OHSS Risk Factors

Ovarian hyperstimulation syndrome (OHSS) occurs in up to 10 percent of women undergoing in vitro fertilization or intrauterine implantation treatment to induce pregnancy. During ovulation induction, fertility drugs increase the number of follicles in the ovaries, which sometimes causes a mild condition in which the ovaries become over-stimulated, swollen and painful. Some women may develop a severe form that can lead to fluid accumulation in the lungs, blood clots and kidney failure. Roughly 1 percent of patients require a hospital stay as a result of their treatment, although most IVF or intrauterine implantation patients see symptoms disappear within a few weeks without any treatment. Understanding the risks of fertility clinics is important for women who can't conceive on their own.

Symptoms

• Patients with mild cases of OHSS may notice abdominal bloating, mild stomach pain, nausea, diarrhea and weight gain. These symptoms appear because the ovaries have been stimulated more than usual during fertility treatment, which causes them to temporarily swell up and become more fragile. Levels of estrogen and progesterone increase, which may upset the digestive system's balance and contribute to dehydration.

  Patients with more severe cases of OHSS can gain up to 10 lbs. in a few days. Women experience intense abdominal pain, extreme nausea, vomiting, dizziness, shortness of breath and decreased urination that is typically tea-colored. In some cases, the calves and chest are seized with pain as abnormal blood clots develop. Serious cases of OHSS involve extremely large ovaries with fluid that fills the patient's lungs and chest cavity, causing these unpleasant and possibly deadly symptoms.

Complications

• Mild OHSS cases generally clear up automatically once menstruation starts or over a few weeks' time if pregnancy occurs, but serious complications can occur if patients don't seek medical treatment for severe OHSS. Women should call their doctor if they experience fast weight gain, decreased urination, nausea so bad they can't keep liquids down and severe abdominal pain above and below the belly button.
  Though severe cases are rare, reports indicate women whose swollen ovaries twisted in bizarre ways, which resulted in loss of fertility and ovary removal. Other reports tell of fluid retention in the stomach and lungs that impaired breathing. Kidneys and livers are unfortunate casualties in many serious cases because urination is often halted. Fatal reports of blood clots and strokes occur in 1 out of every 450,000 to 500,000 cases.

Causes

• As previously mentioned, ovarian hyperstimulation syndrome is an occasional side effect of in vitro fertilization or intrauterine implantation, occurring in roughly 10 percent of all cases. However, of those cases, 25 percent were injected with the human chorionic gonadotropin hormone designed to trigger ovulation. The adverse reaction to the hormone shows symptoms within 10 days of receiving the injection. In exceedingly rare instances, OHSS randomly occurs in pregnant women who did not undergo ovulation induction to conceive.

Risk Factors

• Any woman receiving ovulation induction can develop OHSS. Certain risk factors almost guarantee a woman's chances of getting the condition, though. For instance, women who are under 30 and underweight are more likely to have it. Additionally, women who have had previous cases of OHSS or polycystic ovarian syndrome -- a reproductive disorder that causes irregular menstrual periods--are at greater risk. Lastly, women may develop OHSS if they have a large number of follicles or if they were administered high levels of estrogen before an HCG shot. Young women with polycystic ovarian syndrome are most at risk, according to the Mayo Clinic, but even women with no risk factors can have this condition and it's still unknown exactly what causes such adverse reactions in some patients.

Treatment

• A woman with OHSS should tell her doctor or reproductive endocrinologist about her symptoms. The doctor will then stop infertility drug treatment, ask that she cease sexual activities, remove excess fluids in the stomach and monitor her urination and weight gain. Over-the-counter pain and nausea medications alleviate some of the mild symptoms. Moderate symptoms require urine output measurements, blood tests to monitor dehydration, prescription painkillers and ultrasound exams. Severe symptoms require hospitalization, intravenous fluids and surgical repair of organ complications or a ruptured ovarian cyst. Strenuous activity should be avoided during treatment, although light tasks should be completed to avoid blood clotting.

Prevention

• Careful monitoring of ovaries, follicle development and blood estrogen levels are the best ways to prevent ovarian hyperstimulation syndrome. At-risk patients should be given the lowest possible dose of gonadotropins to trigger ovulation. If follicles are developing at a rapid pace or estrogen levels are too high, the injections should be stopped a few days before the HCG injection. An expensive luteinizing hormone or gonadotropin-releasing hormone agonist can be substituted for the usual HCG injection as another preventative method. A number of women decide to freeze mature, fertilized follicles and embryos, as the ovaries recover for two cycles. Later, the embryos are thawed and implanted back into the uterus in a procedure that negates the chance of OHSS. The downside of these preventative methods is that they cost more and decrease the chance of pregnancy. Better future treatments can be developed if more clinical studies are completed.