It is among the most delicate and difficult dilemmas in medicine: Should a pregnant woman who has received a cancer diagnosis begin treatment before her child is born? Some hesitant doctors counsel women to deliver preterm or even terminate the pregnancy first.
But a study of more than 100 children who were exposed to cancertreatment during the last two trimesters of their mother’s pregnancyshowed they had normal cognitive and cardiac function, researchers reported on Monday.
“The main message of this study is that termination of pregnancy is not necessarily warranted, and that early preterm delivery to be able to do cancer treatment isn’t warranted, either,” said Dr. Elyce H. Cardonick, a maternal-fetal specialist at Cooper Medical School of Rowan University in Camden, N.J., who was not involved in the new research.
The study, published in The New England Journal of Medicine, was presented Monday at the European Cancer Congress in Vienna.
“We didn’t find any difference in cardiac functioning or cognitive function between children exposed to cancer treatment in utero and the control group,” said Dr. Frédéric Amant, the lead author of the study and a professor of obstetrics and gynecology at the Katholieke Universiteit Leuven in Belgium.
“To some extent, it’s surprising because cancer treatment is quite toxic,” he said, “and we know most chemotherapy drugs cross the placenta.”
None of the women underwent chemotherapy in the first trimester because the risk of causing serious birth defects is greatest during that period. Instead, the researchers assessed the mental development of 129 children who had been exposed to chemotherapy, radiation or surgery later in pregnancy, as the fetal brain continues to develop.
The cognitive findings were based on a neurological exam and a test called the Bayley Scales of Infant Development that researchers conducted on the children at 18 months, 3 years or both.
More than half of the mothers-to-be had breast cancer, and 16 percent had blood cancers.
More than 60 percent of children of mothers with cancer were born earlier than 37 weeks, compared with roughly 8 percent in the general population. Most mothers were induced into labor so cancer treatment could continue. Dr. Amant said he hoped his team’s data would persuade clinicians to stop this practice.
The authors accounted for prematurity by matching those children to a control group of the same gestational age born to mothers without cancer from some of the same countries, including Belgium and the Czech Republic.
The number of chemotherapy cycles did not affect cognitive outcomes for the children.
However, the degree of prematurity was related to worse cognitive outcome in both study groups. After adjusting for factors like parental education, every added week in the womb led to roughly two more points on the Bayley test, the study found. (The higher the score, the better a child’s mental development.)
“Prematurity is a problem for these children, but chemotherapy is not,” Dr. Amant said.
Some commonly used chemotherapy agents like doxorubicin can damage the heart muscle in adults, depending on the dose. So the researchers assessed the hearts of 47 of the 129 children in the study using electrocardiography and echocardiography.
At age 3, “the cardiac development of these babies was pretty normal,” said Dr. Michael F. Greene, the chief of obstetrics at Massachusetts General Hospital, who was not involved with the study. The groups did not have significant differences in the size of the heart chambers or the muscle’s ability to pump blood.
In an accompanying editorial, Dr. Greene expressed “cautious optimism” about the study and said it offered reassurance to pregnant women undergoing cancer treatment that “it’s not inevitably a horrible problem for their offspring.”
The study had limitations. Not all chemotherapy drugs were studied, and no novel targeted anticancer drugs were examined. The numbers of participants was not large, but cancer in pregnancy is rare, occurring in only one of every 1,000 pregnancies.
“This paper has very detailed standardized follow-up on children,” Dr. Cardonick said, adding that the multicenter study, with so many cases, would provide valuable information to physicians and patients.
It remains to be seen if doctors will be swayed by the study’s findings. Dr. Cardonick, who maintains a registry of cases of cancer in pregnancy, has heard of a couple of “sad cases” where “a patient was denied cancer treatment during pregnancy, and died soon after the baby was born, because there was no confidence that cancer treatment during pregnancy would be tolerated by the fetus.”
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