Chemotherapy during pregnancy for cancer does not necessarily harm the baby: Study

By Dr. Ananya Mandal, MDFeb 13 2012

A new study suggests that babies whose mothers undergo cancer drug treatment during their pregnancy do not appear to suffer any long-term harm.

When a pregnant woman is diagnosed with cancer, she and her family and doctors are faced with difficult decisions about her health and that of her unborn child. It is known that giving chemotherapy in the first 12 weeks, when the baby's organs are still forming, raises the chances of birth defects. Postponing the treatment, however, could allow the cancer to spread. Over the last decade, doctors have been more willing to use chemotherapy after the first trimester, but there have been worries that the child's brain and heart could suffer damage.

Now researchers in the Lancet Oncology journal report that they have followed the progress of 70 children whose mothers had chemotherapy while they were in the womb – and their findings are reassuring.

The team began the study in 2005 when they started recruiting some children retrospectively and following others from birth. Every few years the children, who ranged in age from 18 months to 18 years, were given physical and mental development tests.

The children's thinking and reasoning capacity was similar to that of other children – but those born prematurely, often because it had been thought advisable to deliver the baby early to begin the mother's cancer treatment, had lower development scores than those who were born around term (40 weeks' gestation). Allowing for variables such as age, sex and country of birth, the child's IQ was 12 points higher for every extra month he or she spent in the womb.

Dr Frédéric Amant, from the Leuven cancer institute at the Katholieke Universiteit in Leuven, Belgium, and colleagues say in their paper that the difference was not down to the cancer treatment, but to prematurity. The same lower developmental scores are seen in all very premature babies. On behavior, hearing, general health and growth, the children did as well as any others. Their heart size and function was normal too.

“The situation remains challenging since in some situations an advanced cancer can be fatal for mother and fetus,” said Dr. Frédéric Amant of the Leuven Cancer Institute in Belgium, lead author of the report. “The patient and her partner should be informed about the different treatment options and the physician should explain that termination of pregnancy does not seem to improve maternal outcome, but the decision to continue or end the pregnancy is a personal one.”

As women have babies at a later age, the numbers of those diagnosed with cancer while pregnant is rising, the authors say. Although pregnancy does not increase the risk of breast cancer, the decision by some women to delay motherhood might be increasing the number of pregnant women with cancer, according Lillian Shockney, a breast cancer nurse at Johns Hopkins Hospital in Baltimore. “We know age is a risk factor, and so is having your first child after age 30,” said Shockney, who is also an associate professor of surgery, gynecology, oncology and obstetrics at Johns Hopkins University School of Medicine. Pregnancy also causes breast changes that can mask the signs of cancer, delaying the diagnosis. Only about 1 in 1,000 pregnant women face this dilemma.

Authors suggest cancer treatment should not be delayed if a pregnant woman needs it and that it may be more damaging to the child in the long term to wait and then deliver the baby prematurely. “We show that children who were prenatally exposed to chemotherapy do as well as other children,” conclude the authors. “The decision to administer chemotherapy should follow the same guidelines as in non-pregnant patients. In practice, it is possible to administer chemotherapy from 14 weeks gestational age onwards with specific attention to prenatal care.”

But they add that they cannot be sure there will be no effects on the children in years to come and more follow-up is needed to be sure the children will not have impaired fertility as adults or be more likely to get cancer themselves. “Only time will inform us of the full consequences, including fertility and secondary malignancies (especially if DNA damaging drugs are used), of foetal exposure to chemotherapy,” they say.

In an editorial in the journal, Dr Elyce Cardonick of the department of obstetrics and gynaecology at Cooper Medical School of Rowan University in New Jersey, said, “The study by Amant and colleagues has the potential to affect clinical practice: if we can present this reassuring data to pregnant women with cancer, women might be more likely to accept treatment during pregnancy when indicated.”

“Pregnant patients are warriors,” said Dr. Jane Kakkis, Leiva's surgical oncologist and medical director of breast surgery at Orange Coast Memorial Medical Center in Fountain Valley, Calif. “Most pregnant women are more concerned about their child's life, but they also want to be around to care for their baby.”

Dr. Richard Theriault, a professor of medicine at the MD Anderson Cancer Center in Texas, said he hoped the papers would change how doctors treat pregnant cancer patients. “Terminating a pregnancy is not always necessary,” said Theriault, who heads a program to treat pregnant women with cancer. He said a minority of pregnant women with cancer still get abortions. He said the placenta seems to act as a kind of filter for chemotherapy drugs, restricting their effects on the fetus. “There's the phenomenon of the bald mother who gives birth to a baby with a full head of hair,” he said. “It seems to suggest not as much gets to the baby as we thought.”