Ovarian Hyperstimulation

OHSS symptoms usually appear a few days after ovulation is triggered with an injection of hCG.

Ovarian Hyperstimulation Syndrome (OHSS) is an exaggerated response to the use of ovulation induction drugs, especially during the use of injectable gonadotropin agents. However, it can, on rare occasions, be associated with the use of clomiphene citrate or gonadotropin-releasing hormone. It can occur a week after the HCG injection ( Early type) or after the pregnancy is confirmed ( Late type). It can last for 1-3 weeks and is longer if there is more than one sac, Women with OHSS have an increase in fluid

Symptoms range from bloating to nausea to swelling of the abdomen. On rare occasions, women have to be hospitalized when symptoms are more severe. OHSS is most common in women who are having IVF when serum estradiol levels are high. It is most likely to develop when a large number of ovarian follicles (immature eggs) have developed. leaking from the blood capillaries. OHSS is characterized by enlarged ovaries and fluid accumulation in the abdomen after stimulation. A mild form occurs in 10% to 20% of cycles and results in some discomfort but usually resolves quickly without complications. The chance of OHSS is increased in women with polycystic ovary syndrome and in women who become pregnant during the cycle in which gonadotropins are given. OHSS can be classified as mild, moderate or severe, based on symptoms and laboratory findings. One out of three women have some symptoms of mild OHSS when they have controlled ovarian stimulation during IVF cycles. Women with severe OHSS usually have vomiting and cannot keep down liquids. They have an increase in discomfort from distention (swelling) of the abdomen (belly). In the worst cases, they can develop shortness of breath. Ovary size is also used as a marker of OHSS. If you have symptoms, a transvaginal ultrasound can be done to measure ovary size.

TREATMENT OF OHSS

Prevention. Several strategies exist to prevent or minimize symptoms, including withholding further gonadotropin stimulation, delaying hCG administration until hormone levels plateau or decline, or even withholding hCG to prevent ovulation. In IVF cycles in which OHSS is felt likely to develop, an oral medication, cabergoline, may be given to lessen the severity of these symptoms. Another way to shorten the time that a patient may have OHSS symptoms is to consider delaying the embryo transfer in IVF couples by freezing (cryopreserving) the embryos and transferring at a later date when the OHSS symptoms are completely resolved.

Mild to moderate OHSS is treatable with decreased activity, monitoring the amount of fluids you are taking in and how much urine you are putting out, and medicines for nausea. Severe OHSS is treated in the hospital. At the hospital, the doctor will give you an IV (intravenous hydration), medicines for nausea, watch you closely and may remove fluid from your abdomen. Other supportive therapy may be given as needed.

SEVERE OHSS

Complications from OHSS can be severe. You may become dehydrated (severe loss of fluid from the bloodstream) and pressure may increase from too much fluid in the abdomen. These factors increase the risk of blood clots forming within the blood vessels. Blood clots can travel to the lungs or to other important organs. This can be potentially life-threatening. These complications can almost always be avoided by recognizing the signs, symptoms and laboratory evidence that OHSS is getting worse. Then appropriate treatment, inside or outside of a hospital, can be given. In some cases, you might have to take medicine to prevent blood clots.

DURATION OF OHSS

OHSS symptoms usually appear a few days after ovulation is triggered with an injection of hCG. These symptoms will usually go away within a week unless pregnancy occurs. Pregnant women will continue to have OHSS symptoms for 2 to 3 weeks or more after a positive pregnancy test. These symptoms gradually go away, and the remainder of the pregnancy is unaffected.

IMPORTANT POINTS

Mild to moderate OHSS is relatively common after ovarian stimulation for IVF or ovulation induction. Women need to be seen by their treating physician or another physician familiar with assisted reproductive) as soon as they have symptoms. A standard gynecologic pelvic examination is NOT generally recommended because the ovaries are enlarged and the cysts that are present may burst open under pressure. Mild to moderate OHSS (with tolerable nausea, vomiting, and abdominal swelling) can often be treated at home with decreased activity, drinking fluids, medication for nausea, careful monitoring, and frequent doctor visits. Severe OHSS (with continued vomiting, severe swelling of the abdomen, shortness of breath or noticeable laboratory abnormalities) requires hospitalization for treatment and intensive monitoring. Ectopic (Tubal) Pregnancies. While ectopic pregnancies occur in 1% to 2% of naturally occurring pregnancies, in gonadotropin cycles the rate is slightly increased. Ectopic pregnancies can be life-threatening and require treatment with medication or surgery. Occasionally a tubal pregnancy can occur at the same time as an intrauterine pregnancy (heterotopic pregnancy) and requires surgery to remove the ectopic pregnancy while not harming the pregnancy inside the uterus. Adnexal Torsion (Ovarian Twisting). In less than 2% of gonadotropin cycles, the stimulated ovary can twist on itself since the ovary is heavier from more follicles. This twisting can cut off the blood supply. Therefore, surgery is required to untwist the ovary, or in severe cases, to remove the ovary. Gonadotropins and Cancer. Current studies have shown no increase in any cancers with the use of fertility medications. Local or Generalized Reactions. In some women, the injection may cause local skin irritation. It is extremely rare to have an actual allergy to the medication. Some women may experience breast tenderness, headaches, or mood swings from the gonadotropins.