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Chemotherapy
Many chemotherapy (or chemo) drugs will damage some of the
eggs stored in the ovaries. The effect will depend on the type and dose
of chemo. It is hard to predict how many women will stay fertile after
chemo since the woman's age, the types of drugs she gets, and her drug
dose all make a big difference. The drugs most likely to
cause infertility are the alkylating drugs and nitrosoureas such as:
- cyclophosphamide (Cytoxan®)
- ifosfamide (Ifex®)
- melphalan (Alkeran®)
- busulfan
- procarbazine
- chlorambucil (Leukeran®)
- carmustine (BCNU)
- lomustine (CCNU)
- semustine
Chemotherapy drugs that have a low risk of causing infertility
include:
- methotrexate
- 5-fluorouracil (5-FU)
- vincristine (Oncovin®)
- bleomycin
- dactinomycin
Women who were treated for cancer before they were 30 have the
best chance of becoming pregnant after treatment. The good news is that
young women who stop having menstrual periods during treatment often
start having periods again after they are off chemo for a while. Women
are usually advised not to get pregnant within the first 6 months after
chemo because the medicine may have damaged their maturing eggs. If a
damaged egg is fertilized, the embryo could miscarry or develop into a
baby with a genetic problem. But even if a woman's periods start back
after cancer treatment has stopped, her fertility is still uncertain.
Usually some eggs are destroyed by cancer treatment. This
means that even girls who had chemo before puberty (the time when
periods begin and other body changes happen like growth of breasts and
body hair) or young women whose menstrual periods start back after
chemo are at some risk for early (premature) menopause.
When a woman stops having periods long before the average age
of 51, it is considered premature menopause. She becomes infertile
because her ovaries have no more eggs left. Early menopause also means
that the ovaries stop making the female hormones estrogen and
progesterone.
Bone marrow or stem cell transplant
Bone marrow or stem cell transplant usually involves high
doses of chemo and sometimes radiation before the transplant. This
often permanently prevents a woman from producing eggs. Talk with your
doctor or nurse about this risk before starting treatment.
Radiation treatments
Radiation therapy uses high-energy rays to kill cancer cells.
These rays can also damage a woman's ovaries. For a woman having
radiation therapy to the abdomen (belly) or pelvis, the amount of
radiation absorbed by the ovaries will determine if she will become
infertile. High-enough doses can destroy all the eggs in the ovaries
and cause premature menopause. Even if the radiation is not aimed right
at the ovaries, the rays bounce around inside the body and some may
damage the ovaries. When radiation is directed inside the vagina, the
ovaries absorb a high dose of radiation. Radiation to the uterus can
increase the risk of miscarriage, low-birth weight infants, and
premature births. This happens because the treatment can cause scarring
which restricts flexibility and blood flow to the uterus. These
problems can interfere with the growth and expansion of the uterus
during pregnancy.
Sometimes radiation to the brain may affect the pituitary
gland. The pituitary gland signals the ovaries and testicles to make
hormones. Interference with these signals can affect egg production in
women and sperm production in men. This may or may not affect fertility
depending on the focus and dose of the radiation.
Surgery
Surgery on certain parts of the reproductive system can cause
infertility. For some cancers in women, a hysterectomy is part of the
treatment. A hysterectomy is surgery to remove the uterus either
through the vagina or through a cut made in the abdomen (belly). Once
this surgery is done, a woman cannot carry a child. The ovaries may be
removed (called an oophorectomy)
at the same time the uterus is taken out. When the woman's ovaries are
removed, she can't get pregnant because she no longer has any eggs. In
some cases of early stage ovarian or cervical cancer, the surgeon will
try to save one ovary, if possible, to preserve eggs. Keeping at least
one ovary also preserves the hormones that prevent menopause symptoms
like hot flashes and vaginal dryness. Some women with small cervical
cancers can have a new surgery called a trachelectomy,
which removes the cervix but leaves the uterus behind so a woman can
carry a pregnancy.
Sometimes surgery can cause scarring in the fallopian tubes.
These scars may block the tubes and prevent eggs from traveling to meet
the sperm, becoming fertilized, and moving on to the uterus to be
implanted.
Other treatments
Hormone therapies used to treat breast cancer or other cancers
can affect your ability to have a child. The effect of some of the
newer treatments on fertility and pregnancy, like vaccines, immune
therapies, or biological response modifiers, is not yet known. It is
always best to talk to your doctor, nurse, or other member of your
health care team about your treatment and its possible affect on your
sexual function and fertility.
Go back to Fertility
and Cancer: What Are My Options?
Last Medical Review: 07/23/2009
Last Revised: 07/23/2009
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