Facts about Cancer and pregnancy

1 When making treatment decisions, factors to consider include the stage of pregnancy, the type, location and size of the cancer, and the wishes of the patient and her family.

2 Pregnancy can mask some of the symptoms.

Breast cancer, for instance, occurs once in every 3,000 pregnancies, but the enlarging breast can hide the telltale lumps, says Dr Ong Kong Wee, who heads the SingHealth Duke-NUS Breast Surgery Centre. Sufferers are also likely to be diagnosed later. 

3 Some treatments can harm the foetus, especially during the first three months when the baby's vital organs are forming.

Dr Christopher Chong of Chris Chong Women and Urogynae Centre explains: "Chemotherapy (at that point) can damage the organs and cause abnormality, damage the cells or genes and increase the risk of organ failure or cancer in the unborn child."

4 Doctors are more likely to begin chemotherapy after the first trimester, as the placenta begins to protect the developing foetus, preventing most of the drugs from crossing over to the baby.

5 A known complication of administering chemotherapy in the late stage of pregnancy is that it can cause premature labour and babies that are of low birth weight, says Dr Quek Swee Chong, clinical director of Parkway Gynaecology Screening and Treatment Centre.

Radiotherapy is usually not administered as the high doses of radiation can harm the foetus.

Dr Quek says that most times, doctors will prefer to deliver the baby as soon as possible.