Long-term effects of bariatric surgery in women with Polycystic Ovary Syndrome (PCOS), obesity and irregular or absent menstrual periods
| ISRCTN | ISRCTN16272246 |
|---|---|
| DOI | https://doi.org/10.1186/ISRCTN16272246 |
| ClinicalTrials.gov (NCT) | Nil known |
| Clinical Trials Information System (CTIS) | Nil known |
| Integrated Research Application System (IRAS) | Nil known |
| Protocol serial number | Nil known |
| Sponsor | NIHR Imperial Biomedical Research Centre |
| Funder | NIHR Imperial Biomedical Research Centre |
- Submission date
- 05/07/2025
- Registration date
- 20/10/2025
- Last edited
- 20/10/2025
- Recruitment status
- Recruiting
- Overall study status
- Ongoing
- Condition category
- Nutritional, Metabolic, Endocrine
Plain English summary of protocol
Background and study aims
Infertility affects around 1 in 6 couples worldwide. In about 30% of cases, the cause is related to the female partner. One common cause is Polycystic Ovary Syndrome (PCOS), which can lead to irregular or absent periods and problems with ovulation. Obesity can make these symptoms worse. A previous study called the BAMBINI trial showed that weight loss surgery (bariatric surgery) helped women with PCOS and obesity have more regular ovulatory cycles compared to standard medical care. This new follow-up study will look at the long-term effects of that surgery on fertility, metabolism, and quality of life.
Who can participate?
Women who took part in the original BAMBINI clinical trial (https://www.isrctn.com/ISRCTN16668711) may be invited to join this follow-up study.
What does the study involve?
This is an observational study, which means there are no treatments or interventions. Participants will be asked to attend follow-up visits where researchers will collect information about their health, fertility, and well-being over time.
What are the possible benefits and risks of participating?
The main benefit is helping researchers understand how bariatric surgery affects the body in the long term, especially in women with PCOS. There are no significant risks, as this is not a treatment study and no new procedures will be done.
Where is the study run from?
NIHR Imperial Clinical Research Facility at Hammersmith Hospital in London (UK)
When is the study starting and how long is it expected to run for?
April 2025 to September 2026
Who is funding the study?
NIHR Imperial Biomedical Research Centre (UK)
Who is the main contact?
Dr Suhaniya Samarasinghe, suhaniya.samarasinghe@nhs.net
Contact information
Public, Scientific, Principal investigator
MRC Laboratory of Medical Sciences
Imperial London Hammersmith Campus
London
W12 0HS
United Kingdom
 ORCID ID |
0000-0001-8111-4218 |
|---|---|
| Phone | +44 207 594 5444 |
| suhaniya.samarasinghe@nhs.net |
Study information
| Primary study design | Observational |
|---|---|
| Study design | Single centre observational study |
| Secondary study design | Longitudinal study |
| Study type | Participant information sheet |
| Scientific title | Bariatric surgery vs. Medical care for obesity and polycystic ovarian syndrome related infertility: Long-term follow-up of the BAMBINI randomised-controlled clinical trial |
| Study acronym | BAMBINI 2.0 |
| Study objectives | To investigate the long-term safety and efficacy of obesity surgery in women with PCOS, obesity and oligomenorrhoea or amenorrhoea |
| Ethics approval(s) |
Not yet submitted, London-Dulwich REC (2 Redman Place, Stratford, London, E20 1JQ, United Kingdom; +44 207 104 8109; dulwich.rec@hra.nhs.uk) |
| Health condition(s) or problem(s) studied | Long-term effects of bariatric surgery in women with Polycystic Ovary Syndrome, obesity and oligomenorrhoea or amenorrhoea. |
| Intervention | This study will invite all participants who took part in the BAMBINI clinical trial (ISRCTN16668711) and received their randomly allocated intervention to attend for a single visit. At this visit, they will have undergo a detailed medical questionnaire, anthropometric measurements, blood tests for reproductive and metabolic hormones, urine pregnancy test, optional adipose tissue biopsy and genetic blood test. |
| Intervention type | Other |
| Primary outcome measure(s) |
Number of patient-reported menstrual cycles in the last 12 months |
| Key secondary outcome measure(s) |
Metabolic outcomes: |
| Completion date | 01/09/2026 |
Eligibility
| Participant type(s) | Other |
|---|---|
| Age group | Adult |
| Sex | Female |
| Target sample size at registration | 76 |
| Key inclusion criteria | Participants from the BAMBINI clinical trial who received their randomly allocated trial intervention. As part of the initial trial, participants gave their consent to be contacted for potential participation in other research studies. |
| Key exclusion criteria | Patients who did not receive their randomly allocated intervention as part of the original BAMBINI clinical trial. |
| Date of first enrolment | 01/09/2025 |
| Date of final enrolment | 02/05/2026 |
Locations
Countries of recruitment
- United Kingdom
- England
Study participating centre
Du Cane Rd
Shepherd's Bush
London
W12 0HS
United Kingdom
Results and Publications
| Individual participant data (IPD) Intention to share | Yes |
|---|---|
| IPD sharing plan summary | Published as a supplement to the results publication |
| IPD sharing plan | All data generated or analysed during this study will be included in the subsequent results publication. |
Study outputs
| Output type | Details | Date created | Date added | Peer reviewed? | Patient-facing? |
|---|---|---|---|---|---|
| Participant information sheet | Participant information sheet | 11/11/2025 | 11/11/2025 | No | Yes |
Editorial Notes
20/10/2025: Trial's existence confirmed by the National Institute for Health and Care Research (NIHR) (UK).
