Ovarian hyperstimulation syndrome (OHSS) is caused by the use of ovulatory drugs during pregnancy assistance and is related to the patient’s sensitivity and endocrine status, the type and amount of drugs, and the presence or absence of pregnancy. In severe cases, lack of appropriate treatment can lead to life-threatening conditions, and is a serious medically induced disease.
1. Incidence.
The overall incidence of OHSS is about 20% in patients receiving ovulation promotion therapy, and about 1% in moderate and severe cases.
2%. The incidence of OHSS in pregnancy cycles is 4 times higher than in non-pregnant cycles. Patients who are sensitive to gonadotropin response, high estrogen levels and higher number of eggs retrieved are at increased risk of OHSS, and younger patients or PCOS patients with ovulation are prone to OHSS.
2. Classification.
OHSS grading
OHSS grading
Mild
I
Abdominal distension and discomfort
II
Grade I symptoms + nausea, vomiting and/or diarrhea
Different degrees of ovarian enlargement, 5 to 12 cm in diameter
Moderate
III
Mild OHSS with increased symptoms +
Ultrasound evidence of ascites
Severe
IV
Moderate OHSS features +
Clinical evidence of ascites or pleural fluid and dyspnea
V
Hematocrit >45% (>30% elevation from baseline)
WBC>15000/mL
Oliguria, blood creatinine 1.0 to 1.5 mg/dl
Creatinine clearance ≥50mL/min
abnormal liver function, generalized edema
Critically ill
VI
Tension ascites +/0 pleural fluid
Hematocrit>55%
WBC>25000, creatinine>1.6mg/dl
Creatinine clearance >50mL/min
renal failure
Thromboembolism
Acute respiratory distress syndrome (ARDS)