Ovarian Hyperstimulation Syndrome

Authors: Thomas Mac Mahon / Editors: Frances Balmer / Codes: / Published: 04/04/2025

Ovarian hyperstimulation syndrome (OHSS) is an iatrogenic complication of fertility treatment. Whilst rare, it is important for emergency physicians to consider the possibility of OHSS in patients undergoing fertility treatment, as the symptoms can be subtle and easily missed, with potentially serious associated morbidity and mortality.

Learning objectives

After completing this session, you will be able to:

• Appreciate the low incidence but potential high morbidity of severe or critical OHSS
• Understand the pathophysiology, symptoms and signs of OHSS
• Classify the severity of OHSS using clinical and laboratory criteria
• Recognise the emergency treatment priorities for patients with OHSS
• Identify the increased potential for venous thromboembolism in this patient cohort, especially presenting late and with unusual symptoms
• Avoid common pitfalls in the diagnosis and management of OHSS

References

1. Mathur R, Drakeley A, Raine-Fenning N, et al. The management of ovarian hyperstimulation syndrome. Green-top guideline no. 5. London, UK: Royal College of Obstetricians and Gynaecologists, 2016.
2. Human Fertilisation and Embryology Authority. State of the fertility sector 2023/24. London, UK. 2024. [accessed 09 December 2024].
3. Sokteang S, Pirtea P, Toner JP, et al. Ovarian hyperstimulation syndrome should be dead, we are just waiting on the obituary. Fertil Steril 2024;122(2):230-32. doi: 10.1016/j.fertnstert.2024.02.040
4. Alyasin A, Mehdinejadiani S, Ghasemi M. GnRH agonist trigger versus hCG trigger in GnRH antagonist in IVF/ICSI cycles: A review article. Int J Reprod Biomed 2016;14(9):557-66.
5. Timmons D, Montrief T, Koyfman A, et al. Ovarian hyperstimulation syndrome: A review for emergency clinicians. The American journal of emergency medicine 2019;37(8):1577-84. doi: 10.1016/j.ajem.2019.05.018
6. Mor YS, Schenker JG. Ovarian hyperstimulation syndrome and thrombotic events. Am J Reprod Immunol 2014;72(6):541-8. doi: 10.1111/aji.12310
7. Evbuomwan I. The role of osmoregulation in the pathophysiology and management of severe ovarian hyperstimulation syndrome. Hum Fertil (Camb) 2013;16(3):162-7. doi: 10.3109/14647273.2013.831996
8. Mathur RS, Akande AV, Keay SD, et al. Distinction between early and late ovarian hyperstimulation syndrome. Fertil Steril 2000;73(5):901-7. doi: 10.1016/s0015-0282(00)00492-1