Diagnostic Ultrasound - Abdomen and Pelvis

Ovarian Hyperstimulation Syndrome
810
Diagnoses: Female Pelvis
○ Shortness of breath from pleural effusion
○ Hypotension
○ Electrolyte imbalance
○ Hepatic dysfunction
• Relative hemoconcentration due to fluid leaking into
peritoneal/pleural spaces
○ Oliguria
○ Hypercoagulability
• Rarely associated with venous occlusive disease or
thromboembolic events
○ Usually only with severe OHSS
Demographics
• Epidemiology
○ Typically seen in women undergoing ovulation induction
– More commonly with gonadotropin stimulation for in
vitro fertilization (IVF)
– Less commonly seen with clomiphene induction
□ Severe form rarely seen
○ Mild OHSS: 20-33%of IVF cases
○ Moderate OHSS: 3-6% of IVF cases
○ Severe OHSS: 0.1-2.0% of IVF cases
• Risk factors
○ Polycystic ovarian syndrome major risk factor
– May be related to increased number of
follicles/oocytes produced when stimulated
– Oligomenorrhea itself also risk factor
○ Greater number of follicles stimulated during IVF
– High or rapidly increasing serum estradiol
○ Younger age
○ Previous OHSS history
○ Low body mass index
Natural History & Prognosis
• Occurs after ovulation
○ Early type occurs < 5 days after oocyte retrieval
– Induced by exogenous hCG administration
○ Late type occurs ≥ 5 days (range 5-15 days) after oocyte
retrieval
– Induced by endogenous hCG from implanted
pregnancy
– Late type always associated with pregnancy
• Should be self-limiting as long as supportive care started
early in process
• Usually regresses over 10-14 days unless pregnancy
implantation occurs
○ Subsequently can have increase in endogenous hCG
○ May prolong OHSS or initiate late form of OHSS
• More severe in patients who become pregnant
• Severe OHSS potentially life-threatening
○ Mortality estimated at 1:45,000 cases of OHSS
Treatment
• No known therapy to immediately reverse OHSS
• Avoid pelvic trauma to ovaries
○ No intercourse, pelvic exams, strenuous exercise
• Conservative therapy with observation warranted
○ May be monitored as outpatient
– Frequent vital sign and electrolyte checks
○ Maintain intravascular volume and urine output
– 24 urine volume measurements
– Daily weights
○ Consider US-guided paracentesis or thoracentesis for
symptoms
– Serial abdominal girth measurements
○ Prophylactic anticoagulation
– Useful due to relative hemoconcentration
• Some advocate proactive management to shorten course
of symptoms
○ Most often considered if moderate to severe OHSS
○ Actively administer fluids &/or albumin
– Diuretics considered when adequate intravascular
volume achieved
○ Benefits of US-guided paracentesis
– ↓ hospitalization
– ↓ hemoconcentration
– ↑ urine output
– Ameliorates electrolyte abnormalities
• May require hospitalization for management of severe
symptoms
○ Intractable pain
○ Intractable nausea/vomiting
○ Respiratory difficulties
○ Suspected infection/hemorrhage
• Surgical intervention only rarely required
○ Ovarian torsion
○ Cyst rupture with hemoperitoneum
• Partial oophorectomy for severe cases reported
DIAGNOSTIC CHECKLIST
Image Interpretation Pearls
• Avoid aggressive transvaginal imaging as ovaries can be
friable
• Correlate imaging appearance of ovaries with clinical
history for diagnosis
SELECTED REFERENCES
1. Mathur RS et al: British fertility society policy and practice committee:
prevention of ovarian hyperstimulation syndrome. Hum Fertil (Camb).
17(4):257-68, 2014
2. Nastri CO et al: Ovarian hyperstimulation syndrome: physiopathology,
staging, prediction and prevention. Ultrasound Obstet Gynecol. ePub, 2014
3. Thornton KG et al: Ovarian Hyperstimulation Syndrome and Arterial Stroke.
Stroke. ePub, 2014
4. Baron KT et al: Emergent complications of assisted reproduction: expecting
the unexpected. Radiographics. 33(1):229-44, 2013
5. Tan BK et al: Management of ovarian hyperstimulation syndrome guidelines.
Produced on behalf of the BFS Policy and Practice Committee. Hum Fertil
(Camb). 16(3):160-1, 2013
6. Kumar P et al: Ovarian hyperstimulation syndrome. J Hum Reprod Sci.
4(2):70-5, 2011
7. Nastri CO et al: Ovarian hyperstimulation syndrome: pathophysiology and
prevention. J Assist Reprod Genet. 27(2-3):121-8, 2010
8. Zivi E et al: Ovarian hyperstimulation syndrome: definition, incidence, and
classification. Semin Reprod Med. 28(6):441-7, 2010
9. Bartkova A et al: Acute ischaemic stroke in pregnancy: a severe complication
of ovarian hyperstimulation syndrome. Neurol Sci. 29(6):463-6, 2008
10. Kim IY et al: Ovarian hyperstimulation syndrome. US and CT appearances.
Clin Imaging. 21(4):284-6, 1997