The diagnosis of cancer during pregnancy occurs in about 1 out of every 1,000 women, according to a 2004 article in the Lancet Oncology journal by Elyce Cardonick and Audrey Iacobucci. If the chemotherapy treatment cannot wait until after the pregnancy is completed or if termination of the pregnancy is not an option, a woman can receive chemotherapy during pregnancy. Chemotherapy during the first trimester should be avoided because of the increased risk of birth defects; chemotherapy during the second and third trimester--while generally safe--can still be associated with after affects.
Birth Defects and Other Problems During the First Trimester
Because the organs of the fetus develop during the first trimester, chemotherapy during the first trimester of pregnancy increases the risk of damage to the fetus according to the American Society of Clinical Oncology website. Chemotherapy drugs destroy fast-growing cells such as fetal cells and can cause birth defects, miscarriage or fetal death. This risk of defects can be dependent the specific chemotherapy drug like 5-fluorouracil or methotrexate.
Premature Birth
Chemotherapy during the second and third trimesters is less risky to the fetus than chemotherapy during the first trimester. Premature birth has been associated with chemotherapy during pregnancy according to the National Cancer Institute.
Low Birth Weight
Another after effect of chemotherapy during pregnancy is low birth weight of the baby. Chemotherapy during pregnancy increases the risk of intrauterine growth retardation, which is poor growth of a fetus in the womb. Problems with maternal nutrition--caused by either the cancer itself or anorexia associated with the chemotherapy--can also lead to babies with small birth weights as noted in a 2004 article in the Lancet Oncology journal by Elyce Cardonick and Audrey Iacobucci.
Low Blood Cell Counts
Chemotherapy during pregnancy can cause low blood cell counts due to the impact on the bone marrow. Pregnant women often have problems with anemia in general; the combination can cause significant anemia in the mother. According to a 2004 article in the Lancet Oncology journal by Elyce Cardonick and Audrey Iacobucci, the medication epoietin--which stimulates blood cell formation--can be used in this situation. Chemotherapy can affect the levels of infection-fighting cells in the mother and fetus as well. According to the BreastCancer.org website, many women do not receive chemotherapy for one month before the birth to allow the bone marrow a chance to recover; this lowers the risk of infection in both the mother and infant at birth.
References
- American Society of Clinical Oncology (ASCO): Pregnancy and Cancer
- "The Lancet Oncology"; Use of Chemotherapy During Human Pregnancy; Elyce Cardonick and Audrey Iacobucci; 2004.
- BreastCancer.org: Is Treatment Safe for Your Baby?
- American Cancer Society: Sex, Fertility, and Chemo
- National cancer Institute: Breast Cancer Treatment and Pregnancy (PDQ®)
