2023 to 31/12/2024.
2. The intention to publish date was changed from 01/02/2024 to 01/01/2025.
3. The plain English summary was updated to reflect these changes.
29/08/2023: Study's existence confirmed by the Health Research Authority.
