Guideline sources The following summarized guidelines for the evaluation and management of ovarian hyperstimulation syndrome (OHSS) are prepared by our editorial team based on guidelines from the Society of Obstetricians and Gynaecologists of Canada (SOGC 2017; 2014), the Royal College of Obstetricians and Gynaecologists (RCOG 2016), and the American Society for Reproductive Medicine (ASRM 2016). 1 2 3 4 Guidelines 1. Classification and risk stratification Prediction of ovarian hyperstimulation syndrome: recognize that PCOS, elevated anti- M llerian hormone values (> 3.4 ng/mL), peak estradiol levels (> 3,500 pg/mL), multifollicular development (antral follicle count > 24, development of 25 follicles), and a high number of oocytes retrieved ( 24) increase the risk of OHSS. B https://web.pathway.md/diseases/recN605IEcZt9Ht8Q 1/6 6/30/23, 1:25 AM Ovarian hyperstimulation syndrome Pathway Classification: As per SOGC 2017 guidelines, classify the severity of OHSS as mild, moderate, severe, or critical. B As per RCOG 2016 guidelines, classify the severity of OHSS according to a standardized classification scheme. B 2. Diagnostic investigations Initial evaluation: assess patients presenting with symptoms suggestive of OHSS face-to-face by a clinician if there is any doubt about the diagnosis or if the severity is likely to be greater than mild. B Show 3 more 3. Medical management Setting of care: As per SOGC 2017 guidelines, manage patients with mild or moderate OHSS in an outpatient setting. Ensure that the patient is capable of adhering to clinical instructions and there is a system in place to assess her status every 1-2 days when offering outpatient management for more severe OHSS. B Show 2 more As per RCOG 2016 guidelines, manage patients with mild or moderate and selected patients with severe OHSS in an outpatient setting. B Show 5 more Fluid resuscitation: As per SOGC 2017 guidelines, initiate IV hydration with a crystalloid solution to prevent hemoconcentration and provide adequate end-organ perfusion. Administer an alternate colloid solution if end-organ perfusion is not maintained with a crystalloid solution. B As per ASRM 2016 guidelines, initiate fluid resuscitation as part of the management of patients with OHSS. B As per RCOG 2016 guidelines: Initiate fluid replacement by the oral route guided by thirst as the most physiological approach to correcting intravascular dehydration. B Consider obtaining invasive monitoring, managed with anesthetic input, in patients with persistent hemoconcentration despite volume replacement with IV colloids. C Diuretics: avoid using diuretics as they further deplete intravascular volume. Consider administering diuretics in a multidisciplinary setting if oliguria persists despite adequate fluid replacement and drainage of ascites. D Thromboprophylaxis: https://web.pathway.md/diseases/recN605IEcZt9Ht8Q 2/6 6/30/23, 1:25 AM Ovarian hyperstimulation syndrome Pathway As per SOGC 2017 guidelines, consider administering prophylactic doses of anticoagulants in patients with severe OHSS. C As per ASRM 2016 guidelines, initiate fluid resuscitation as part of the management of patients with OHSS. B As per RCOG 2016 guidelines, initiate thromboprophylaxis with LMWH in patients with severe OHSS being managed on an outpatient basis, with a duration of treatment based on risk factors and whether or not conception occurs. B Show 3 more Pain management: As per SOGC 2017 guidelines: Administer acetaminophen and/or opioid analgesics for pain relief in hospitalized patients. B Do not use NSAIDs with antiplatelet properties. D As per RCOG 2016 guidelines, provide pain management in patients with OHSS. B Show 2 more Antiemetics: consider administering antiemetics in patients with OHSS. C GnRH antagonists: insufficient evidence to support the use of gonadotrophin-releasing hormone antagonists for the treatment of patients with OHSS. I Dopamine agonists: insufficient evidence to support the use of dopamine agonists for the treatment of patients with OHSS. I Plasma expanders: insufficient evidence to support the use of plasma expanders alone for the treatment of patients with OHSS. I 4. Therapeutic procedures Paracentesis: As per SOGC 2017 guidelines, perform paracentesis in hospitalized patients with tense ascites to alleviate the condition. B As per ASRM 2016 guidelines, consider performing therapeutic paracentesis in patients with OHSS with a large amount of ascites. C As per RCOG 2016 guidelines, consider performing US-guided paracentesis of ascitic fluid in an outpatient setting. C Show 2 more Culdocentesis: As per SOGC 2017 guidelines, consider performing outpatient culdocentesis for the prevention of disease progression in moderate or severe OHSS. C As per ASRM 2016 guidelines, consider culdocentesis in patients with OHSS in whom a large amount of ascites is present. C https://web.pathway.md/diseases/recN605IEcZt9Ht8Q 3/6 6/30/23, 1:25 AM Ovarian hyperstimulation syndrome Pathway 5. Surgical interventions