STOP-OHSS
Research type
Research Study
Full title
STOP-OHSS (Shaping and Trialling Outpatient Protocols for Ovarian HyperStimulation Syndrome): A randomised controlled trial to assess the clinical and cost-effectiveness of active management of Ovarian HyperStimulation Syndrome.
IRAS ID
298619
Contact name
Mostafa Metwally
Contact email
Sponsor organisation
SHEFFIELD TEACHING HOSPITALS NHS FOUNDATION TRUST
ISRCTN Number
ISRCTN71978064
Duration of Study in the UK
4 years, 11 months, 30 days
Research summary
Ovarian hyperstimulation syndrome (OHSS) is a condition that can affect women undergoing fertility treatment. OHSS is caused by the medication taken to increase egg production during ovulation induction or In Vitro Fertilisation (IVF). Too many eggs can develop, and the ovaries can become large and painful. It can affect both women who are pregnant and women who have not become pregnant but are still recovering from the effects of this medication given during their fertility treatment.
Currently, OHSS is managed conservatively. Doctors/fertility teams monitor the condition and if the symptoms worsen, admit the woman to hospital for intensive monitoring or treatment.
The aim of the STOP-OHSS trial is to establish the clinical and cost-effectiveness, safety and acceptability of outpatient paracentesis as an earlier active management for women with moderate or severe OHSS.
STOP-OHSS is a pragmatic, parallel open-label, multi-centre, superiority, adaptive, group sequential, confirmatory RCT with an internal pilot to assess feasibility aspects. Participants will be individually allocated 1:1 to receive outpatient paracentesis or conservative management. A qualitative study will be conducted during the internal pilot phase to facilitate the feasibility of conducting the RCT by identifying problems so that solutions can be instigated rapidly.
A total of 224 women with moderate or severe OHSS will be randomised to the trial. A 0% withdrawal rate is assumed as the primary outcome is short term, occurring at 28 days, and can be collected directly from patient notes (consent will be obtained). Approximately 20 private and NHS Fertility Units are expected to take part from England and Scotland.
Summary of study results:
Ovarian hyperstimulation syndrome (OHSS) can affect women having fertility treatment. It makes the ovaries become large and painful. ‘Early’ OHSS is caused by the medication used to increase egg production, and usually happens within 7 days. ‘Late’ OHSS is caused by a hormone naturally produced during pregnancy, and usually happens over 10 days after the other drugs are given. Mild cases get better quickly, but moderate or severe cases can result in delays to fertility treatment, prolonged hospital care, and in rare cases can be life threatening.
Patients sometimes receive paracentesis if admitted to hospital for treatment. This is a procedure where a needle is inserted through the vagina or abdomen to drain fluid. The aim of this trial (STOP-OHSS (Shaping and Trialling Outpatient Protocols for Ovarian HyperStimulation Syndrome) was to understand whether acting earlier by carrying out the same paracentesis procedure but in an outpatient setting, and including additional monitoring, can stop symptoms getting worse and prevent women being admitted to hospital.
We first asked patients and doctors about their experiences with OHSS, then experts agreed on how to carry out the study. Participants were then randomly assigned to receive either outpatient paracentesis with extra monitoring, or standard care. Unfortunately, recruitment was difficult, causing the study to be stopped early after recruiting only eight patients. We could not answer our main question about whether the new treatment is better, but it did seem to be safe and feasible to carry out. We also conducted a survey after the main study closed, which revealed that many fertility clinics changed how they do things because of the COVID-19 pandemic. They started using methods that might reduce the chance of OHSS happening in the first place.
We have submitted reports to provide more details on these findings. Publications will be listed on our trial webpage https://gbr01.safelinks.protection.outlook.com/?url=http%3A%2F%2Fwww.sheffield.ac.uk%2Fctru%2Fcurrent-trials%2Fstop-ohss&data=05%7C02%7Clondonsoutheast.rec%40hra.nhs.uk%7C2180987c94cb435f13d808dcd89afbc8%7C8e1f0acad87d4f20939e36243d574267%7C0%7C0%7C638623407367461890%7CUnknown%7CTWFpbGZsb3d8eyJWIjoiMC4wLjAwMDAiLCJQIjoiV2luMzIiLCJBTiI6Ik1haWwiLCJXVCI6Mn0%3D%7C0%7C%7C%7C&sdata=XManDgspWbGEfyf6riuaeHRuHJK9gvI%2BmvvJjKymAD4%3D&reserved=0.
This project was sponsored by Sheffield Teaching Hospitals, and funded by the National Institute for Health and Care Research (NIHR) Health Technology Assessment programme (NIHR128137). The views expressed are those of the author(s) and not necessarily those of the NIHR or the Department of Health and Social Care.
We would like to express our sincere gratitude to the participants who took part in this trial.
REC name
London - South East Research Ethics Committee
REC reference
22/LO/0015
Date of REC Opinion
25 Feb 2022
REC opinion
Further Information Favourable Opinion