Women diagnosed with cancer during pregnancy no longer need to choose between their own life and that of their baby. It is possible to save both.
A series of studies published in The Lancet and Lancet Oncology shows that children born to women given chemotherapy while they were growing in the womb developed as well as children in the general population.
About one in 1,000 pregnancies is affected by cancer and in the past women have faced a terrible choice: delay treatment until the baby is born, putting their own life at risk, start treatment while pregnant and risk damaging the baby, or terminate the pregnancy.
Now the trend is to preserve pregnancy wherever possible and the evidence shows the outcomes for mother and baby are good.
Chemotherapy involves administering toxic drugs to kill the cancer but which also kill healthy cells in the mother's body. Its effects on the foetus have been unclear but a study of 68 women who each had three to four cycles of chemotherapy during pregnancy showed their children were unaffected.
Tests of cognitive ability on the children were "within normal ranges", the researchers from Leuven Cancer Institute in Belgium say. Only those born prematurely had lower scores of cognitive ability but the researchers say this applies in the general population too.
"Our findings do not support a strategy of delay in chemotherapy or [induced] pre-term delivery with [subsequent] chemotherapy to avoid harm to the foetus," the authors write.
In a second paper, researchers from the Institut Gustave Roussy say women must not have chemotherapy in early pregnancy when it can harm the foetus but from the second trimester (12 weeks) onwards evidence shows it is safe. "The use of chemotherapy during pregnancy helps increase the chance of foetal preservation. Children exposed to chemotherapy in utero after the first trimester do not seem to have more congenital abnormalities," the authors say.
However, they admit that women with advanced cervical cancer would benefit most from a combination of chemotherapy and radiotherapy which is likely to necessitate termination of the pregnancy.
The authors of a third paper in the series say chemotherapy for breast cancer can be given in the second and third trimesters and termination of the pregnancy "does not seem to improve maternal outcome". But they add that the decision whether to continue or end the pregnancy is a personal one.
Case study: 'Certain drugs don't pass across the placenta. Not everyone knows that'
Caroline Swain's positive pregnancy test should have brought joy. She had been trying for a baby with her husband to be a sibling to their first-born, Max. Instead the result brought terror. Aged 35, she had taken the test as a precaution, before going into hospital for treatment for breast cancer, which had just been diagnosed
"I went through all the emotions. Will I live to see my child grow up? Will I live long enough for him or her to know me? We wanted to save the baby but the first issue was: would that be possible?"
It was. Caroline's consultant at Southend Hospital in Essex advised that if she had a mastectomy immediately and waited until she was 12 weeks pregnant to start chemotherapy, her baby should be safe. Luke was born and is now nine.
"When my consultant told me it was possible to have the baby and the treatment it was unbelievable. Certain drugs don't pass across the placenta. Not everyone is aware of that. We are very lucky."