Cancer radiation during pregnancy safe for unborn child

18 April 2024
Cancer radiation during pregnancy is safe for the unborn child, a long-term study from UZ Leuven has shown. The research team brings long-term results of the psychological and physical impact on a child after radiotherapy in the mother during pregnancy for the first time.

The lack of long-term results about the impact of radiotherapy on the child during pregnancy has been the cause of a lot of discussions in the medical world. Doctors only had technical data as a benchmark, such as data about radiation after nuclear disasters and the impact on the population. Therefore, doctors often chose to err on the side of caution and preferred not to give radiotherapy to a pregnant mother with cancer. This can obviously affect the success rate of cancer treatment.

Safety barriers

Between 2005 and 2023, the Leuven gynaecologist prof. dr. Frédéric Amant and his team examined 43 children from mothers that underwent cancer radiation during their pregnancy. It concerns children from various ages. The study was a combination of intelligence tests, attention and memory tests, medical exams, behaviour tests and questionnaires for the parents. 

The results of the studies are clear: children who were prenatally exposed to radiotherapy showed no long-term difference on neurocognitive, psychosocial or physical level in comparison with their peers. As long as the safety barriers are not crossed, radiotherapy of the upper body in the early stages of the pregnancy does not appear to be harmful for the unborn child. "From now on, doctors across the world can rely on a medical study rather than theoretic models", says professor Amant, principal investigator of the study.

Our study will help doctors internationally make a decision about cancer radiotherapy in pregnant women
prof. dr. Frédéric Amant

Radiotherapy of the upper body is an important part of the treatment for e.g. brain tumours, thyroid tumours, breast cancer, Hodgkin lymphoma, eye tumours or head- and neck cancer. Until today, doctors looked for an alternative for radiotherapy, such as chemo, for pregnant women with that type of tumours. But by deviating from the standard treatment, the chances of recovery may be slimmer. Professor's Amant research team has already shown in previous studies that chemotherapy during the pregnancy is safe for the unborn child.

Reassurance for the pregnant mother

Prof. dr. Frédéric Amant, gynaecologist at UZ Leuven and principal investigator of the study: “This new study is first and foremost a reassurance for pregnant mothers: if they are affected by cancer and would benefit from radiotherapy, they need not fear the consequence on their unborn baby. Depending on the position of the tumour in the body, and the stage of the pregnancy, doctors can choose to go for radiotherapy. Because the need for radiation in a pregnant mother is quite rare, there were no data about the long-term consequences for the child. Therefore, there were many different guidelines and procedures that differed from country to country and from hospital to hospital. Our study will now help doctors internationally who have to make a decision on whether to give radiotherapy.”

The study was recently published in The Lancet Child & Adolescent Health. The study was made possible with the support of Kom Op Tegen Kanker, KWF Kankerbestrijding, Fonds Wetenschappelijk Onderzoek and Stichting Tegen Kanker. The study was a close collaboration between prof. dr. Frédéric Amant, prof. dr. Lieven Lagae, prof. dr. Jurgen Lemiere, prof. dr. Maarten Lambrecht, prof. dr. Kristel Van Calsteren and Indra Van Assche.

Last edit: 22 May 2024