AART - Risks

There is no known increased risk of abnormality in babies born as a result of IVF procedures. There are some risks associated with IVF therapies.

These include:

  • Mild discomfort and bruising of the arm as a result of repeated blood testing and injections.
  • In 1-3% of cases, medications may over-stimulate the ovaries. This so-called hyperstimulation syndrome causes lower abdominal pelvic pain or cramping and can cause difficulties in breathing. This discomfort is due to the formation of excessively large ovarian follicles or cysts. Treatment may have to be cancelled. In rare circumstances, hospitalization and other treatments may be necessary to relieve the condition.
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    Ovarian Hyperstimulation Syndrome

    The symptoms are abdominal swelling or bloating because of enlarged ovaries, nausea and, as the condition gets worse, vomiting.

    • Mild OHSS – mild abdominal swelling or bloating, abdominal discomfort and nausea
    • Moderate OHSS – symptoms of mild OHSS but the swelling and bloating is worse because fluid is building up in the abdomen, There is abdominal pain and vomiting.
    • Severe OHSS – symptoms of moderate OHSS plus extreme thirst and dehydration because so much fluid is building up in the abdomen, passing very small amounts of urine which is very dark in color (concentrated), difficulty breathing because of build-up of fluid in the chest and a red, hot, swollen and tender leg due to a clot in the leg or lungs (thrombosis). If you develop any of the symptoms, seek medical help immediately.


    Fertility drugs stimulate the ovaries to produce many egg sacs (follicles). Sometimes there is an excessive response to fertility drugs and this causes OHSS. Overstimulated ovaries enlarge and release chemicals into the bloodstream that make blood vessels leak fluid into the body. Fluid leaks into your abdomen and, in severe cases, into the space around the heart and lungs. OHSS can affect the kidneys, liver, and lungs. A serious, but rare, complication is a blood clot (thrombosis). A very small number of deaths have been reported world wide.

    Mild symptoms are common in women having IVF treatment. As many as one in three (33%) women develop mild OHSS. About one in 20 (5%) women develop moderate or severe OHSS.

    The risk of OHSS in increased in women who:

    • Have polycystic ovaries
    • are under 30 years
    • have had OHSS previously
    • get pregnant, particularly if this is a multiple pregnancy (twins or more).
    • have very high blood levels of estradiol in response to FSH injections.
    • have very high numbers of follicles develop in response to FSH injections

  • Vaginal ultrasound-guided pickup is usually associated with some discomfort. If it is significant, additional medication can be given during or after the procedure. In less than 1% of cases, bleeding or pelvic infection may also occur after the egg retrieval process.
  • Where more than one embryo is transferred, there is a much higher risk of Multiple Pregnancy. Multiples occur in approximately 30% of treatments, with the majority being twins, however higher order multiples, such as triplets, can occur in 2% of patients undergoing IVF. As a result, AART’s policies limit the number of embryos that it will transfer into a woman’s uterus and we encourage single embryo transfer when appropriate.
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    Impact of Multiple Pregnancy

    With spontaneous conceptions, a little more than 1% of pregnancies will be multiples (twins, triplets, or more). This rate is significantly increased with in-vitro fertilization (IVF), so that in Canada the risk of a twin pregnancy is approximately 30% and that of triplets or more is approximately 2% with IVF. Risks increase with the number of embryos transferred to the uterus in IVF. For a couple dealing with the anguish of infertility, a multiple pregnancy may appear to be a good outcome. However, there are a number of serious complications associated with multiple pregnancy that make it considerably less desirable than a single fetus pregnancy.Many of the complications of pregnancy that a mother may experience (high blood pressure, bleeding, diabetes) are increased. The number of physician visits, ultrasound examinations, and days in hospital are far more with a twin or triplet pregnancy. The frequency of Cesarean Section is in the range of 50% with a twin pregnancy, and is advised in virtually all triplet or higher pregnancies.

    By far, the most serious issue is that of achieving the goal of a live-born, healthy child. The biggest concern with multiple pregnancy is the risk of pre-term birth. Twins are born on average five weeks prior to term, triplets eight weeks prior to term, and quadruplets or higher more than ten weeks prior to term. A great majority of pre-term twin and virtually all triplets and quadruplets spend periods of time (sometimes prolonged) in newborn intensive care. There is the need for ventilator or respirator care, and complications such as brain hemorrhage, leading to increased risks of developmental delay and cerebral palsy. Chronic long-term respiratory difficulties, visual impairment, and bowel disorders are greatly increased with pre-term birth. The risk of death and cerebral palsy is up to five times greater for a twin newborn and more than ten times greater for a triplet newborn than for a single birth.

    These realities are why care providers encourage careful consideration of the number of embryos transferred, so as to reduce the risk of multiple pregnancy while achieving ideal live birth success rates.

  • In about 3-4% of treatments, an embryo implants in the fallopian tube or other location outside of the uterine cavity resulting in a tubal pregnancy. This necessitates either medical treatment with a drug called Methotrexate or surgical removal of the embryo as it can neither remain in the tube nor be transferred to the uterus.
  • Stress is inevitably associated with IVF procedures. Couples are encouraged to contact AART for counseling or appropriate referral for coping with this stress or with IVF failure.
  • 8% of IVF cycles are cancelled for a variety of reasons.
  • Very rarely, no eggs are obtained during egg retrieval.

Assessment After a Completed Cycle

The AART team will review your therapies whether or not pregnancy occurs after treatment. A physician will meet with you after the review has taken place to discuss the cycle and to recommend adjustments should another cycle be undertaken.