IntroductionAlthough ovarian hyperstimulation syndrome (OHSS) is a common complication primarily seen in patients undergoing in vitro fertilisation-embryo transfer, there is no recognised effective treatment to manage it, especially for pregnant patients. As an alternative non-pharmacological treatment, acupuncture presents itself as a promising, safe and effective intervention for those suffering from OHSS. Despite its potential, there is a noticeable absence of randomised controlled trials providing solid evidence on the efficacy of acupuncture in the management of pregnancy with OHSS. Therefore, the primary objective of this study is to conduct an initial investigation into the efficacy of acupuncture in pregnant patients with OHSS, hoping to contribute valuable insights from a medical-scientific perspective.Methods and analysisThis is a three-arm, single-blind, parallel-design, randomised controlled clinical trial. A total of 384 patients will be enrolled and randomised in a ratio of 1:1:1 into acupuncture group (MA group), sham acupuncture group (SA group) and control group (C group) for a 20-day treatment period. The primary outcomes include 24-hour urine output, amount of ascites shown on ultrasound, abdominal circumference, degree of abdominal distension and chest tightness. The secondary outcomes are weight, ovarian size, rate of ascites drainage by tube placement and serum hCG. Besides, the study will consider changes in blood counts and hormonal levels as additional outcomes.Ethics and disseminationThis study received authorisation from the Institutional Review Board of the Sixth Affiliated Hospital of Sun Yat-sen University on 4 February 2024 (Approval No. 2024ZSLYFEC-084). Study findings will be disseminated through presentations at scientific conferences or publications in peer-reviewed journals.Trial registration numberChinese Clinical Trial Registry ChiCTR2400081751.