Ovarian Hyperstimulation Syndrome

Lee A Fox, MD
Mary Frates, MD

December 10, 1996

Presentation

Imaging Findings

Transabdominal sonograms demonstrate bilateral ovarian enlargement. The right ovary (arrow) measures 10.9 x 8.5 x 7.4 cm and contains multiple complex and simple cysts. The largest cyst measures 4.4 x 3.6 x 3.3 cm. The left ovary (arrow) measures 9.9 x 9.2 x 8.3 cm and also contains multiple cysts, the largest of which (arrow) measures 6.7 x 6.2 x 7.0 cm. The endometrium (black arrow) is thick and echogenic. No gestational sac is visible within the uterine cavity.

A large amount of free fluid is visible in both the cul-de-sac (black arrows) and above the uterus (white arrow). Free fluid is also identified in both upper quadrants (arrows). Bilateral pleural effusions (white arrows) are demonstrated, right larger than left. The kidneys are normal.

Diagnosis

Discussion

1. Ovarian follicle stimulants are administered. At this time the circulating estrogen levels are high; the ovaries respond to these elevated hormonal levels by enlarging.
2. Multiple ovarian follicles are simultaneously stimulated and can be identified in the uterus by ultrasound examination. Ovulation then occurs either spontaneously or by iatrogenic supplementation of human chorionic gonadotropin (hcG). It is during this second phase of the cycle, following ovulation, that OHSS may develop.

Three grades of OHSS can be distinguished by clinical and sonographic criteria. In mild OHSS, the patient may complain of mild abdominal discomfort and the ovaries are usually less than 5 cm in diameter on sonographic examination. With moderate OHSS, the ovaries measure between 5 and 10 cm, and in the severe form, the ovaries are greater than 10 cm in diameter. Severe OHSS is characterized by the presence of free intraperitoneal fluid. Pleural effusions, hypotension, and oliguria have also been described. Clinically, the patient may have fluid and electrolyte disturbances and is at increased risk for torsion of the enlarged ovaries.

Sonographic and laboratory findings can help predict which patients are more likely to develop OHSS. Serum estradiol levels are the most accurate indicator. A value of 4000 pg/mL or greater at the time of hCG administration correlates with a higher likelihood of developing the syndrome. Sonographically, if more than eight follicles develop in an ovary, the patient is at increased risk for OHSS.

The treatment of OHSS is often careful observation. Some patients require hospitalization and supportive therapy. If no pregnancy occurs, the syndrome will typically resolve within one week. In the setting of a maintained pregnancy, slow resolution of symptoms usually occurs over 1 to 2 months.

This patient 's ovarian induction therapy was successful. A single intrauterine gestation has been followed into the second trimester and is progressing normally. The ovaries gradually returned to normal and the free fluid resolved.

References

• Return to the Teaching Case Database search page
• Return to Professional Education
  
• About BrighamRAD

Dear Visitors: Nothing on this World Wide Web site should be considered medical advice. Only your own doctor can help you make decisions about your medical care. It is not the policy of the Brigham and Women's Hospital Department of Radiology to provide consultation on the World Wide Web or via e-mail. If you have a specific medical question or are seeking medical care, please call the Brigham and Women's Hospital toll-free physician referral line at 1-800-294-9999.

Is this a mirrored page?
The official homepage of the BrighamRAD Teaching Case Database is http://brighamrad.harvard.edu/education/online/tcd/tcd.html