While the incidents may be rare, a new study suggests that there is a possibility for a mom with cancer to transmit the disease to her baby during delivery.

Japanese researchers revealed that there was rare case of two siblings who acquired cancer from their pregnant mother at the time of delivery. The experts on the disease said that the boys were able to "breathe in" the cancer cells from the tumor of their mother when they were born.

The study titled, "Vaginal Transmission of Cancer from Mothers with Cervical Cancer to Infants" which appeared in the New England Journal of Medicine, revealed that the two boys, a six-year-old and a 23-month-old had lung cancer, which researchers found were an "exact genetic match" to their mother's cervical cancer at the time that they were born.

Dr. Ayumu Arakawa, a pediatric oncologist at the National Cancer Center located in Tokyo, said that they believe that the tumors in the children were brought about through vaginal transmission from the mom to the baby. Arakawa said that the transmission happened through "aspiration," which in layman terms refers to breathing. She said that the infants, during birth, were able to breathe in cancer-contaminated vaginal fluids.

The researchers noted that the transmission of maternal cancer to the baby is a very rare instance. They estimated that the occurrence takes place in only one infant per every 500,000 mothers who have cancer. On top of that, there is only one in every 1,000 live births that involves a mother with cancer.

In the case when maternal transmission of cancer to the baby would occur, it would presumably be transmitted hematogenously, or through transplacental mother-to-fetus transmission. Cancers of the skin, lungs, blood, and cervix are among the cancers mentioned by researchers.

The researchers further explained that the transmission of the tumor from the mother to the infant in the birth canal during natural delivery is theoretically possible. They noted that if the mom has cervical cancer, then the baby could be exposed to the tumor cells that are in the fluids in the birth canal and the baby can breathe in these cells into the lungs.

There was already a small number of cases previously observed, which involve cancer cells that travel across the placenta into the fetus. The most usual cancers that fetuses contract because of transplacental transmission are lymphoma, melanoma, and leukemia.

Transmission of cancer to baby
Rare case of transmitting cancer to baby during childbirth. Photo: Pixabay