MONDAY, Sept. 28, 2015 (HealthDay News) -- Pregnant women who are diagnosed with cancer do not need to delay treatment or end their pregnancy, a new study found.
The study included 129 children in Europe whose mothers were diagnosed with cancer during pregnancy, as well as a control group of 129 children born to women without cancer. The children's physical and mental health were assessed when they were 18 months and 3 years of age.
Among the children whose mothers were diagnosed with cancer during pregnancy, 69 percent were exposed to chemotherapy before birth, about 3 percent to radiation therapy and 5.4 percent to both chemotherapy and radiation. A small number were exposed to trastuzumab (Herceptin) or interferon (less than 1 percent each), while about 10 percent were exposed to surgery alone.
About 11 percent of mothers with cancer did not receive treatment during pregnancy, according to the study presented Monday at the European Cancer Congress in Vienna, Austria. The study findings were published simultaneously in the New England Journal of Medicine.
"Compared to the control group of children, we found no significant differences in mental development among children exposed to chemotherapy, radiotherapy, surgery alone or no treatment," said Professor Frederic Amant, a gynecological oncologist at the University Hospitals Leuven in Belgium and Antoni van Leeuwenhoek Hospital in the Netherlands.
"Nor was the number of chemotherapy cycles during pregnancy, which ranged from one to ten, related to the outcome of the children," he added in a news release from the European Cancer Organization.
The researchers also found that preterm birth was more common among children born to mothers with cancer, regardless of whether the mothers received cancer treatment during pregnancy.
"In most cases, they were born prematurely due to a medical decision to induce preterm so as to continue cancer treatment after the delivery," Amant said. "In some cases preterm delivery was spontaneous and it is possible that cancer treatment plays a role in this. But we do not know what exactly triggers preterm delivery. It could be that chemotherapy induces preterm contractions or vaginal inflammation with preterm rupture of the membranes."
The most common cancers diagnosed in the mothers in the study were breast and blood cancers such as leukemia and lymphoma.
"Our results show that fear of cancer treatment is no reason to terminate a pregnancy, that maternal treatment should not be delayed and that chemotherapy can be given. The study also shows that children suffer more from prematurity than from chemotherapy, so avoiding prematurity is more important than avoiding chemotherapy," Amant said.
Added Professor Peter Naredi, scientific co-chair of the Congress: "These latest results should be reassuring for pregnant women who have been diagnosed with cancer and who will, naturally, be worrying about the best course of action not only for themselves but for their unborn child.
"While further follow-up of these children is required, the important message at this stage seems to be that doctors should not only start cancer treatment immediately, but should also try to maintain the pregnancy to as near full term as possible," added Naredi, who was not involved in the study.
The American Society of Clinical Oncology has more about cancer during pregnancy.