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Cancer in Pregnancy


Lara A. Friel

, MD, PhD, University of Texas Health Medical School at Houston, McGovern Medical School

Reviewed/Revised Sep 2023

Because embryonic tissues grow rapidly and have a high DNA turnover rate, they resemble cancer tissues and are thus very vulnerable to antineoplastic drugs. Many antimetabolites and alkylating drugs (eg, busulfan, chlorambucil, cyclophosphamide, 6-mercaptopurine, methotrexate) can cause fetal abnormalities. Methotrexate is particularly problematic; use during the 1st trimester increases risk of spontaneous abortion and, if the pregnancy continues, multiple congenital malformations. Although pregnancy often concludes successfully despite cancer treatment, risk of fetal injury due to treatment leads some women to choose pregnancy termination.

Diagnosis and management of cancer during pregnancy or the postpartum period require a multidisciplinary team including oncologists and maternal-fetal medicine specialists. Patient education and shared decision making is important to ensure the patient can make an informed decision.

Breast cancer

Cervical cancer

Cervical cancer can develop during pregnancy, and an abnormal Papanicolaou (Pap) test should not be attributed to the pregnancy itself. Abnormal Pap tests are followed by colposcopy and directed biopsies when indicated. Colposcopy does not increase risk of an adverse pregnancy outcome. Biopsies are done only if high-grade cervical intraepithelial neoplasia or cervical cancer is suspected. If biopsy is required, expert colposcopic evaluation and consultation with the pathologist are recommended because the biopsy may cause hemorrhage and preterm labor.

For carcinoma in situ (Federation of Gynecology and Obstetrics [FIGO] stage 0—see table ) and microinvasive cancer (stage IA1), treatment is often deferred until after delivery because at these stages, cancer progresses very slowly and pregnancy can be completed safely without affecting the woman's prognosis.

If invasive cancer (FIGO stage IA2 or higher) is diagnosed, pregnancy should be managed in consultation with a gynecologic oncologist. If invasive cancer is diagnosed during early pregnancy, immediate therapy appropriate for the cancer is usually recommended. If invasive cancer is diagnosed after 20 weeks and if the woman accepts the unquantified increase in risk, treatment can be deferred until into the 3rd trimester (eg, 32 weeks) to maximize fetal maturity but not delay treatment too long. For patients with invasive cancer, cesarean delivery with radical hysterectomy rather than vaginal delivery is done.

Other gynecologic cancers

Rectal cancer

Rectal cancers Colorectal Cancer Colorectal cancer is extremely common. Symptoms include blood in the stool and change in bowel habits. Diagnosis is by colonoscopy. Treatment is surgical resection and chemotherapy for nodal... read more Colorectal Cancer may require hysterectomy to ensure complete tumor removal. Cesarean delivery may be done as early as 28 weeks, followed by hysterectomy so that aggressive cancer treatment can be started.

Leukemia and Hodgkin lymphoma

Antineoplastic agents typically used to treat lymphoma increase risk of fetal loss and congenital malformations.

Because leukemias can become fatal rapidly, treatment is given as soon as possible, without any significant delay to allow the fetus to mature.

If Hodgkin lymphoma is confined to above the diaphragm, radiation therapy may be used; the abdomen must be shielded. If lymphoma is below the diaphragm, abortion may be recommended.


  • 1. Amant F, von Minckwitz G, Han SN, et al: Prognosis of women with primary breast cancer diagnosed during pregnancy: results from an international collaborative study. J Clin Oncol 31(20):2532-2539, 2013. doi:10.1200/JCO.2012.45.6335

  • 2. Shao C, Yu Z, Xiao J, et al: Prognosis of pregnancy-associated breast cancer: a meta-analysis. BMC Cancer 20(1):746, 2020. doi:10.1186/s12885-020-07248-8

  • 3. Johansson ALV, Fredriksson I, Mellemkjaer L, et al. Cancer survival in women diagnosed with pregnancy-associated cancer: An overview using nationwide registry data in Sweden 1970-2018. Eur J Cancer 155:106-115, 2021. doi:10.1016/j.ejca.2021.07.008

Drugs Mentioned In This Article

Drug Name Select Trade
Busulfex, Myleran
Cyclophosphamide, Cytoxan, Neosar
Purinethol, PURIXAN
Jylamvo, Otrexup, Rasuvo, RediTrex, Rheumatrex, Trexall, Xatmep
NOTE: This is the Professional Version. CONSUMERS: View Consumer Version
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