Indications for surgery: perform surgery by an experienced surgeon only in patients with a coincident condition, such as adnexal torsion, ovarian rupture, or ectopic pregnancy. B 6. Patient education General counseling: As per SOGC 2017 guidelines: Counsel each female of her personal risk for OHSS when prescribing gonadotropins. B Counsel females to contact a physician or a member of the team within the hospital with relevant experience, if needed, when prescribing gonadotropins in areas where patients do not have ready access to physicians familiar with the diagnosis and management of OHSS. B As per RCOG 2016 guidelines: Be aware of the possibility of OHSS in all patients undergoing fertility treatment and counsel patients accordingly. Provide verbal and written information, including a 24-hour contact telephone number, concerning OHSS to all patients undergoing fertility treatment. B Counsel patients that pregnancies complicated by OHSS may be at increased risk of preeclampsia and preterm delivery. B 7. Preventative measures Ovarian stimulation protocols: As per ASRM 2016 guidelines, consider using ovarian stimulation protocols to reduce the risk of OHSS in patients with PCOS, elevated anti-M llerian hormone levels, and increased antral follicle count. C Show 4 more As per SOGC 2014 guidelines, use GnRH antagonist stimulation protocols in patients at high risk for OHSS. Consider administering a GnRH agonist as a substitute for hCG to trigger final oocyte maturation in order to reduce the risk of severe OHSS in patients on GnRH antagonist protocols with a very robust ovarian stimulation response. B Show 3 more Luteal phase support: administer progesterone, rather than hCG, for luteal phase support. A Embryo transfer: perform elective single embryo transfer in patients at high risk for OHSS. B Embryo cryopreservation: consider offering cryopreservation of embryos to prevent OHSS. C Metformin: As per ASRM 2016 guidelines, consider initiating metformin to prevent OHSS in patients with PCOS. B https://web.pathway.md/diseases/recN605IEcZt9Ht8Q 4/6 6/30/23, 1:25 AM Ovarian hyperstimulation syndrome Pathway As per SOGC 2014 guidelines, consider initiating metformin in patients with PCOS undergoing IVF to reduce the risk of OHSS. B Aspirin: consider initiating aspirin to prevent OHSS. B Dopamine agonists: consider initiating dopamine agonists for several days, starting at the time of hCG trigger, to reduce the incidence of OHSS. B Plasma expanders: As per ASRM 2016 guidelines, insufficient evidence to support the use of albumin to reduce the risk of OHSS. I As per SOGC 2014 guidelines, do not use albumin or other plasma expanders at the time of egg retrieval to prevent OHSS. D Calcium: recognize that there is fair evidence that IV calcium lowers the risk of OHSS. B 8. Follow-up and surveillance Serial clinical assessment: assess patients admitted with OHSS at least once daily. Obtain more frequent assessments in patients with critical OHSS and in patients with complications. B 9. Quality improvement Hopsital regulations: Establish local protocols for the assessment and management of OHSS in all acute units where patients with suspected OHSS are likely to present and ensure access to appropriately skilled clinicians with experience in the management of this condition. B Ensure close liaison and coordination between centers providing fertility treatment and acute units where patients with OHSS may present. B Clinical findings Symptoms Past medical history Abdominal pain Controlled ovarian stimulation Bloating DVT Diarrhea PCOS Nausea Previous episodes of ovarian hyperstimulation syndrome Shortness of breath Vomiting Vascular exam Weight gain Peripheral edema Vital signs Genitourinary exam Hypotension https://web.pathway.md/diseases/recN605IEcZt9Ht8Q 5/6 6/30/23, 1:25 AM Ovarian hyperstimulation syndrome Pathway Tachycardia urine output Abdominal exam Integument exam Abdominal distension Dehydration Ascites Imaging findings Gynecologic exam Hemoperitoneum Ovarian tenderness Large number of antral follicles Vulvar swelling Pericardial effusion Pleural effusion Lab findings Pulmonary edema Hyperkalemia Hypoalbuminemia Hyponatremia anti-M llerian hormone hCG serum ALP serum ALT serum AST serum CRP serum D-dimer serum TBIL serum estradiol serum fibrinogen serum gamma- glutamyltransferase References 1. Shmorgun D, Claman P. No-268 The Diagnosis and Management of Ovarian Hyperstimulation Syndrome. J Obstet Gynaecol Can. 2017 Nov;39 11):e479-e486. Open 2. Royal College of Obstetricians and Gynaecologists. The Management of Ovarian Hyperstimulation Syndrome. RCOG. 2016 Feb. Open 3. Pfeifer S, Butts S, Dumesic D et al. Prevention and treatment of moderate and severe ovarian hyperstimulation syndrome: a guideline. Fertil Steril. 2016 Dec;106 7 1634 1647. Open 4. Corbett S, Shmorgun D, Claman P et al. The prevention of ovarian hyperstimulation syndrome. J Obstet Gynaecol Can. 2014 Nov;36 11 1024 1033. Open https://web.pathway.md/diseases/recN605IEcZt9Ht8Q 6/6