If your mother has cancer when she's pregnant is there any effect of the same on the child?

No, but.

Cancer during pregnancy is not an uncommon thing but cancer itself rarely affects the growing baby directly. The cancers that tend to occur during pregnancy are also more common in younger people.

These cancers include - Cervical Cancer, Breast Cancer, Thyroid Cancer, Melanoma, Gestational Trophoblastic Cancer.

Breast cancer happens to be the most common type diagnosed during pregnancy. It affects about 1 in 3,000 women who are pregnant. As breasts generally enlarge and change texture during pregnancy, symptoms of cancer might be difficult to detect. They might not seem to be abnormal. As a result, pregnant women with breast cancer may be diagnosed later than non-pregnant women. If you are pregnant, it may delay a cancer diagnosis. Some of the cancer symptoms like bloating, headaches, breast changes or rectal bleeding are also a common thing during pregnancy. But pregnancy can also identify cancer. For instance, a Pap test done during standard pregnancy care can detect cervical cancer or a USG performed during pregnancy may identify ovarian cancer.