Ovarian hyperstimulation syndrome

Background

Female pelvic anatomy.

• Fertility treatments causing development of multiple follicles at once
  • Exaggerated ovarian response to ovulation induction (esp in IVF when HCG is used to stimulate)
• Fluid shifts out of vasculature (third spacing)
• Typically 5-10d after 1st dose
• Ranges in severity from mild to severe multiorgan dysfunction, relating in part to massive intravascular fluid shifts

Clinical Features

• Ovarian enlargement
• Movement of fluid out of vasculature
  • Ascites
  • Pleural effusions
  • Pericardial effusion
  • Hypotension
• Electrolyte imbalances
• DIC
• Thromboembolism
  • Both venous and arterial
• Hypervolemic hyponatremia

Differential Diagnosis

• Ectopic pregnancy
• Molar pregnancy
• Sepsis
• Pulmonary embolism in pregnancy

Acute Pelvic Pain

Differential diagnosis of acute pelvic pain

Gynecologic/Obstetric

• Normal variants may be noted on exam but generally do not cause pain or other symptoms
  • Nabothian cysts: Epithelial cells within mucous glans that appear as yellow inclusions on the cervix
  • Cervical Ectropion: Edothelial cells on the exterior of the cervix
  • Parous cervix: The is no longer round but may have multiple shapes after birth
• Pregnancy-related
  • Ectopic pregnancy
  • Spontaneous abortion, threatened or incomplete
  • Septic abortion
• Pelvic organ prolapse
• Acute Infections
  • Herpes
  • Cervicitis
  • Endometritis
  • Bartholin gland abscess
  • Pelvic inflammatory disease (PID)
  • Tubo-ovarian abscess
• Vulvovaginitis
  • Bacterial Vaginosis
  • Candida Vaginitis
  • Trichomonas
  • Contact Vulvovaginitis
  • Atrophic vaginitis
• Adnexal Disorders
  • Hemorrhage/rupture of ovarian cyst
  • Ovarian torsion
  • Twisted paraovarian cyst
• Other
  • Myoma (degenerating)
  • Genitourinary trauma
  • Ovarian hyperstimulation syndrome
  • Sexual assault
• Recurrent
  • Mittelschmerz
  • Primary/Secondary Dysmenorrhea
  • Pelvic Congestion Syndrome
  • Endometriosis

Genitourinary

• Cystitis
• Pyelonephritis
• Urethritis (e.g. N. gonorrhoeae/Chlamydia)
• Urolithiasis

Gastrointestinal

• Gastroenteritis
• Appendicitis
• Bowel obstruction
• Perirectal abscess
• Diverticulitis
• Inflammatory bowel disease
• Irritable bowel syndrome
• Mesenteric adenitis

Musculoskeletal

• Abdominal wall hematoma
• Psoas hematoma, psoas abscess
• Hernia

Vascular

• Pelvic thrombophlebitis
• Abdominal aortic aneurysm
• Ischemic bowel (Mesenteric Ischemia)

Evaluation

Vaginal ultrasonography in mild ovarian hyperstimulation syndrome (coronal).

Pelvic ultrasound (sagittal) in woman with OHSS showing ascites and enlarged ovary (diameter = 6.5mm)

Workup

• Urine or serum pregnancy
  • Beta-HCG may be positive if beta-HCG injection given as part of fertility treatment, consider obtaining beta quantitative instead of qualitative
• CBC
• Chem 10
• PT/PTT
• Pelvic ultrasound
• Consider:
  • CXR (rule out pleural effusion)
  • Cardiac ultrasound (rule out pericardial effusion)
  • Progesterone level
  • Estradiol level
  • Fibrinogen (rule out DIC)

Evaluation.

Classification	Clinical features	Lab findings
Mild	Abdominal distention/discomfort Mild nausea/vomiting Diarrhea Enlarged ovaries	Normal
Moderate	Above plus: Ultrasonographic evidence of ascites	Elevated hematocrit (>41%) Elevated WBC (>15,000/mL) Hypoproteinemia
Severe	Above plus: Clinical evidence of ascites (can be tense ascites) Severe abdominal pain Intractable nausea and vomiting Rapid weight gain (>1 kg in 24 hours) Pleural effusion Severe dyspnea Oliguria/anuria Low blood/central venous pressure Syncope Venous thrombosis	Hemoconcentration (hematocrit >55%) WBC >25,000/mL Serum creatinine >1.6mg/dL Creatinine clearance <50 mL/min Hyponatremia (Na+ <135 mEq/L) Hyperkalemia (K+ >5 mEq/L) Elevated liver enzymes
Critical	Above plus: Anuria/acute renal failure Arrhythmia Pericardial effusion Massive hydrothorax Thromboembolism Arterial thrombosis ARDS Sepsis	Worsening findings

Management

Pregnant patients must be followed very closely, as they are likely to worsen

• Urgent GYN consultation for all

Mild

• Pain control
  • Acetaminophen, Norco, or morphine
• Encourage oral fluids (1-2 liters/day)
• Ambulate, but avoid other physical activity. Avoid sexual intercourse

Moderate

• IV fluids (e.g normal saline)
• Therapeutic paracentesis if ascites (aspirate 0.5-4 L)
• Thromboembolic prophylaxis (e.g. LMWH)
  • All hospitalized patients
  • Outpatients with 2-3 risk factors:
    • Age >35 years
    • Obesity
    • Immobility
    • Personal or family history of thrombosis
    • Thrombophilias
    • Pregnancy

Severe

• As above + consider need to drain pleural or pericardial effusion

Critical

• As above + resuscitative care

Disposition

• Mild: outpatient
  • Avoid heavy physical activity
  • Return for
    • Worsening abdominal pain
    • Weight gain (>1 kg/day)
    • Increasing abdominal girth
• Moderate: outpatient if close follow-up (discuss with GYN)
• Severe: admit
• Critical: ICU

Complications

• Ovarian torsion
• Venous thromboembolism
• Hydrothorax
• Pericardial effusion
• Arterial thrombosis
• Pulmonary embolism
• Sepsis
• Acute renal failure
• Acute respiratory distress syndrome (ARDS)
• Disseminated intravascular coagulation (DIC)

See Also

• Ectopic Pregnancy
• Shock