For cancer survivors who can have children, two new studies led by researchers at Fred Hutchinson Cancer Research Center may help alleviate fears that their childhood disease will adversely affect their newborns.
The studies, both published in Archives of Pediatrics & Adolescent Medicine, found few risks to babies born to parents who underwent cancer treatment in childhood or adolescence. The most significant finding was among women cancer survivors, who had a greater risk of giving birth to preterm and low birth weight infants compared with the general population.
Among female cancer survivors, 15% of births were preterm vs 10% among women who never had cancer. However, babies born to female cancer survivors had no increased risk of birth defects or infant death.
In the other study, babies fathered by male childhood cancer survivors had a borderline risk of low birth weight but no increased risk of prematurity, being small for gestational age, or having birth defects when compared with controls.
“The take-home message overall is positive: If you had cancer as a younger person and you are able to have children then most likely your children will be fine,” Eric Chow, MD, PhD, corresponding author and research associate in the Hutchinson Center's Clinical Research and Public Health Sciences divisions, said in a news release. “Most of the other side effects that people have the most concern about—birth defects and more serious maternal complications during pregnancy—we didn't find.”
Dr. Chow, who is also a pediatric oncologist, recommended that pregnant women who had cancer in childhood should seek prenatal care early in their pregnancies and make sure their physicians and obstetricians know about their cancer history. Close monitoring may help prevent early births and underweight newborns.
A possible explanation for the increased rates of preterm delivery and underweight newborns among female cancer survivors is that some cancer treatments may affect the growth of and blood flow to the uterus during pregnancy, Dr. Chow explained.
Previous studies, he noted, have shown that radiation therapy to the uterus can increase the chances of subsequent preterm labor and low birth weight.
For the two papers, Dr. Chow and the principal investigator, Beth Mueller, PhD, a cancer and reproductive health epidemiologist in the Public Health Sciences Division of Fred Hutchinson, used data from NIH SEER cancer registries in Seattle, Detroit, Salt Lake City and Atlanta.
Boys and girls were identified who were diagnosed with cancer before the age of 20 between 1973 and 2000. Linked birth records from the four regions identified the first live births to these survivors after diagnosis. A total of 1,898 offspring of female cancer survivors were identified and their outcomes were compared with 14,278 controls selected from birth records. The study identified 470 offspring of male cancer survivors and compared them with 4,150 controls.