II. Pathophysiology
- Hyperstimulation occurs with gonadotropin stimulation for Ovulation induction or Invitro Fertilization (IVF) Cycles
- Hyperstimulation increases ovarian capillary permeability and neoangiogenesis
III. Risk Factors
- Younger patients
- Lower body weight
- Polycystic ovarian syndrome
- High dose exogenous gonadotropins
- Increased Serum Estradiol (E2) levels (rapidly increasing or high absolute level)
- More than 24 oocytes retrieved
- Past history of Ovarian Hyperstimulation Syndrome (OHSS)
IV. Symptoms
V. Grading: Golan Classification for Ovarian Hyperstimulation Syndrome (OHSS)
- Mild Ovarian Hyperstimulation (20-33% of OHSS cases)
- Ovarian Size <6 cm
- Grade 1: Abdominal Distention
- Grade 2: Abdominal Distention, Nausea, Vomiting and Diarrhea
- Moderate Ovarian Hyperstimulation (3-6% of OHSS cases)
- Ovarian Size 6-12 cm
- Grade 3: Ascites on Ultrasound and weight gain, in addition to Grade 2 symptoms
- Severe Ovarian Hyperstimulation (0.1 to 2% of OHSS cases)
- Ovarian Size >12 cm
- Grade 4: Ascites and Hydrothorax, in addition to Grade 2 Symptoms
- Grade 5: Ascites and Hydrothorax with Hypovolemia, hemoconcentration, Coagulation Disorder, Oliguria, shock
VI. Labs
-
Complete Blood Count
- Hemoconcentration (increased Hematocrit >45%)
- Leukocytosis (White Blood Cell Count >15,000)
- Comprehensive Metabolic Panel
- Hyponatremia (Serum Sodium <135)
- Hyperkalemia (Serum Potassium >5.0)
- Iincreased ALT and AST liver enzymes
- Increased Serum Creatinine (>1.2 mg/dl)
VII. Imaging
- Pelvic Ultrasound
- Measure ovarian size (<6 cm, 6-12 cm or >6 cm)
- Evaluate for Ascites (significant free abdominal fluid)
- Ascites and hemoperitoneum (e.g. ruptured Ovarian Cyst) may be indistinguishable on Ultrasound
- Consider CT Abdomen and Pelvis to characterize large intraabdominal fluid collection
-
Lung Ultrasound or Chest XRay
- Indicated in Dyspnea, for evaluation of Pleural Effusions or hydrothorax
-
CT Abdomen and Pelvis
- Consider in severe cases (Hounsfield Units may distinguish intraabdominal blood from Ascites)
VIII. Management
- Consult patient's reproductive specialist
- Hospital monitoring indications
- Outpatient management is often indicated in Mild to moderate Ovarian Hyperstimulation Syndrome (OHSS)
- Requires close interval follow-up
- Serial labs (interval and lab type per reproductive specialist guidance)
- Monitor intake and output, daily weight and abdominal circumference
IX. Complications
- Acute Renal Failure
- Acute Respiratory Distress Syndrome (ARDS)
- Ruptured Ovarian Cyst with Hemorrhage
- Thromboembolism (OHSS is a Hypercoagulable state)
X. References
- Gallo, Suyama and Snook (2020) Crit Dec Emerg Med 34(10): 3-7
- Zivi (2010) Semin Reprod Med 28(6): 441-7 [PubMed]