Ovarian Hyperstimulation Syndrome

Ultrasound images show enlarged ovaries with multiple cysts in a woman who had received assisted reproduction procedure. Ascites is also present but not shown on these images.

Facts: Ovarian Hyperstimulation Syndrome (OHSS)

• Complication related to exogenous administration of human chorionic gonadotropin (HCG) for assisted reproduction
• Believed to be due to increased capillary permeability, resulting in fluid shift from intravascular to extravascular compartments
• Broad clinical spectrum, ranging from mild, moderate to severe, but can be life threatening
• Common in mid- to late-luteal phase
• Early signs: abdominal heaviness, tension and pain (due to bilateral ovarian enlargement with multiple cysts)
• Risk factors: young patient (less than 30 years old), underlying polycystic ovaries, high number of follicles and estradiol levels at the time of HCG injection, protocols that utilize GnRH
• Golan classification describes 5 grades of OHSS based on ovarian size, symptoms (abdominal distention, nausea, vomiting, dyspnea), signs (ascites, pleural effusion, hemoconcentration, hypovolemia, oliguria).

Imaging

• Ultrasound most appropriate imaging to confirm clinical suspicion
• Enlarged ovaries with several cysts
• Ascites, pleural effusion
• Necklace sign (string of ovarian follicles close to the surface of the ovary) may indicate an increased risk of developing this syndrome

Reference:

1. Gianaroli L, Ferraretti AP, Fiorentino A. The ovarian hyperstimulation syndrome. Reproductive Med Rev 1996;5:169-184.

2. Golan A, Ron-El R, Herman A, et al. Ovarian hyperstimulation syndrome: an update review. Obstet Gyncol Surv 1989;44:430-440.