Chemotherapy in pregnancy may not harm babies

[Posted: Mon 20/08/2012 by Gillian Tsoi www.irishhealth.com]

Pregnant breast cancer patients, who undergo chemotherapy, do not appear to be at higher risk of complications, according to a new study.

The study examined over 400 women from across Europe who were diagnosed with early-stage breast cancer while pregnant. Of these, 197 (48%) had chemotherapy while they were pregnant.

Their newborn babies were then examined for any ill effects that could be caused by the cancer drugs.

The babies of mothers had undergone chemotherapy while pregnant had, on average, a lower birth weight than those whose mothers had not had chemotherapy.

Babies exposed to chemotherapy in the womb appeared to have no higher risk of birth defects, no more frequent blood disorders or alopecia than those whose mothers did not receive chemotherapy while pregnant.

The number of chemotherapy cycles received during pregnancy did not appear to affect the babies' birth weight, leading the researchers to suggest that the lower birth weight is not clinically meaningful.

"If our findings are confirmed by other studies, breast cancer during pregnancy could be treated as it is in non-pregnant women without putting foetal and maternal outcomes at substantially increased risk," said Professor Sibylle Loibl, of the German Breast Group, which led the study.

"In the general population, about 10-15% of infants are born preterm, but in our study, 50% of women with breast cancer delivered preterm, with 23% delivering before the 35th week of gestation. More complications were reported in the group of infants exposed to chemotherapy than in the group not exposed to chemotherapy.

However, most complications were reported in babies who were delivered prematurely, irrespective of exposure to chemotherapy."

"Our findings emphasise the importance of prioritising a full-term delivery in women who undergo chemotherapy while pregnant," adds Professor Loibl.

She explained that illness and mortality in newborn babies is directly related to the baby's gestational age at delivery.

"This is an important clinical message because the decision to deliver the foetus preterm is often taken without medical indication. Our work suggests that treating patients with breast cancer while pregnant is possible, and there is no need to interrupt the pregnancy or receive inferior therapy."

The experts have pointed out that further research is needed to examine how chemotherapy doses should be worked out for pregnant patients, and longer-term studies need to assess the effect of in utero chemotherapy on children as they grow older.

The article was published online in The Lancet Oncology journal.

To view the Irishhealth.com Pregnancy Clinic, click here.