Ovarian hyperstimulation syndrome

Ovarian hyperstimulation syndrome may occur after using injectable hormone medications during in vitro fertilization (IVF), a treatment for infertility. Injectable fertility medications stimulate the development of eggs in the ovaries, but it can be difficult to tell exactly how much medication you might need.

Too much of the hormone in your system can lead to ovarian hyperstimulation syndrome (OHSS), where your ovaries become swollen and painful. A small number of women may develop severe OHSS, which can cause rapid weight gain, abdominal pain, vomiting and shortness of breath.

Less often, OHSS happens during fertility treatments using medications you take by mouth, such as clomiphene. Occasionally OHSS occurs spontaneously, not related to fertility treatments.

Symptoms Causes Risk factors Complications Prevention

Symptoms of ovarian hyperstimulation syndrome often begin within 10 days after using injectable medications to stimulate ovulation. Symptoms can range from mild to severe and may worsen or improve over time.

Mild to moderate OHSS

With mild to moderate ovarian hyperstimulation syndrome, symptoms can include:

  • Mild to moderate abdominal pain that may come and go
  • Abdominal bloating or increased waist size
  • Nausea
  • Vomiting
  • Diarrhea
  • Tenderness in the area of your ovaries

Some women who use injectable fertility drugs get a mild form of OHSS, which goes away after about a week. If pregnancy occurs, however, symptoms of OHSS may worsen and last several days to weeks.

Severe OHSS

With severe ovarian hyperstimulation syndrome, you might have:

  • Rapid weight gain — such as 5 pounds (2.3 kilograms) in one day or 10 pounds (4.5 kilograms) in three days or more
  • Severe abdominal pain
  • Severe, persistent nausea and vomiting
  • Decreased urination
  • Dark urine
  • Shortness of breath
  • Tight or enlarged abdomen
  • Dizziness

When to see a doctor

If you're having fertility treatments and you experience symptoms of ovarian hyperstimulation syndrome, tell your doctor. Even if you have a mild case of OHSS, your doctor will want to observe you for sudden weight gain or worsening symptoms.

Contact your doctor right away if you develop breathing problems or pain in your legs during your fertility treatment. This may indicate an urgent situation that needs prompt medical attention.

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