Cancer in pregnancy

The number of pregnant women and 1 year postpartum newly diagnosed with a malignant disease annually in the U.S. is approximately 1 per 1000 pregnancies.

About 70,000 US women of reproductive age are diagnosed with cancer, and survival rates for this population exceed 80%.

Transmission of maternal cancer to offspring is extremely rare, estimated to occur in approximately one infant per every 500,000 mothers with cancer.

Melanoma, breast cancer, cervical cancer, leukemia and lymphoma are the most common malignancies that occur during pregnancy.

The incidence of simultaneous cancer and pregnancy is 0.1 – 0.2%.

Approximately 1 in 3000 pregnancies is associated with concurrent breast cancer.

The incidence of cancer during pregnancy or lactation is increasing, as the age of childbearing is increasing.

The increased incidence of pregnancy associated cancer may also be attributed to improvements in diagnostic testing, awareness of genetic factors and subsequent screening, and expansion of population based screening programs.

Pregnancy associated cancers are overwhelmingly diagnosed in the postpartum period: only 25% are diagnosed during pregnancy.

The time of diagnosis can be attributable to increased healthcare encounters in the ante-natal and post natal periods, and possibly due to hesitancy to perform diagnostic tests that might be harmful during pregnancy.

Cancer is the second most common  cause of death for women of childbearing age.


As the maternal child bearing age increases, the number of cancers diagnosed during pregnancy is expected to rise.


 The most common cancers affecting pregnant women are: breast cancer, cervical cancer, lymphoma, ovarian cancer, leukemia, colorectal cancer, and melanoma.

The prognosis of breast, melanoma, and vulvar cancer are worse when diagnosed during pregnancy.

Medical decision making during pregnancy is complex involving ethical and emotional issues, and they need to weigh the potential benefits to the mother against the risks of the fetus.


The gestational age of the fetus is a critical factor in treatment planning in general, chemotherapy should be avoided during the first trimester, but many types of oncologic therapies can be administered safely during the second or third trimester.

Surgery is possible during pregnancy ideally during the second  trimester.

Radiation therapy is generally avoided during pregnancy except in rare scenarios where potential benefits exceed the risks.

The diagnosis of cancer during pregnancy is often delayed because many signs and symptoms including fatigue, breast changes, anemia, nausea, and or rectal bleeding may mimic those of pregnancy.


Almost 2/3 of cancer cases associated with pregnancy are diagnosed after delivery.


Ultrasound is the preferred imaging modality during pregnancy. 


MRI contrast medium gadolinium crosses the placenta should not be used during pregnancy.


Radiation exposure above safe levels has been associated with fetal demise, malformations, mental retardation, and secondary cancers with higher risk at earlier gestational age.


Most diagnostic imaging modalities with appropriate shielding techniques expose the fetus to doses of radiation far below safe levels.


Pet scan/CT scan imaging going confers  higher doses of radiation and should be postponed until after pregnancy, whenever possible.


Cancer treatment modalities including chemotherapy, radiation, hormone therapy come and surgery all have possible adverse effects on a fetus.

It is recommended that chemotherapy be prescribed in pregnant patients with cancer based on weight, and gestational pharmacokinetic changes and should not be adapted because of maternal survival seems to be unaffected when this dosing strategy is used.

Pregnant patients with cancer who receive multi-drug chemotherapy in the first trimester have an increased risk of spontaneous abortion, fetal demise and fetal malformations (Pereg D).

Pregnancy termination should be considered in certain cases of aggressive disease such as acute leukemia, or advanced cancer in early pregnancy.
The pharmacology of chemotherapeutic drugs vary during pregnancy because of the physiology of pregnancy including enhanced renal clearance, increased hepatic function, varied G.I. absorption, and the creation of a fluid filled third compartment the amniotic fluid that seaQuest use water soluble drugs.
Because blood volume and total body water increased during pregnancy there is likely drug delusion from the increase in the volume of distribution.
No pharmacogenetic studies of chemotherapy have been done during pregnancy.
The teratogenicity risks of chemotherapy depend on gestational age, agent and dosage,  as well as the risk of placental transfer.
The first trimester has the highest risk., particularly during the period of organogenesis over the first several weeks with major congenital malformations, fetal demise, impaired organ function, in spontaneous abortion are most likely.
During the second and third trimesters there is no definite associations with significant teratogenic effects of chemotherapy.
The effect of pregnancy and the prognosis of cancer is contradictory.
There is an increased risk of small for gestational age neonates in pregnant women with cancer, especially those treated with platinum based chemotherapy.
No studies have shown that the maternal prognosis is improved with termination of pregnancy.
Transmission of maternal cancer to offspring has been reported in 18 cases.
In these cases cancer of the blood, skin, lungs, and cervix in the mother was presumably transmitted hematogenously through trans placental mother-to-fetus Transmission and often involved dissemination of maternal tumor cells to multiple organs of the brain, bone, liver, and soft tissues in the infant.
For reported such cases were in children younger than two years, and in some cases spontaneous tumor regression in the affected offspring was noted.
Trans placental transmission in the fetus is rare because of the placental barrier in the fetal alloimmune response.
Mother-to-infant Transmission of tumor in the birth canal during vaginal delivery is a theoretical consideration.
If a mother has cervical cancer the implant can be exposed to tumor cells influe is in the birth canal and could aspirate tumor cells into the lungs.
Delivery after 37 weeks is the goal, if achievable without compromising maternal safety.
If preterm delivery is considered to expedite maternal treatment, the potential for adverse outcomes in the fetus is taken into consideration.
For women under treatment during pregnancy, delivery time should be coordinated to avoid cytopenias at delivery.
Platelets may be transfused to reach platelet count of greater than 30,000 for vaginal delivery or greater than 50,000 for cesarean section.
Hormonal therapies are not recommended during pregnancy and include tamoxifen and aromatase inhibitors which may be associated with birth defects.
HER2 inhibitors are contraindicated in pregnancy because of the important role of HER2
in fetal development.
CTLA-4 and PD-1 inhibitors have substantial risks for the fetus, during pregnancy.
If anticoagulation is required the preferred antithrombotic agent is low molecular weight heparin, which does not cross the placenta and is considered safe in pregnancy.
There is no evidence that intrauterine exposure of chemotherapy to a fetus results in a definite long-term health problem.

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